Class: Polars::Series

Inherits:
Object
  • Object
show all
Defined in:
lib/polars/series.rb

Overview

A Series represents a single column in a polars DataFrame.

Instance Method Summary collapse

Constructor Details

#initialize(name = nil, values = nil, dtype: nil, strict: true, nan_to_null: false, dtype_if_empty: nil) ⇒ Series

Create a new Series.

Examples:

Constructing a Series by specifying name and values positionally:

s = Polars::Series.new("a", [1, 2, 3])

Notice that the dtype is automatically inferred as a polars Int64:

s.dtype
# => Polars::Int64

Constructing a Series with a specific dtype:

s2 = Polars::Series.new("a", [1, 2, 3], dtype: :f32)

It is possible to construct a Series with values as the first positional argument. This syntax considered an anti-pattern, but it can be useful in certain scenarios. You must specify any other arguments through keywords.

s3 = Polars::Series.new([1, 2, 3])

Parameters:

  • name (String, Array, nil) (defaults to: nil) —

    Name of the series. Will be used as a column name when used in a DataFrame. When not specified, name is set to an empty string.

  • values (Array, nil) (defaults to: nil) —

    One-dimensional data in various forms. Supported are: Array and Series.

  • dtype (Symbol, nil) (defaults to: nil) —

    Polars dtype of the Series data. If not specified, the dtype is inferred.

  • strict (Boolean) (defaults to: true) —

    Throw error on numeric overflow.

  • nan_to_null (Boolean) (defaults to: false) —

    Not used.

  • dtype_if_empty (Symbol, nil) (defaults to: nil) —

    If no dtype is specified and values contains nil or an empty array, set the Polars dtype of the Series data. If not specified, Float32 is used.



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# File 'lib/polars/series.rb', line 35

def initialize(name = nil, values = nil, dtype: nil, strict: true, nan_to_null: false, dtype_if_empty: nil)
  # Handle case where values are passed as the first argument
  if !name.nil? && !name.is_a?(String)
    if values.nil?
      values = name
      name = nil
    else
      raise ArgumentError, "Series name must be a string."
    end
  end

  name = "" if name.nil?

  # TODO improve
  if values.is_a?(Range) && values.begin.is_a?(String)
    values = values.to_a
  end

  if values.nil?
    self._s = sequence_to_rbseries(name, [], dtype: dtype, dtype_if_empty: dtype_if_empty)
  elsif values.is_a?(Series)
    self._s = series_to_rbseries(name, values)
  elsif values.is_a?(Range)
    self._s =
      Polars.arange(
        values.first,
        values.last + (values.exclude_end? ? 0 : 1),
        step: 1,
        eager: true,
        dtype: dtype
      )
      .rename(name, in_place: true)
      ._s
  elsif values.is_a?(Array)
    self._s = sequence_to_rbseries(name, values, dtype: dtype, strict: strict, dtype_if_empty: dtype_if_empty)
  else
    raise ArgumentError, "Series constructor called with unsupported type; got #{values.class.name}"
  end
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class Polars::ExprDispatch

Instance Method Details

#!=(other) ⇒ Series

Not equal.

Returns:



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# File 'lib/polars/series.rb', line 175

def !=(other)
  _comp(other, :neq)
end

#%(other) ⇒ Series

Returns the modulo.

Returns:



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# File 'lib/polars/series.rb', line 238

def %(other)
  if is_datelike
    raise ArgumentError, "first cast to integer before applying modulo on datelike dtypes"
  end
  _arithmetic(other, :rem)
end

#&(other) ⇒ Series

Bitwise AND.

Returns:



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# File 'lib/polars/series.rb', line 138

def &(other)
  if !other.is_a?(Series)
    other = Series.new([other])
  end
  Utils.wrap_s(_s.bitand(other._s))
end

#*(other) ⇒ Series

Performs multiplication.

Returns:



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# File 'lib/polars/series.rb', line 224

def *(other)
  _arithmetic(other, :mul)
end

#**(power) ⇒ Series

Raises to the power of exponent.

Returns:



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# File 'lib/polars/series.rb', line 248

def **(power)
  if is_datelike
    raise ArgumentError, "first cast to integer before raising datelike dtypes to a power"
  end
  to_frame.select(Polars.col(name).pow(power)).to_series
end

#+(other) ⇒ Series

Performs addition.

Returns:



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# File 'lib/polars/series.rb', line 210

def +(other)
  _arithmetic(other, :add)
end

#-(other) ⇒ Series

Performs subtraction.

Returns:



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# File 'lib/polars/series.rb', line 217

def -(other)
  _arithmetic(other, :sub)
end

#-@ ⇒ Series

Performs negation.

Returns:



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# File 'lib/polars/series.rb', line 258

def -@
  0 - self
end

#/(other) ⇒ Series

Performs division.

Returns:



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# File 'lib/polars/series.rb', line 231

def /(other)
  _arithmetic(other, :div)
end

#<(other) ⇒ Series

Less than.

Returns:



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# File 'lib/polars/series.rb', line 189

def <(other)
  _comp(other, :lt)
end

#<=(other) ⇒ Series

Less than or equal.

Returns:



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# File 'lib/polars/series.rb', line 203

def <=(other)
  _comp(other, :lt_eq)
end

#==(other) ⇒ Series

Equal.

Returns:



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# File 'lib/polars/series.rb', line 168

def ==(other)
  _comp(other, :eq)
end

#>(other) ⇒ Series

Greater than.

Returns:



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# File 'lib/polars/series.rb', line 182

def >(other)
  _comp(other, :gt)
end

#>=(other) ⇒ Series

Greater than or equal.

Returns:



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# File 'lib/polars/series.rb', line 196

def >=(other)
  _comp(other, :gt_eq)
end

#[](item) ⇒ Object

Returns elements of the Series.

Returns:

Raises:

  • (ArgumentError) 


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# File 'lib/polars/series.rb', line 265

def [](item)
  if item.is_a?(Integer)
    return _s.get_idx(item)
  end

  if item.is_a?(Range)
    return Slice.new(self).apply(item)
  end

  raise ArgumentError, "Cannot get item of type: #{item.class.name}"
end

#[]=(key, value) ⇒ Object

Sets an element of the Series.

Returns:



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# File 'lib/polars/series.rb', line 280

def []=(key, value)
  if value.is_a?(Array)
    if is_numeric || is_datelike
      set_at_idx(key, value)
      return
    end
    raise ArgumentError, "cannot set Series of dtype: #{dtype} with list/tuple as value; use a scalar value"
  end

  if key.is_a?(Series)
    if key.dtype == :bool
      self._s = set(key, value)._s
    elsif key.dtype == :u64
      self._s = set_at_idx(key.cast(:u32), value)._s
    elsif key.dtype == :u32
      self._s = set_at_idx(key, value)._s
    else
      raise Todo
    end
  end

  if key.is_a?(Array)
    s = Utils.wrap_s(sequence_to_rbseries("", key, dtype: :u32))
    self[s] = value
  elsif key.is_a?(Integer)
    # TODO fix
    # self[[key]] = value
    set_at_idx(key, value)
  else
    raise ArgumentError, "cannot use #{key} for indexing"
  end
end

#^(other) ⇒ Series

Bitwise XOR.

Returns:



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# File 'lib/polars/series.rb', line 158

def ^(other)
  if !other.is_a?(Series)
    other = Series.new([other])
  end
  Utils.wrap_s(_s.bitxor(other._s))
end

#_hash(seed = 0, seed_1 = nil, seed_2 = nil, seed_3 = nil) ⇒ Series

Hash the Series.

The hash value is of type :u64.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s._hash(42)
# =>
# shape: (3,)
# Series: 'a' [u64]
# [
#         2374023516666777365
#         10386026231460783898
#         17796317186427479491
# ]

Parameters:

  • seed (Integer) (defaults to: 0) —

    Random seed parameter. Defaults to 0.

  • seed_1 (Integer) (defaults to: nil) —

    Random seed parameter. Defaults to seed if not set.

  • seed_2 (Integer) (defaults to: nil) —

    Random seed parameter. Defaults to seed if not set.

  • seed_3 (Integer) (defaults to: nil) —

    Random seed parameter. Defaults to seed if not set.

Returns:



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# File 'lib/polars/series.rb', line 3070

def _hash(seed = 0, seed_1 = nil, seed_2 = nil, seed_3 = nil)
  super
end

#abs ⇒ Series

Compute absolute values.

Returns:



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# File 'lib/polars/series.rb', line 3111

def abs
  super
end

#alias(name) ⇒ Series

Return a copy of the Series with a new alias/name.

Examples:

s = Polars::Series.new("x", [1, 2, 3])
s.alias("y")

Parameters:

  • name (String) —

    New name.

Returns:



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# File 'lib/polars/series.rb', line 783

def alias(name)
  s = dup
  s._s.rename(name)
  s
end

#all ⇒ Boolean

Check if all boolean values in the column are true.

Returns:



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# File 'lib/polars/series.rb', line 361

def all
  to_frame.select(Polars.col(name).all).to_series[0]
end

#any ⇒ Boolean

Check if any boolean value in the column is true.

Returns:



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# File 'lib/polars/series.rb', line 354

def any
  to_frame.select(Polars.col(name).any).to_series[0]
end

#append(other, append_chunks: true) ⇒ Series

Append a Series to this one.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s2 = Polars::Series.new("b", [4, 5, 6])
s.append(s2)
# =>
# shape: (6,)
# Series: 'a' [i64]
# [
#         1
#         2
#         3
#         4
#         5
#         6
# ]

Parameters:

  • other (Series) —

    Series to append.

  • append_chunks (Boolean) (defaults to: true) —

    If set to true the append operation will add the chunks from other to self. This is super cheap.

    If set to false the append operation will do the same as DataFrame#extend which extends the memory backed by this Series with the values from other.

    Different from append_chunks, extend appends the data from other to the underlying memory locations and thus may cause a reallocation (which is expensive).

    If this does not cause a reallocation, the resulting data structure will not have any extra chunks and thus will yield faster queries.

    Prefer extend over append_chunks when you want to do a query after a single append. For instance during online operations where you add n rows and rerun a query.

    Prefer append_chunks over extend when you want to append many times before doing a query. For instance, when you read in multiple files and when to store them in a single Series. In the latter case, finish the sequence of append_chunks operations with a rechunk.

Returns:



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# File 'lib/polars/series.rb', line 1036

def append(other, append_chunks: true)
  begin
    if append_chunks
      _s.append(other._s)
    else
      _s.extend(other._s)
    end
  rescue => e
    if e.message == "Already mutably borrowed"
      append(other.clone, append_chunks)
    else
      raise e
    end
  end
  self
end

#apply(return_dtype: nil, skip_nulls: true, &func) ⇒ Series

Apply a custom/user-defined function (UDF) over elements in this Series and return a new Series.

If the function returns another datatype, the return_dtype arg should be set, otherwise the method will fail.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.apply { |x| x + 10 }
# =>
# shape: (3,)
# Series: 'a' [i64]
# [
#         11
#         12
#         13
# ]

Parameters:

  • return_dtype (Symbol) (defaults to: nil) —

    Output datatype. If none is given, the same datatype as this Series will be used.

  • skip_nulls (Boolean) (defaults to: true) —

    Nulls will be skipped and not passed to the Ruby function. This is faster because Ruby can be skipped and because we call more specialized functions.

Returns:



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# File 'lib/polars/series.rb', line 2371

def apply(return_dtype: nil, skip_nulls: true, &func)
  if return_dtype.nil?
    pl_return_dtype = nil
  else
    pl_return_dtype = Utils.rb_type_to_dtype(return_dtype)
  end
  Utils.wrap_s(_s.apply_lambda(func, pl_return_dtype, skip_nulls))
end

#arccos ⇒ Series

Compute the element-wise value for the inverse cosine.

Examples:

s = Polars::Series.new("a", [1.0, 0.0, -1.0])
s.arccos
# =>
# shape: (3,)
# Series: 'a' [f64]
# [
#         0.0
#         1.570796
#         3.141593
# ]

Returns:



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# File 'lib/polars/series.rb', line 2202

def arccos
  super
end

#arccosh ⇒ Series

Compute the element-wise value for the inverse hyperbolic cosine.

Examples:

s = Polars::Series.new("a", [5.0, 1.0, 0.0, -1.0])
s.arccosh
# =>
# shape: (4,)
# Series: 'a' [f64]
# [
#         2.292432
#         0.0
#         NaN
#         NaN
# ]

Returns:



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# File 'lib/polars/series.rb', line 2260

def arccosh
  super
end

#arcsin ⇒ Series

Compute the element-wise value for the inverse sine.

Examples:

s = Polars::Series.new("a", [1.0, 0.0, -1.0])
s.arcsin
# =>
# shape: (3,)
# Series: 'a' [f64]
# [
#         1.570796
#         0.0
#         -1.570796
# ]

Returns:



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# File 'lib/polars/series.rb', line 2183

def arcsin
  super
end

#arcsinh ⇒ Series

Compute the element-wise value for the inverse hyperbolic sine.

Examples:

s = Polars::Series.new("a", [1.0, 0.0, -1.0])
s.arcsinh
# =>
# shape: (3,)
# Series: 'a' [f64]
# [
#         0.881374
#         0.0
#         -0.881374
# ]

Returns:



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# File 'lib/polars/series.rb', line 2240

def arcsinh
  super
end

#arctan ⇒ Series

Compute the element-wise value for the inverse tangent.

Examples:

s = Polars::Series.new("a", [1.0, 0.0, -1.0])
s.arctan
# =>
# shape: (3,)
# Series: 'a' [f64]
# [
#         0.785398
#         0.0
#         -0.785398
# ]

Returns:



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# File 'lib/polars/series.rb', line 2221

def arctan
  super
end

#arctanh ⇒ Series

Compute the element-wise value for the inverse hyperbolic tangent.

Examples:

s = Polars::Series.new("a", [2.0, 1.0, 0.5, 0.0, -0.5, -1.0, -1.1])
s.arctanh
# =>
# shape: (7,)
# Series: 'a' [f64]
# [
#         NaN
#         inf
#         0.549306
#         0.0
#         -0.549306
#         -inf
#         NaN
# ]

Returns:



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# File 'lib/polars/series.rb', line 2283

def arctanh
  super
end

#arg_max ⇒ Integer?

Get the index of the maximal value.

Examples:

s = Polars::Series.new("a", [3, 2, 1])
s.arg_max
# => 0

Returns:

  • (Integer, nil) 


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# File 'lib/polars/series.rb', line 1271

def arg_max
  _s.arg_max
end

#arg_min ⇒ Integer?

Get the index of the minimal value.

Examples:

s = Polars::Series.new("a", [3, 2, 1])
s.arg_min
# => 2

Returns:

  • (Integer, nil) 


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# File 'lib/polars/series.rb', line 1259

def arg_min
  _s.arg_min
end

#arg_sort(reverse: false, nulls_last: false) ⇒ Series

Get the index values that would sort this Series.

Examples:

s = Polars::Series.new("a", [5, 3, 4, 1, 2])
s.arg_sort
# =>
# shape: (5,)
# Series: 'a' [u32]
# [
#         3
#         4
#         1
#         2
#         0
# ]

Parameters:

  • reverse (Boolean) (defaults to: false) —

    Sort in reverse (descending) order.

  • nulls_last (Boolean) (defaults to: false) —

    Place null values last instead of first.

Returns:



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# File 'lib/polars/series.rb', line 1214

def arg_sort(reverse: false, nulls_last: false)
  super
end

#arg_true ⇒ Series

Get index values where Boolean Series evaluate true.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
(s == 2).arg_true
# =>
# shape: (1,)
# Series: 'a' [u32]
# [
#         1
# ]

Returns:



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# File 'lib/polars/series.rb', line 1541

def arg_true
  Polars.arg_where(self, eager: true)
end

#arg_unique ⇒ Series

Get unique index as Series.

Examples:

s = Polars::Series.new("a", [1, 2, 2, 3])
s.arg_unique
# =>
# shape: (3,)
# Series: 'a' [u32]
# [
#         0
#         1
#         3
# ]

Returns:



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# File 'lib/polars/series.rb', line 1247

def arg_unique
  super
end

#argsort(reverse: false, nulls_last: false) ⇒ Series

Get the index values that would sort this Series.

Alias for #arg_sort.

Parameters:

  • reverse (Boolean) (defaults to: false) —

    Sort in reverse (descending) order.

  • nulls_last (Boolean) (defaults to: false) —

    Place null values last instead of first.

Returns:



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# File 'lib/polars/series.rb', line 1228

def argsort(reverse: false, nulls_last: false)
  super
end

#arr ⇒ ListNameSpace

Create an object namespace of all list related methods.

Returns:



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# File 'lib/polars/series.rb', line 3474

def arr
  ListNameSpace.new(self)
end

#cast(dtype, strict: true) ⇒ Series

Cast between data types.

Examples:

s = Polars::Series.new("a", [true, false, true])
s.cast(:u32)
# =>
# shape: (3,)
# Series: 'a' [u32]
# [
#         1
#         0
#         1
# ]

Parameters:

  • dtype (Symbol) —

    DataType to cast to

  • strict (Boolean) (defaults to: true) —

    Throw an error if a cast could not be done for instance due to an overflow

Returns:



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# File 'lib/polars/series.rb', line 1672

def cast(dtype, strict: true)
  super
end

#cat ⇒ CatNameSpace

Create an object namespace of all categorical related methods.

Returns:



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# File 'lib/polars/series.rb', line 3481

def cat
  CatNameSpace.new(self)
end

#ceil ⇒ Series

Rounds up to the nearest integer value.

Only works on floating point Series.

Examples:

s = Polars::Series.new("a", [1.12345, 2.56789, 3.901234])
s.ceil
# =>
# shape: (3,)
# Series: 'a' [f64]
# [
#         2.0
#         3.0
#         4.0
# ]

Returns:



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# File 'lib/polars/series.rb', line 2022

def ceil
  super
end

#chunk_lengths ⇒ Array

Get the length of each individual chunk.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s2 = Polars::Series.new("b", [4, 5, 6])

Concatenate Series with rechunk: true

Polars.concat([s, s2]).chunk_lengths
# => [6]

Concatenate Series with rechunk: false

Polars.concat([s, s2], rechunk: false).chunk_lengths
# => [3, 3]

Returns:

  • (Array) 


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# File 'lib/polars/series.rb', line 825

def chunk_lengths
  _s.chunk_lengths
end

#cleared ⇒ Series

Create an empty copy of the current Series.

The copy has identical name/dtype but no data.

Examples:

s = Polars::Series.new("a", [nil, true, false])
s.cleared
# =>
# shape: (0,)
# Series: 'a' [bool]
# [
# ]

Returns:



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# File 'lib/polars/series.rb', line 1903

def cleared
  len > 0 ? limit(0) : clone
end

#clip(min_val, max_val) ⇒ Series

Clip (limit) the values in an array to a min and max boundary.

Only works for numerical types.

If you want to clip other dtypes, consider writing a "when, then, otherwise" expression. See LazyFunctions#when for more information.

Examples:

s = Polars::Series.new("foo", [-50, 5, nil, 50])
s.clip(1, 10)
# =>
# shape: (4,)
# Series: 'foo' [i64]
# [
#         1
#         5
#         null
#         10
# ]

Parameters:

  • min_val (Numeric) —

    Minimum value.

  • max_val (Numeric) —

    Maximum value.

Returns:



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# File 'lib/polars/series.rb', line 3295

def clip(min_val, max_val)
  super
end

#clip_max(max_val) ⇒ Series

Clip (limit) the values in an array to a max boundary.

Only works for numerical types.

If you want to clip other dtypes, consider writing a "when, then, otherwise" expression. See LazyFunctions#when for more information.

Parameters:

  • max_val (Numeric) —

    Maximum value.

Returns:



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# File 'lib/polars/series.rb', line 3325

def clip_max(max_val)
  super
end

#clip_min(min_val) ⇒ Series

Clip (limit) the values in an array to a min boundary.

Only works for numerical types.

If you want to clip other dtypes, consider writing a "when, then, otherwise" expression. See LazyFunctions#when for more information.

Parameters:

  • min_val (Numeric) —

    Minimum value.

Returns:



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# File 'lib/polars/series.rb', line 3310

def clip_min(min_val)
  super
end

#cos ⇒ Series

Compute the element-wise value for the cosine.

Examples:

s = Polars::Series.new("a", [0.0, Math::PI / 2.0, Math::PI])
s.cos
# =>
# shape: (3,)
# Series: 'a' [f64]
# [
#         1.0
#         6.1232e-17
#         -1.0
# ]

Returns:



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# File 'lib/polars/series.rb', line 2145

def cos
  super
end

#cosh ⇒ Series

Compute the element-wise value for the hyperbolic cosine.

Examples:

s = Polars::Series.new("a", [1.0, 0.0, -1.0])
s.cosh
# =>
# shape: (3,)
# Series: 'a' [f64]
# [
#         1.543081
#         1.0
#         1.543081
# ]

Returns:



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# File 'lib/polars/series.rb', line 2321

def cosh
  super
end

#cummax(reverse: false) ⇒ Series

Get an array with the cumulative max computed at every element.

Examples:

s = Polars::Series.new("a", [3, 5, 1])
s.cummax
# =>
# shape: (3,)
# Series: 'a' [i64]
# [
#         3
#         5
#         5
# ]

Parameters:

  • reverse (Boolean) (defaults to: false) —

    reverse the operation.

Returns:



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# File 'lib/polars/series.rb', line 914

def cummax(reverse: false)
  super
end

#cummin(reverse: false) ⇒ Series

Get an array with the cumulative min computed at every element.

Examples:

s = Polars::Series.new("a", [3, 5, 1])
s.cummin
# =>
# shape: (3,)
# Series: 'a' [i64]
# [
#         3
#         3
#         1
# ]

Parameters:

  • reverse (Boolean) (defaults to: false) —

    reverse the operation.

Returns:



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# File 'lib/polars/series.rb', line 892

def cummin(reverse: false)
  super
end

#cumprod(reverse: false) ⇒ Series

Note:

Dtypes :i8, :u8, :i16, and :u16 are cast to :i64 before multiplying to prevent overflow issues.

Get an array with the cumulative product computed at every element.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.cumprod
# =>
# shape: (3,)
# Series: 'a' [i64]
# [
#         1
#         2
#         6
# ]

Parameters:

  • reverse (Boolean) (defaults to: false) —

    reverse the operation.

Returns:



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# File 'lib/polars/series.rb', line 940

def cumprod(reverse: false)
  super
end

#cumsum(reverse: false) ⇒ Series

Note:

Dtypes :i8, :u8, :i16, and :u16 are cast to :i64 before summing to prevent overflow issues.

Get an array with the cumulative sum computed at every element.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.cumsum
# =>
# shape: (3,)
# Series: 'a' [i64]
# [
#         1
#         3
#         6
# ]

Parameters:

  • reverse (Boolean) (defaults to: false) —

    reverse the operation.

Returns:



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# File 'lib/polars/series.rb', line 870

def cumsum(reverse: false)
  super
end

#cumulative_eval(expr, min_periods: 1, parallel: false) ⇒ Series

Note:

This functionality is experimental and may change without it being considered a breaking change.

Note:

This can be really slow as it can have O(n^2) complexity. Don't use this for operations that visit all elements.

Run an expression over a sliding window that increases 1 slot every iteration.

Examples:

s = Polars::Series.new("values", [1, 2, 3, 4, 5])
s.cumulative_eval(Polars.element.first - Polars.element.last ** 2)
# =>
# shape: (5,)
# Series: 'values' [f64]
# [
#         0.0
#         -3.0
#         -8.0
#         -15.0
#         -24.0
# ]

Parameters:

  • expr (Expr) —

    Expression to evaluate

  • min_periods (Integer) (defaults to: 1) —

    Number of valid values there should be in the window before the expression is evaluated. valid values = length - null_count

  • parallel (Boolean) (defaults to: false) —

    Run in parallel. Don't do this in a groupby or another operation that already has much parallelization.

Returns:



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# File 'lib/polars/series.rb', line 769

def cumulative_eval(expr, min_periods: 1, parallel: false)
  super
end

#describe ⇒ DataFrame

Quick summary statistics of a series.

Series with mixed datatypes will return summary statistics for the datatype of the first value.

Examples:

series_num = Polars::Series.new([1, 2, 3, 4, 5])
series_num.describe
# =>
# shape: (6, 2)
# ┌────────────┬──────────┐
# │ statistic  ┆ value    │
# │ ---        ┆ ---      │
# │ str        ┆ f64      │
# ╞════════════╪══════════╡
# │ min        ┆ 1.0      │
# ├╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌┤
# │ max        ┆ 5.0      │
# ├╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌┤
# │ null_count ┆ 0.0      │
# ├╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌┤
# │ mean       ┆ 3.0      │
# ├╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌┤
# │ std        ┆ 1.581139 │
# ├╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌┤
# │ count      ┆ 5.0      │
# └────────────┴──────────┘

series_str = Polars::Series.new(["a", "a", nil, "b", "c"])
series_str.describe
# =>
# shape: (3, 2)
# ┌────────────┬───────┐
# │ statistic  ┆ value │
# │ ---        ┆ ---   │
# │ str        ┆ i64   │
# ╞════════════╪═══════╡
# │ unique     ┆ 4     │
# ├╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┤
# │ null_count ┆ 1     │
# ├╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┤
# │ count      ┆ 5     │
# └────────────┴───────┘

Returns:



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# File 'lib/polars/series.rb', line 456

def describe
  if len == 0
    raise ArgumentError, "Series must contain at least one value"
  elsif is_numeric
    s = cast(:f64)
    stats = {
      "min" => s.min,
      "max" => s.max,
      "null_count" => s.null_count,
      "mean" => s.mean,
      "std" => s.std,
      "count" => s.len
    }
  elsif is_boolean
    stats = {
      "sum" => sum,
      "null_count" => null_count,
      "count" => len
    }
  elsif is_utf8
    stats = {
      "unique" => unique.length,
      "null_count" => null_count,
      "count" => len
    }
  elsif is_datelike
    # we coerce all to string, because a polars column
    # only has a single dtype and dates: datetime and count: int don't match
    stats = {
      "min" => dt.min.to_s,
      "max" => dt.max.to_s,
      "null_count" => null_count.to_s,
      "count" => len.to_s
    }
  else
    raise TypeError, "This type is not supported"
  end

  Polars::DataFrame.new(
    {"statistic" => stats.keys, "value" => stats.values}
  )
end

#diff(n: 1, null_behavior: "ignore") ⇒ Series

Calculate the n-th discrete difference.

Parameters:

  • n (Integer) (defaults to: 1) —

    Number of slots to shift.

  • null_behavior ("ignore", "drop") (defaults to: "ignore") —

    How to handle null values.

Returns:



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# File 'lib/polars/series.rb', line 3179

def diff(n: 1, null_behavior: "ignore")
  super
end

#dot(other) ⇒ Numeric

Compute the dot/inner product between two Series.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s2 = Polars::Series.new("b", [4.0, 5.0, 6.0])
s.dot(s2)
# => 32.0

Parameters:

  • other (Object) —

    Series (or array) to compute dot product with.

Returns:

  • (Numeric) 


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# File 'lib/polars/series.rb', line 2060

def dot(other)
  if !other.is_a?(Series)
    other = Series.new(other)
  end
  if len != other.len
    n, m = len, other.len
    raise ArgumentError, "Series length mismatch: expected #{n}, found #{m}"
  end
  _s.dot(other._s)
end

#drop_nans ⇒ Series

Drop NaN values.

Returns:



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# File 'lib/polars/series.rb', line 399

def drop_nans
  super
end

#drop_nulls ⇒ Series

Create a new Series that copies data from this Series without null values.

Returns:



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# File 'lib/polars/series.rb', line 392

def drop_nulls
  super
end

#dt ⇒ DateTimeNameSpace

Create an object namespace of all datetime related methods.

Returns:



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# File 'lib/polars/series.rb', line 3488

def dt
  DateTimeNameSpace.new(self)
end

#dtype ⇒ Symbol

Get the data type of this Series.

Returns:

  • (Symbol) 


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# File 'lib/polars/series.rb', line 85

def dtype
  _s.dtype
end

#entropy(base: Math::E, normalize: false) ⇒ Float?

Computes the entropy.

Uses the formula -sum(pk * log(pk) where pk are discrete probabilities.

Examples:

a = Polars::Series.new([0.99, 0.005, 0.005])
a.entropy(normalize: true)
# => 0.06293300616044681

b = Polars::Series.new([0.65, 0.10, 0.25])
b.entropy(normalize: true)
# => 0.8568409950394724

Parameters:

  • base (Float) (defaults to: Math::E) —

    Given base, defaults to e

  • normalize (Boolean) (defaults to: false) —

    Normalize pk if it doesn't sum to 1.

Returns:

  • (Float, nil) 


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# File 'lib/polars/series.rb', line 731

def entropy(base: Math::E, normalize: false)
  Polars.select(Polars.lit(self).entropy(base: base, normalize: normalize)).to_series[0]
end

#estimated_size(unit = "b") ⇒ Numeric

Return an estimation of the total (heap) allocated size of the Series.

Estimated size is given in the specified unit (bytes by default).

This estimation is the sum of the size of its buffers, validity, including nested arrays. Multiple arrays may share buffers and bitmaps. Therefore, the size of 2 arrays is not the sum of the sizes computed from this function. In particular, StructArray's size is an upper bound.

When an array is sliced, its allocated size remains constant because the buffer unchanged. However, this function will yield a smaller number. This is because this function returns the visible size of the buffer, not its total capacity.

FFI buffers are included in this estimation.

Examples:

s = Polars::Series.new("values", 1..1_000_000, dtype: :u32)
s.estimated_size
# => 4000000
s.estimated_size("mb")
# => 3.814697265625

Parameters:

  • unit ("b", "kb", "mb", "gb", "tb") (defaults to: "b") —

    Scale the returned size to the given unit.

Returns:

  • (Numeric) 


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# File 'lib/polars/series.rb', line 339

def estimated_size(unit = "b")
  sz = _s.estimated_size
  Utils.scale_bytes(sz, to: unit)
end

#ewm_mean(com: nil, span: nil, half_life: nil, alpha: nil, adjust: true, min_periods: 1) ⇒ Series

Exponentially-weighted moving average.

Returns:



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# File 'lib/polars/series.rb', line 3365

def ewm_mean(
  com: nil,
  span: nil,
  half_life: nil,
  alpha: nil,
  adjust: true,
  min_periods: 1
)
  super
end

#ewm_std(com: nil, span: nil, half_life: nil, alpha: nil, adjust: true, bias: false, min_periods: 1) ⇒ Series

Exponentially-weighted moving standard deviation.

Returns:



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# File 'lib/polars/series.rb', line 3379

def ewm_std(
  com: nil,
  span: nil,
  half_life: nil,
  alpha: nil,
  adjust: true,
  bias: false,
  min_periods: 1
)
  super
end

#ewm_var(com: nil, span: nil, half_life: nil, alpha: nil, adjust: true, bias: false, min_periods: 1) ⇒ Series

Exponentially-weighted moving variance.

Returns:



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# File 'lib/polars/series.rb', line 3394

def ewm_var(
  com: nil,
  span: nil,
  half_life: nil,
  alpha: nil,
  adjust: true,
  bias: false,
  min_periods: 1
)
  super
end

#exp ⇒ Series

Compute the exponential, element-wise.

Returns:



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# File 'lib/polars/series.rb', line 385

def exp
  super
end

#explode ⇒ Series

Explode a list or utf8 Series.

This means that every item is expanded to a new row.

Examples:

s = Polars::Series.new("a", [[1, 2], [3, 4], [9, 10]])
s.explode
# =>
# shape: (6,)
# Series: 'a' [i64]
# [
#         1
#         2
#         3
#         4
#         9
#         10
# ]

Returns:



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# File 'lib/polars/series.rb', line 1612

def explode
  super
end

#extend_constant(value, n) ⇒ Series

Extend the Series with given number of values.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.extend_constant(99, 2)
# =>
# shape: (5,)
# Series: 'a' [i64]
# [
#         1
#         2
#         3
#         99
#         99
# ]

Parameters:

  • value (Object) —

    The value to extend the Series with. This value may be nil to fill with nulls.

  • n (Integer) —

    The number of values to extend.

Returns:



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# File 'lib/polars/series.rb', line 3429

def extend_constant(value, n)
  super
end

#fill_nan(fill_value) ⇒ Series

Fill floating point NaN value with a fill value.

Examples:

s = Polars::Series.new("a", [1.0, 2.0, 3.0, Float::NAN])
s.fill_nan(0)
# =>
# shape: (4,)
# Series: 'a' [f64]
# [
#         1.0
#         2.0
#         3.0
#         0.0
# ]

Parameters:

  • fill_value (Object) —

    Value used to fill nan values.

Returns:



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# File 'lib/polars/series.rb', line 1928

def fill_nan(fill_value)
  super
end

#fill_null(value = nil, strategy: nil, limit: nil) ⇒ Series

Fill null values using the specified value or strategy.

Examples:

s = Polars::Series.new("a", [1, 2, 3, nil])
s.fill_null(strategy: "forward")
# =>
# shape: (4,)
# Series: 'a' [i64]
# [
#         1
#         2
#         3
#         3
# ]

s.fill_null(strategy: "min")
# =>
# shape: (4,)
# Series: 'a' [i64]
# [
#         1
#         2
#         3
#         1
# ]

s = Polars::Series.new("b", ["x", nil, "z"])
s.fill_null(Polars.lit(""))
# =>
# shape: (3,)
# Series: 'b' [str]
# [
#         "x"
#         ""
#         "z"
# ]

Parameters:

  • value (Object) (defaults to: nil) —

    Value used to fill null values.

  • strategy (nil, "forward", "backward", "min", "max", "mean", "zero", "one") (defaults to: nil) —

    Strategy used to fill null values.

  • limit (defaults to: nil) —

    Number of consecutive null values to fill when using the "forward" or "backward" strategy.

Returns:



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# File 'lib/polars/series.rb', line 1980

def fill_null(value = nil, strategy: nil, limit: nil)
  super
end

#filter(predicate) ⇒ Series

Filter elements by a boolean mask.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
mask = Polars::Series.new("", [true, false, true])
s.filter(mask)
# =>
# shape: (2,)
# Series: 'a' [i64]
# [
#         1
#         3
# ]

Parameters:

  • predicate (Series, Array) —

    Boolean mask.

Returns:



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# File 'lib/polars/series.rb', line 1071

def filter(predicate)
  if predicate.is_a?(Array)
    predicate = Series.new("", predicate)
  end
  Utils.wrap_s(_s.filter(predicate._s))
end

#flags ⇒ Hash

Get flags that are set on the Series.

Returns:

  • (Hash) 


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# File 'lib/polars/series.rb', line 92

def flags
  {
    "SORTED_ASC" => _s.is_sorted_flag,
    "SORTED_DESC" => _s.is_sorted_reverse_flag
  }
end

#floor ⇒ Series

Rounds down to the nearest integer value.

Only works on floating point Series.

Examples:

s = Polars::Series.new("a", [1.12345, 2.56789, 3.901234])
s.floor
# =>
# shape: (3,)
# Series: 'a' [f64]
# [
#         1.0
#         2.0
#         3.0
# ]

Returns:



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# File 'lib/polars/series.rb', line 2001

def floor
  Utils.wrap_s(_s.floor)
end

#has_validity ⇒ Boolean

Return true if the Series has a validity bitmask.

If there is none, it means that there are no null values. Use this to swiftly assert a Series does not have null values.

Returns:



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# File 'lib/polars/series.rb', line 1341

def has_validity
  _s.has_validity
end

#head(n = 10) ⇒ Series

Get the first n rows.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.head(2)
# =>
# shape: (2,)
# Series: 'a' [i64]
# [
#         1
#         2
# ]

Parameters:

  • n (Integer) (defaults to: 10) —

    Number of rows to return.

Returns:



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# File 'lib/polars/series.rb', line 1095

def head(n = 10)
  to_frame.select(Utils.col(name).head(n)).to_series
end

#inner_dtype ⇒ Symbol

Get the inner dtype in of a List typed Series.

Returns:

  • (Symbol) 


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# File 'lib/polars/series.rb', line 102

def inner_dtype
  _s.inner_dtype
end

#interpolate(method: "linear") ⇒ Series

Interpolate intermediate values. The interpolation method is linear.

Examples:

s = Polars::Series.new("a", [1, 2, nil, nil, 5])
s.interpolate
# =>
# shape: (5,)
# Series: 'a' [i64]
# [
#         1
#         2
#         3
#         4
#         5
# ]

Returns:



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# File 'lib/polars/series.rb', line 3104

def interpolate(method: "linear")
  super
end

#is_boolean ⇒ Boolean Also known as: boolean?, is_bool, bool?

Check if this Series is a Boolean.

Examples:

s = Polars::Series.new("a", [true, false, true])
s.is_boolean
# => true

Returns:



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# File 'lib/polars/series.rb', line 1791

def is_boolean
  dtype == Boolean
end

#is_datelike ⇒ Boolean

Check if this Series datatype is datelike.

Examples:

s = Polars::Series.new([Date.new(2021, 1, 1), Date.new(2021, 1, 2), Date.new(2021, 1, 3)])
s.is_datelike
# => true

Returns:



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# File 'lib/polars/series.rb', line 1766

def is_datelike
  [Date, Datetime, Duration, Time].include?(dtype)
end

#is_duplicated ⇒ Series

Get mask of all duplicated values.

Examples:

s = Polars::Series.new("a", [1, 2, 2, 3])
s.is_duplicated
# =>
# shape: (4,)
# Series: 'a' [bool]
# [
#         false
#         true
#         true
#         false
# ]

Returns:



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# File 'lib/polars/series.rb', line 1588

def is_duplicated
  super
end

#is_empty ⇒ Boolean Also known as: empty?

Check if the Series is empty.

Examples:

s = Polars::Series.new("a", [])
s.is_empty
# => true

Returns:



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# File 'lib/polars/series.rb', line 1353

def is_empty
  len == 0
end

#is_finite ⇒ Series

Returns a boolean Series indicating which values are finite.

Examples:

s = Polars::Series.new("a", [1.0, 2.0, Float::INFINITY])
s.is_finite
# =>
# shape: (3,)
# Series: 'a' [bool]
# [
#         true
#         true
#         false
# ]

Returns:



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# File 'lib/polars/series.rb', line 1413

def is_finite
  super
end

#is_first ⇒ Series

Get a mask of the first unique value.

Returns:



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# File 'lib/polars/series.rb', line 1568

def is_first
  super
end

#is_float ⇒ Boolean Also known as: float?

Check if this Series has floating point numbers.

Examples:

s = Polars::Series.new("a", [1.0, 2.0, 3.0])
s.is_float
# => true

Returns:



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# File 'lib/polars/series.rb', line 1778

def is_float
  [Float32, Float64].include?(dtype)
end

#is_in(other) ⇒ Series

Check if elements of this Series are in the other Series.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s2 = Polars::Series.new("b", [2, 4])
s2.is_in(s)
# =>
# shape: (2,)
# Series: 'b' [bool]
# [
#         true
#         false
# ]

sets = Polars::Series.new("sets", [[1, 2, 3], [1, 2], [9, 10]])
# =>
# shape: (3,)
# Series: 'sets' [list]
# [
#         [1, 2, 3]
#         [1, 2]
#         [9, 10]
# ]

optional_members = Polars::Series.new("optional_members", [1, 2, 3])
# =>
# shape: (3,)
# Series: 'optional_members' [i64]
# [
#         1
#         2
#         3
# ]

optional_members.is_in(sets)
# =>
# shape: (3,)
# Series: 'optional_members' [bool]
# [
#         true
#         true
#         false
# ]

Returns:



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# File 'lib/polars/series.rb', line 1524

def is_in(other)
  super
end

#is_infinite ⇒ Series

Returns a boolean Series indicating which values are infinite.

Examples:

s = Polars::Series.new("a", [1.0, 2.0, Float::INFINITY])
s.is_infinite
# =>
# shape: (3,)
# Series: 'a' [bool]
# [
#         false
#         false
#         true
# ]

Returns:



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# File 'lib/polars/series.rb', line 1432

def is_infinite
  super
end

#is_nan ⇒ Series

Returns a boolean Series indicating which values are NaN.

Examples:

s = Polars::Series.new("a", [1.0, 2.0, 3.0, Float::NAN])
s.is_nan
# =>
# shape: (4,)
# Series: 'a' [bool]
# [
#         false
#         false
#         false
#         true
# ]

Returns:



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# File 'lib/polars/series.rb', line 1452

def is_nan
  super
end

#is_not_nan ⇒ Series

Returns a boolean Series indicating which values are not NaN.

Examples:

s = Polars::Series.new("a", [1.0, 2.0, 3.0, Float::NAN])
s.is_not_nan
# =>
# shape: (4,)
# Series: 'a' [bool]
# [
#         true
#         true
#         true
#         false
# ]

Returns:



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# File 'lib/polars/series.rb', line 1472

def is_not_nan
  super
end

#is_not_null ⇒ Series

Returns a boolean Series indicating which values are not null.

Examples:

s = Polars::Series.new("a", [1.0, 2.0, 3.0, nil])
s.is_not_null
# =>
# shape: (4,)
# Series: 'a' [bool]
# [
#         true
#         true
#         true
#         false
# ]

Returns:



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# File 'lib/polars/series.rb', line 1394

def is_not_null
  super
end

#is_null ⇒ Series

Returns a boolean Series indicating which values are null.

Examples:

s = Polars::Series.new("a", [1.0, 2.0, 3.0, nil])
s.is_null
# =>
# shape: (4,)
# Series: 'a' [bool]
# [
#         false
#         false
#         false
#         true
# ]

Returns:



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# File 'lib/polars/series.rb', line 1374

def is_null
  super
end

#is_numeric ⇒ Boolean Also known as: numeric?

Check if this Series datatype is numeric.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.is_numeric
# => true

Returns:



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# File 'lib/polars/series.rb', line 1753

def is_numeric
  [Int8, Int16, Int32, Int64, UInt8, UInt16, UInt32, UInt64, Float32, Float64].include?(dtype)
end

#is_unique ⇒ Series

Get mask of all unique values.

Examples:

s = Polars::Series.new("a", [1, 2, 2, 3])
s.is_unique
# =>
# shape: (4,)
# Series: 'a' [bool]
# [
#         true
#         false
#         false
#         true
# ]

Returns:



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# File 'lib/polars/series.rb', line 1561

def is_unique
  super
end

#is_utf8 ⇒ Boolean Also known as: utf8?

Check if this Series datatype is a Utf8.

Examples:

s = Polars::Series.new("x", ["a", "b", "c"])
s.is_utf8
# => true

Returns:



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# File 'lib/polars/series.rb', line 1806

def is_utf8
  dtype == Utf8
end

#kurtosis(fisher: true, bias: true) ⇒ Float?

Compute the kurtosis (Fisher or Pearson) of a dataset.

Kurtosis is the fourth central moment divided by the square of the variance. If Fisher's definition is used, then 3.0 is subtracted from the result to give 0.0 for a normal distribution. If bias is false, then the kurtosis is calculated using k statistics to eliminate bias coming from biased moment estimators

Parameters:

  • fisher (Boolean) (defaults to: true) —

    If true, Fisher's definition is used (normal ==> 0.0). If false, Pearson's definition is used (normal ==> 3.0).

  • bias (Boolean) (defaults to: true) —

    If false, the calculations are corrected for statistical bias.

Returns:

  • (Float, nil) 


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# File 'lib/polars/series.rb', line 3265

def kurtosis(fisher: true, bias: true)
  _s.kurtosis(fisher, bias)
end

#len ⇒ Integer Also known as: length

Length of this Series.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.len
# => 3

Returns:

  • (Integer) 


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# File 'lib/polars/series.rb', line 1647

def len
  _s.len
end

#limit(n = 10) ⇒ Series

Get the first n rows.

Alias for #head.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.limit(2)
# =>
# shape: (2,)
# Series: 'a' [i64]
# [
#         1
#         2
# ]

Parameters:

  • n (Integer) (defaults to: 10) —

    Number of rows to return.

Returns:



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# File 'lib/polars/series.rb', line 963

def limit(n = 10)
  to_frame.select(Utils.col(name).limit(n)).to_series
end

#log(base = Math::E) ⇒ Series

Compute the logarithm to a given base.

Parameters:

  • base (Float) (defaults to: Math::E) —

    Given base, defaults to Math::E.

Returns:



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# File 'lib/polars/series.rb', line 371

def log(base = Math::E)
  super
end

#log10 ⇒ Series

Compute the base 10 logarithm of the input array, element-wise.

Returns:



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# File 'lib/polars/series.rb', line 378

def log10
  super
end

#max ⇒ Object

Get the maximum value in this Series.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.max
# => 3

Returns:



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# File 'lib/polars/series.rb', line 554

def max
  _s.max
end

#mean ⇒ Float?

Reduce this Series to the mean value.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.mean
# => 2.0

Returns:

  • (Float, nil) 


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# File 'lib/polars/series.rb', line 523

def mean
  _s.mean
end

#median ⇒ Float?

Get the median of this Series.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.median
# => 2.0

Returns:

  • (Float, nil) 


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# File 'lib/polars/series.rb', line 620

def median
  _s.median
end

#min ⇒ Object

Get the minimal value in this Series.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.min
# => 1

Returns:



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# File 'lib/polars/series.rb', line 542

def min
  _s.min
end

#mode ⇒ Series

Compute the most occurring value(s).

Can return multiple Values.

Examples:

s = Polars::Series.new("a", [1, 2, 2, 3])
s.mode
# =>
# shape: (1,)
# Series: 'a' [i64]
# [
#         2
# ]

Returns:



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# File 'lib/polars/series.rb', line 2086

def mode
  super
end

#n_chunks ⇒ Integer

Get the number of chunks that this Series contains.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s2 = Polars::Series.new("b", [4, 5, 6])

Concatenate Series with rechunk: true

Polars.concat([s, s2]).n_chunks
# => 1

Concatenate Series with rechunk: false

Polars.concat([s, s2], rechunk: false).n_chunks
# => 2

Returns:

  • (Integer) 


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# File 'lib/polars/series.rb', line 844

def n_chunks
  _s.n_chunks
end

#n_unique ⇒ Integer

Count the number of unique values in this Series.

Examples:

s = Polars::Series.new("a", [1, 2, 2, 3])
s.n_unique
# => 3

Returns:

  • (Integer) 


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# File 'lib/polars/series.rb', line 3023

def n_unique
  _s.n_unique
end

#name ⇒ String

Get the name of this Series.

Returns:

  • (String) 


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# File 'lib/polars/series.rb', line 109

def name
  _s.name
end

#nan_max ⇒ Object

Get maximum value, but propagate/poison encountered NaN values.

Returns:



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# File 'lib/polars/series.rb', line 561

def nan_max
  to_frame.select(Polars.col(name).nan_max)[0, 0]
end

#nan_min ⇒ Object

Get minimum value, but propagate/poison encountered NaN values.

Returns:



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# File 'lib/polars/series.rb', line 568

def nan_min
  to_frame.select(Polars.col(name).nan_min)[0, 0]
end

#new_from_index(index, length) ⇒ Series

Create a new Series filled with values from the given index.

Returns:



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# File 'lib/polars/series.rb', line 3457

def new_from_index(index, length)
  Utils.wrap_s(_s.new_from_index(index, length))
end

#null_count ⇒ Integer

Count the null values in this Series.

Returns:

  • (Integer) 


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# File 'lib/polars/series.rb', line 1331

def null_count
  _s.null_count
end

#pct_change(n: 1) ⇒ Series

Computes percentage change between values.

Percentage change (as fraction) between current element and most-recent non-null element at least n period(s) before the current element.

Computes the change from the previous row by default.

Examples:

Polars::Series.new(0..9).pct_change
# =>
# shape: (10,)
# Series: '' [f64]
# [
#         null
#         inf
#         1.0
#         0.5
#         0.333333
#         0.25
#         0.2
#         0.166667
#         0.142857
#         0.125
# ]

Polars::Series.new([1, 2, 4, 8, 16, 32, 64, 128, 256, 512]).pct_change(n: 2)
# =>
# shape: (10,)
# Series: '' [f64]
# [
#         null
#         null
#         3.0
#         3.0
#         3.0
#         3.0
#         3.0
#         3.0
#         3.0
#         3.0
# ]

Parameters:

  • n (Integer) (defaults to: 1) —

    periods to shift for forming percent change.

Returns:



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# File 'lib/polars/series.rb', line 3230

def pct_change(n: 1)
  super
end

#peak_max ⇒ Series

Get a boolean mask of the local maximum peaks.

Examples:

s = Polars::Series.new("a", [1, 2, 3, 4, 5])
s.peak_max
# =>
# shape: (5,)
# Series: '' [bool]
# [
#         false
#         false
#         false
#         false
#         true
# ]

Returns:



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# File 'lib/polars/series.rb', line 2990

def peak_max
  Utils.wrap_s(_s.peak_max)
end

#peak_min ⇒ Series

Get a boolean mask of the local minimum peaks.

Examples:

s = Polars::Series.new("a", [4, 1, 3, 2, 5])
s.peak_min
# =>
# shape: (5,)
# Series: '' [bool]
# [
#         false
#         true
#         false
#         true
#         false
# ]

Returns:



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# File 'lib/polars/series.rb', line 3011

def peak_min
  Utils.wrap_s(_s.peak_min)
end

#product ⇒ Numeric

Reduce this Series to the product value.

Returns:

  • (Numeric) 


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# File 'lib/polars/series.rb', line 530

def product
  to_frame.select(Polars.col(name).product).to_series[0]
end

#quantile(quantile, interpolation: "nearest") ⇒ Float?

Get the quantile value of this Series.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.quantile(0.5)
# => 2.0

Parameters:

  • quantile (Float, nil) —

    Quantile between 0.0 and 1.0.

  • interpolation ("nearest", "higher", "lower", "midpoint", "linear") (defaults to: "nearest") —

    Interpolation method.

Returns:

  • (Float, nil) 


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# File 'lib/polars/series.rb', line 637

def quantile(quantile, interpolation: "nearest")
  _s.quantile(quantile, interpolation)
end

#rank(method: "average", reverse: false) ⇒ Series

Assign ranks to data, dealing with ties appropriately.

Examples:

The 'average' method:

s = Polars::Series.new("a", [3, 6, 1, 1, 6])
s.rank
# =>
# shape: (5,)
# Series: 'a' [f32]
# [
#         3.0
#         4.5
#         1.5
#         1.5
#         4.5
# ]

The 'ordinal' method:

s = Polars::Series.new("a", [3, 6, 1, 1, 6])
s.rank(method: "ordinal")
# =>
# shape: (5,)
# Series: 'a' [u32]
# [
#         3
#         4
#         1
#         2
#         5
# ]

Parameters:

  • method ("average", "min", "max", "dense", "ordinal", "random") (defaults to: "average") —

    The method used to assign ranks to tied elements. The following methods are available (default is 'average'):

    • 'average' : The average of the ranks that would have been assigned to all the tied values is assigned to each value.
    • 'min' : The minimum of the ranks that would have been assigned to all the tied values is assigned to each value. (This is also referred to as "competition" ranking.)
    • 'max' : The maximum of the ranks that would have been assigned to all the tied values is assigned to each value.
    • 'dense' : Like 'min', but the rank of the next highest element is assigned the rank immediately after those assigned to the tied elements.
    • 'ordinal' : All values are given a distinct rank, corresponding to the order that the values occur in the Series.
    • 'random' : Like 'ordinal', but the rank for ties is not dependent on the order that the values occur in the Series.
  • reverse (Boolean) (defaults to: false) —

    Reverse the operation.

Returns:



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# File 'lib/polars/series.rb', line 3167

def rank(method: "average", reverse: false)
  super
end

#rechunk(in_place: false) ⇒ Series

Create a single chunk of memory for this Series.

Parameters:

  • in_place (Boolean) (defaults to: false) —

    In place or not.

Returns:



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# File 'lib/polars/series.rb', line 1721

def rechunk(in_place: false)
  opt_s = _s.rechunk(in_place)
  in_place ? self : Utils.wrap_s(opt_s)
end

#reinterpret(signed: true) ⇒ Series

Reinterpret the underlying bits as a signed/unsigned integer.

This operation is only allowed for 64bit integers. For lower bits integers, you can safely use that cast operation.

Parameters:

  • signed (Boolean) (defaults to: true) —

    If true, reinterpret as :i64. Otherwise, reinterpret as :u64.

Returns:



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# File 'lib/polars/series.rb', line 3083

def reinterpret(signed: true)
  super
end

#rename(name, in_place: false) ⇒ Series

Rename this Series.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.rename("b")

Parameters:

  • name (String) —

    New name.

  • in_place (Boolean) (defaults to: false) —

    Modify the Series in-place.

Returns:



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# File 'lib/polars/series.rb', line 801

def rename(name, in_place: false)
  if in_place
    _s.rename(name)
    self
  else
    self.alias(name)
  end
end

#reshape(dims) ⇒ Series

Reshape this Series to a flat Series or a Series of Lists.

Parameters:

  • dims (Array) —

    Tuple of the dimension sizes. If a -1 is used in any of the dimensions, that dimension is inferred.

Returns:



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# File 'lib/polars/series.rb', line 3336

def reshape(dims)
  super
end

#reverse ⇒ Series

Return Series in reverse order.

Examples:

s = Polars::Series.new("a", [1, 2, 3], dtype: :i8)
s.reverse
# =>
# shape: (3,)
# Series: 'a' [i8]
# [
#         3
#         2
#         1
# ]

Returns:



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# File 'lib/polars/series.rb', line 1741

def reverse
  super
end

#rolling_max(window_size, weights: nil, min_periods: nil, center: false) ⇒ Series

Apply a rolling max (moving max) over the values in this array.

A window of length window_size will traverse the array. The values that fill this window will (optionally) be multiplied with the weights given by the weight vector. The resulting values will be aggregated to their sum.

Examples:

s = Polars::Series.new("a", [100, 200, 300, 400, 500])
s.rolling_max(2)
# =>
# shape: (5,)
# Series: 'a' [i64]
# [
#         null
#         200
#         300
#         400
#         500
# ]

Parameters:

  • window_size (Integer) —

    The length of the window.

  • weights (Array) (defaults to: nil) —

    An optional slice with the same length as the window that will be multiplied elementwise with the values in the window.

  • min_periods (Integer) (defaults to: nil) —

    The number of values in the window that should be non-null before computing a result. If None, it will be set equal to window size.

  • center (Boolean) (defaults to: false) —

    Set the labels at the center of the window

Returns:



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# File 'lib/polars/series.rb', line 2551

def rolling_max(
  window_size,
  weights: nil,
  min_periods: nil,
  center: false
)
  to_frame
    .select(
      Polars.col(name).rolling_max(
        window_size,
        weights: weights,
        min_periods: min_periods,
        center: center
      )
    )
    .to_series
end

#rolling_mean(window_size, weights: nil, min_periods: nil, center: false) ⇒ Series

Apply a rolling mean (moving mean) over the values in this array.

A window of length window_size will traverse the array. The values that fill this window will (optionally) be multiplied with the weights given by the weight vector. The resulting values will be aggregated to their sum.

Examples:

s = Polars::Series.new("a", [100, 200, 300, 400, 500])
s.rolling_mean(2)
# =>
# shape: (5,)
# Series: 'a' [f64]
# [
#         null
#         150.0
#         250.0
#         350.0
#         450.0
# ]

Parameters:

  • window_size (Integer) —

    The length of the window.

  • weights (Array) (defaults to: nil) —

    An optional slice with the same length as the window that will be multiplied elementwise with the values in the window.

  • min_periods (Integer) (defaults to: nil) —

    The number of values in the window that should be non-null before computing a result. If None, it will be set equal to window size.

  • center (Boolean) (defaults to: false) —

    Set the labels at the center of the window

Returns:



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# File 'lib/polars/series.rb', line 2601

def rolling_mean(
  window_size,
  weights: nil,
  min_periods: nil,
  center: false
)
  to_frame
    .select(
      Polars.col(name).rolling_mean(
        window_size,
        weights: weights,
        min_periods: min_periods,
        center: center
      )
    )
    .to_series
end

#rolling_median(window_size, weights: nil, min_periods: nil, center: false) ⇒ Series

Compute a rolling median.

Examples:

s = Polars::Series.new("a", [1.0, 2.0, 3.0, 4.0, 6.0, 8.0])
s.rolling_median(3)
# =>
# shape: (6,)
# Series: 'a' [f64]
# [
#         null
#         null
#         2.0
#         3.0
#         4.0
#         6.0
# ]

Parameters:

  • window_size (Integer) —

    The length of the window.

  • weights (Array) (defaults to: nil) —

    An optional slice with the same length as the window that will be multiplied elementwise with the values in the window.

  • min_periods (Integer) (defaults to: nil) —

    The number of values in the window that should be non-null before computing a result. If None, it will be set equal to window size.

  • center (Boolean) (defaults to: false) —

    Set the labels at the center of the window

Returns:



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# File 'lib/polars/series.rb', line 2803

def rolling_median(
  window_size,
  weights: nil,
  min_periods: nil,
  center: false
)
  if min_periods.nil?
    min_periods = window_size
  end

  to_frame
    .select(
      Polars.col(name).rolling_median(
        window_size,
        weights: weights,
        min_periods: min_periods,
        center: center
      )
    )
    .to_series
end

#rolling_min(window_size, weights: nil, min_periods: nil, center: false) ⇒ Series

Apply a rolling min (moving min) over the values in this array.

A window of length window_size will traverse the array. The values that fill this window will (optionally) be multiplied with the weights given by the weight vector. The resulting values will be aggregated to their sum.

Examples:

s = Polars::Series.new("a", [100, 200, 300, 400, 500])
s.rolling_min(3)
# =>
# shape: (5,)
# Series: 'a' [i64]
# [
#         null
#         null
#         100
#         200
#         300
# ]

Parameters:

  • window_size (Integer) —

    The length of the window.

  • weights (Array) (defaults to: nil) —

    An optional slice with the same length as the window that will be multiplied elementwise with the values in the window.

  • min_periods (Integer) (defaults to: nil) —

    The number of values in the window that should be non-null before computing a result. If None, it will be set equal to window size.

  • center (Boolean) (defaults to: false) —

    Set the labels at the center of the window

Returns:



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# File 'lib/polars/series.rb', line 2501

def rolling_min(
  window_size,
  weights: nil,
  min_periods: nil,
  center: false
)
  to_frame
    .select(
      Polars.col(name).rolling_min(
        window_size,
        weights: weights,
        min_periods: min_periods,
        center: center
      )
    )
    .to_series
end

#rolling_quantile(quantile, interpolation: "nearest", window_size: 2, weights: nil, min_periods: nil, center: false) ⇒ Series

Compute a rolling quantile.

Examples:

s = Polars::Series.new("a", [1.0, 2.0, 3.0, 4.0, 6.0, 8.0])
s.rolling_quantile(0.33, window_size: 3)
# =>
# shape: (6,)
# Series: 'a' [f64]
# [
#         null
#         null
#         1.0
#         2.0
#         3.0
#         4.0
# ]

s.rolling_quantile(0.33, interpolation: "linear", window_size: 3)
# =>
# shape: (6,)
# Series: 'a' [f64]
# [
#         null
#         null
#         1.66
#         2.66
#         3.66
#         5.32
# ]

Parameters:

  • quantile (Float) —

    Quantile between 0.0 and 1.0.

  • interpolation ("nearest", "higher", "lower", "midpoint", "linear") (defaults to: "nearest") —

    Interpolation method.

  • window_size (Integer) (defaults to: 2) —

    The length of the window.

  • weights (Array) (defaults to: nil) —

    An optional slice with the same length as the window that will be multiplied elementwise with the values in the window.

  • min_periods (Integer) (defaults to: nil) —

    The number of values in the window that should be non-null before computing a result. If None, it will be set equal to window size.

  • center (Boolean) (defaults to: false) —

    Set the labels at the center of the window

Returns:



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# File 'lib/polars/series.rb', line 2872

def rolling_quantile(
  quantile,
  interpolation: "nearest",
  window_size: 2,
  weights: nil,
  min_periods: nil,
  center: false
)
  if min_periods.nil?
    min_periods = window_size
  end

  to_frame
    .select(
      Polars.col(name).rolling_quantile(
        quantile,
        interpolation: interpolation,
        window_size: window_size,
        weights: weights,
        min_periods: min_periods,
        center: center
      )
    )
    .to_series
end

#rolling_skew(window_size, bias: true) ⇒ Series

Compute a rolling skew.

Examples:

s = Polars::Series.new("a", [1.0, 2.0, 3.0, 4.0, 6.0, 8.0])
s.rolling_skew(3)
# =>
# shape: (6,)
# Series: 'a' [f64]
# [
#         null
#         null
#         0.0
#         0.0
#         0.381802
#         0.0
# ]

Parameters:

  • window_size (Integer) —

    Integer size of the rolling window.

  • bias (Boolean) (defaults to: true) —

    If false, the calculations are corrected for statistical bias.

Returns:



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# File 'lib/polars/series.rb', line 2921

def rolling_skew(window_size, bias: true)
  super
end

#rolling_std(window_size, weights: nil, min_periods: nil, center: false) ⇒ Series

Compute a rolling std dev.

A window of length window_size will traverse the array. The values that fill this window will (optionally) be multiplied with the weights given by the weight vector. The resulting values will be aggregated to their sum.

Examples:

s = Polars::Series.new("a", [1.0, 2.0, 3.0, 4.0, 6.0, 8.0])
s.rolling_std(3)
# =>
# shape: (6,)
# Series: 'a' [f64]
# [
#         null
#         null
#         1.0
#         1.0
#         1.527525
#         2.0
# ]

Parameters:

  • window_size (Integer) —

    The length of the window.

  • weights (Array) (defaults to: nil) —

    An optional slice with the same length as the window that will be multiplied elementwise with the values in the window.

  • min_periods (Integer) (defaults to: nil) —

    The number of values in the window that should be non-null before computing a result. If None, it will be set equal to window size.

  • center (Boolean) (defaults to: false) —

    Set the labels at the center of the window

Returns:



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# File 'lib/polars/series.rb', line 2702

def rolling_std(
  window_size,
  weights: nil,
  min_periods: nil,
  center: false
)
  to_frame
    .select(
      Polars.col(name).rolling_std(
        window_size,
        weights: weights,
        min_periods: min_periods,
        center: center
      )
    )
    .to_series
end

#rolling_sum(window_size, weights: nil, min_periods: nil, center: false) ⇒ Series

Apply a rolling sum (moving sum) over the values in this array.

A window of length window_size will traverse the array. The values that fill this window will (optionally) be multiplied with the weights given by the weight vector. The resulting values will be aggregated to their sum.

Examples:

s = Polars::Series.new("a", [1, 2, 3, 4, 5])
s.rolling_sum(2)
# =>
# shape: (5,)
# Series: 'a' [i64]
# [
#         null
#         3
#         5
#         7
#         9
# ]

Parameters:

  • window_size (Integer) —

    The length of the window.

  • weights (Array) (defaults to: nil) —

    An optional slice with the same length as the window that will be multiplied elementwise with the values in the window.

  • min_periods (Integer) (defaults to: nil) —

    The number of values in the window that should be non-null before computing a result. If None, it will be set equal to window size.

  • center (Boolean) (defaults to: false) —

    Set the labels at the center of the window

Returns:



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# File 'lib/polars/series.rb', line 2651

def rolling_sum(
  window_size,
  weights: nil,
  min_periods: nil,
  center: false
)
  to_frame
    .select(
      Polars.col(name).rolling_sum(
        window_size,
        weights: weights,
        min_periods: min_periods,
        center: center
      )
    )
    .to_series
end

#rolling_var(window_size, weights: nil, min_periods: nil, center: false) ⇒ Series

Compute a rolling variance.

A window of length window_size will traverse the array. The values that fill this window will (optionally) be multiplied with the weights given by the weight vector. The resulting values will be aggregated to their sum.

Examples:

s = Polars::Series.new("a", [1.0, 2.0, 3.0, 4.0, 6.0, 8.0])
s.rolling_var(3)
# =>
# shape: (6,)
# Series: 'a' [f64]
# [
#         null
#         null
#         1.0
#         1.0
#         2.333333
#         4.0
# ]

Parameters:

  • window_size (Integer) —

    The length of the window.

  • weights (Array) (defaults to: nil) —

    An optional slice with the same length as the window that will be multiplied elementwise with the values in the window.

  • min_periods (Integer) (defaults to: nil) —

    The number of values in the window that should be non-null before computing a result. If None, it will be set equal to window size.

  • center (Boolean) (defaults to: false) —

    Set the labels at the center of the window

Returns:



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# File 'lib/polars/series.rb', line 2753

def rolling_var(
  window_size,
  weights: nil,
  min_periods: nil,
  center: false
)
  to_frame
    .select(
      Polars.col(name).rolling_var(
        window_size,
        weights: weights,
        min_periods: min_periods,
        center: center
      )
    )
    .to_series
end

#round(decimals = 0) ⇒ Series

Round underlying floating point data by decimals digits.

Examples:

s = Polars::Series.new("a", [1.12345, 2.56789, 3.901234])
s.round(2)
# =>
# shape: (3,)
# Series: 'a' [f64]
# [
#         1.12
#         2.57
#         3.9
# ]

Parameters:

  • decimals (Integer) (defaults to: 0) —

    number of decimals to round by.

Returns:



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# File 'lib/polars/series.rb', line 2044

def round(decimals = 0)
  super
end

#sample(n: nil, frac: nil, with_replacement: false, shuffle: false, seed: nil) ⇒ Series

Sample from this Series.

Examples:

s = Polars::Series.new("a", [1, 2, 3, 4, 5])
s.sample(n: 2, seed: 0)
# =>
# shape: (2,)
# Series: 'a' [i64]
# [
#     1
#     5
# ]

Parameters:

  • n (Integer) (defaults to: nil) —

    Number of items to return. Cannot be used with frac. Defaults to 1 if frac is None.

  • frac (Float) (defaults to: nil) —

    Fraction of items to return. Cannot be used with n.

  • with_replacement (Boolean) (defaults to: false) —

    Allow values to be sampled more than once.

  • shuffle (Boolean) (defaults to: false) —

    Shuffle the order of sampled data points.

  • seed (Integer) (defaults to: nil) —

    Seed for the random number generator. If set to None (default), a random seed is used.

Returns:



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# File 'lib/polars/series.rb', line 2952

def sample(
  n: nil,
  frac: nil,
  with_replacement: false,
  shuffle: false,
  seed: nil
)
  if !n.nil? && !frac.nil?
    raise ArgumentError, "cannot specify both `n` and `frac`"
  end

  if n.nil? && !frac.nil?
    return Utils.wrap_s(_s.sample_frac(frac, with_replacement, shuffle, seed))
  end

  if n.nil?
    n = 1
  end
  Utils.wrap_s(_s.sample_n(n, with_replacement, shuffle, seed))
end

#search_sorted(element) ⇒ Integer

Find indices where elements should be inserted to maintain order.

Parameters:

  • element (Object) —

    Expression or scalar value.

Returns:

  • (Integer) 


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# File 'lib/polars/series.rb', line 1281

def search_sorted(element)
  Polars.select(Polars.lit(self).search_sorted(element))[0, 0]
end

#series_equal(other, null_equal: false, strict: false) ⇒ Boolean

Check if series is equal with another Series.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s2 = Polars::Series.new("b", [4, 5, 6])
s.series_equal(s)
# => true
s.series_equal(s2)
# => false

Parameters:

  • other (Series) —

    Series to compare with.

  • null_equal (Boolean) (defaults to: false) —

    Consider null values as equal.

  • strict (Boolean) (defaults to: false) —

    Don't allow different numerical dtypes, e.g. comparing :u32 with a :i64 will return false.

Returns:



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# File 'lib/polars/series.rb', line 1635

def series_equal(other, null_equal: false, strict: false)
  _s.series_equal(other._s, null_equal, strict)
end

#set(filter, value) ⇒ Series

Note:

Use of this function is frequently an anti-pattern, as it can block optimization (predicate pushdown, etc). Consider using Polars.when(predicate).then(value).otherwise(self) instead.

Set masked values.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.set(s == 2, 10)
# =>
# shape: (3,)
# Series: 'a' [i64]
# [
#         1
#         10
#         3
# ]

Parameters:

  • filter (Series) —

    Boolean mask.

  • value (Object) —

    Value with which to replace the masked values.

Returns:



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# File 'lib/polars/series.rb', line 1842

def set(filter, value)
  Utils.wrap_s(_s.send("set_with_mask_#{DTYPE_TO_FFINAME.fetch(dtype)}", filter._s, value))
end

#set_at_idx(idx, value) ⇒ Series

Set values at the index locations.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.set_at_idx(1, 10)
# =>
# shape: (3,)
# Series: 'a' [i64]
# [
#         1
#         10
#         3
# ]

Parameters:

  • idx (Object) —

    Integers representing the index locations.

  • value (Object) —

    Replacement values.

Returns:



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# File 'lib/polars/series.rb', line 1866

def set_at_idx(idx, value)
  if idx.is_a?(Integer)
    idx = [idx]
  end
  if idx.length == 0
    return self
  end

  idx = Series.new("", idx)
  if value.is_a?(Integer) || value.is_a?(Float) || Utils.bool?(value) || value.is_a?(String) || value.nil?
    value = Series.new("", [value])

    # if we need to set more than a single value, we extend it
    if idx.length > 0
      value = value.extend_constant(value[0], idx.length - 1)
    end
  elsif !value.is_a?(Series)
    value = Series.new("", value)
  end
  _s.set_at_idx(idx._s, value._s)
  self
end

#set_sorted(reverse: false) ⇒ Series

Note:

This can lead to incorrect results if this Series is not sorted!! Use with care!

Flags the Series as sorted.

Enables downstream code to user fast paths for sorted arrays.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.set_sorted.max
# => 3

Parameters:

  • reverse (Boolean) (defaults to: false) —

    If the Series order is reversed, e.g. descending.

Returns:



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# File 'lib/polars/series.rb', line 3450

def set_sorted(reverse: false)
  Utils.wrap_s(_s.set_sorted(reverse))
end

#shape ⇒ Array

Shape of this Series.

Returns:

  • (Array) 


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# File 'lib/polars/series.rb', line 116

def shape
  [_s.len]
end

#shift(periods = 1) ⇒ Series

Shift the values by a given period.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.shift(1)
# =>
# shape: (3,)
# Series: 'a' [i64]
# [
#         null
#         1
#         2
# ]

s.shift(-1)
# =>
# shape: (3,)
# Series: 'a' [i64]
# [
#         2
#         3
#         null
# ]

Parameters:

  • periods (Integer) (defaults to: 1) —

    Number of places to shift (may be negative).

Returns:



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# File 'lib/polars/series.rb', line 2409

def shift(periods = 1)
  super
end

#shift_and_fill(periods, fill_value) ⇒ Series

Shift the values by a given period and fill the resulting null values.

Parameters:

  • periods (Integer) —

    Number of places to shift (may be negative).

  • fill_value (Object) —

    Fill None values with the result of this expression.

Returns:



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# File 'lib/polars/series.rb', line 2421

def shift_and_fill(periods, fill_value)
  super
end

#shrink_dtype ⇒ Series

Shrink numeric columns to the minimal required datatype.

Shrink to the dtype needed to fit the extrema of this Series. This can be used to reduce memory pressure.

Returns:



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# File 'lib/polars/series.rb', line 3467

def shrink_dtype
  super
end

#shrink_to_fit(in_place: false) ⇒ Series

Shrink Series memory usage.

Shrinks the underlying array capacity to exactly fit the actual data. (Note that this function does not change the Series data type).

Returns:



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# File 'lib/polars/series.rb', line 3033

def shrink_to_fit(in_place: false)
  if in_place
    _s.shrink_to_fit
    self
  else
    series = clone
    series._s.shrink_to_fit
    series
  end
end

#shuffle(seed: nil) ⇒ Series

Shuffle the contents of this Series.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.shuffle(seed: 1)
# =>
# shape: (3,)
# Series: 'a' [i64]
# [
#         2
#         1
#         3
# ]

Parameters:

  • seed (Integer, nil) (defaults to: nil) —

    Seed for the random number generator.

Returns:



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# File 'lib/polars/series.rb', line 3358

def shuffle(seed: nil)
  super
end

#sign ⇒ Series

Compute the element-wise indication of the sign.

Examples:

s = Polars::Series.new("a", [-9.0, -0.0, 0.0, 4.0, nil])
s.sign
# =>
# shape: (5,)
# Series: 'a' [i64]
# [
#         -1
#         0
#         0
#         1
#         null
# ]

Returns:



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# File 'lib/polars/series.rb', line 2107

def sign
  super
end

#sin ⇒ Series

Compute the element-wise value for the sine.

Examples:

s = Polars::Series.new("a", [0.0, Math::PI / 2.0, Math::PI])
s.sin
# =>
# shape: (3,)
# Series: 'a' [f64]
# [
#         0.0
#         1.0
#         1.2246e-16
# ]

Returns:



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# File 'lib/polars/series.rb', line 2126

def sin
  super
end

#sinh ⇒ Series

Compute the element-wise value for the hyperbolic sine.

Examples:

s = Polars::Series.new("a", [1.0, 0.0, -1.0])
s.sinh
# =>
# shape: (3,)
# Series: 'a' [f64]
# [
#         1.175201
#         0.0
#         -1.175201
# ]

Returns:



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# File 'lib/polars/series.rb', line 2302

def sinh
  super
end

#skew(bias: true) ⇒ Float?

Compute the sample skewness of a data set.

For normally distributed data, the skewness should be about zero. For unimodal continuous distributions, a skewness value greater than zero means that there is more weight in the right tail of the distribution. The function skewtest can be used to determine if the skewness value is close enough to zero, statistically speaking.

Parameters:

  • bias (Boolean) (defaults to: true) —

    If false, the calculations are corrected for statistical bias.

Returns:

  • (Float, nil) 


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# File 'lib/polars/series.rb', line 3246

def skew(bias: true)
  _s.skew(bias)
end

#slice(offset, length = nil) ⇒ Series

Get a slice of this Series.

Examples:

s = Polars::Series.new("a", [1, 2, 3, 4])
s.slice(1, 2)
# =>
# shape: (2,)
# Series: 'a' [i64]
# [
#         2
#         3
# ]

Parameters:

  • offset (Integer) —

    Start index. Negative indexing is supported.

  • length (Integer, nil) (defaults to: nil) —

    Length of the slice. If set to nil, all rows starting at the offset will be selected.

Returns:



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# File 'lib/polars/series.rb', line 987

def slice(offset, length = nil)
  super
end

#sort(reverse: false, in_place: false) ⇒ Series

Sort this Series.

Examples:

s = Polars::Series.new("a", [1, 3, 4, 2])
s.sort
# =>
# shape: (4,)
# Series: 'a' [i64]
# [
#         1
#         2
#         3
#         4
# ]
s.sort(reverse: true)
# =>
# shape: (4,)
# Series: 'a' [i64]
# [
#         4
#         3
#         2
#         1
# ]

Parameters:

  • reverse (Boolean) (defaults to: false) —

    Reverse sort.

  • in_place (Boolean) (defaults to: false) —

    Sort in place.

Returns:



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# File 'lib/polars/series.rb', line 1169

def sort(reverse: false, in_place: false)
  if in_place
    self._s = _s.sort(reverse)
    self
  else
    Utils.wrap_s(_s.sort(reverse))
  end
end

#sqrt ⇒ Series

Compute the square root of the elements.

Returns:



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# File 'lib/polars/series.rb', line 347

def sqrt
  self**0.5
end

#std(ddof: 1) ⇒ Float?

Get the standard deviation of this Series.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.std
# => 1.0

Parameters:

  • ddof (Integer) (defaults to: 1) —

    “Delta Degrees of Freedom”: the divisor used in the calculation is N - ddof, where N represents the number of elements.

Returns:

  • (Float, nil) 


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# File 'lib/polars/series.rb', line 584

def std(ddof: 1)
  if !is_numeric
    nil
  else
    to_frame.select(Polars.col(name).std(ddof: ddof)).to_series[0]
  end
end

#str ⇒ StringNameSpace

Create an object namespace of all string related methods.

Returns:



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# File 'lib/polars/series.rb', line 3495

def str
  StringNameSpace.new(self)
end

#struct ⇒ StructNameSpace

Create an object namespace of all struct related methods.

Returns:



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# File 'lib/polars/series.rb', line 3502

def struct
  StructNameSpace.new(self)
end

#sum ⇒ Numeric

Note:

Dtypes :i8, :u8, :i16, and :u16 are cast to :i64 before summing to prevent overflow issues.

Reduce this Series to the sum value.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.sum
# => 6

Returns:

  • (Numeric) 


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# File 'lib/polars/series.rb', line 511

def sum
  _s.sum
end

#tail(n = 10) ⇒ Series

Get the last n rows.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.tail(2)
# =>
# shape: (2,)
# Series: 'a' [i64]
# [
#         2
#         3
# ]

Parameters:

  • n (Integer) (defaults to: 10) —

    Number of rows to return.

Returns:



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# File 'lib/polars/series.rb', line 1116

def tail(n = 10)
  to_frame.select(Utils.col(name).tail(n)).to_series
end

#take(indices) ⇒ Series

Take values by index.

Examples:

s = Polars::Series.new("a", [1, 2, 3, 4])
s.take([1, 3])
# =>
# shape: (2,)
# Series: 'a' [i64]
# [
#         2
#         4
# ]

Parameters:

  • indices (Array) —

    Index location used for selection.

Returns:



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# File 'lib/polars/series.rb', line 1324

def take(indices)
  to_frame.select(Polars.col(name).take(indices)).to_series
end

#take_every(n) ⇒ Series

Take every nth value in the Series and return as new Series.

Examples:

s = Polars::Series.new("a", [1, 2, 3, 4])
s.take_every(2)
# =>
# shape: (2,)
# Series: 'a' [i64]
# [
#         1
#         3
# ]

Returns:



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# File 'lib/polars/series.rb', line 1134

def take_every(n)
  super
end

#tan ⇒ Series

Compute the element-wise value for the tangent.

Examples:

s = Polars::Series.new("a", [0.0, Math::PI / 2.0, Math::PI])
s.tan
# =>
# shape: (3,)
# Series: 'a' [f64]
# [
#         0.0
#         1.6331e16
#         -1.2246e-16
# ]

Returns:



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# File 'lib/polars/series.rb', line 2164

def tan
  super
end

#tanh ⇒ Series

Compute the element-wise value for the hyperbolic tangent.

Examples:

s = Polars::Series.new("a", [1.0, 0.0, -1.0])
s.tanh
# =>
# shape: (3,)
# Series: 'a' [f64]
# [
#         0.761594
#         0.0
#         -0.761594
# ]

Returns:



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# File 'lib/polars/series.rb', line 2340

def tanh
  super
end

#time_unit ⇒ String

Get the time unit of underlying Datetime Series as "ns", "us", or "ms".

Returns:

  • (String) 


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# File 'lib/polars/series.rb', line 123

def time_unit
  _s.time_unit
end

#to_a ⇒ Array

Convert this Series to a Ruby Array. This operation clones data.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.to_a
# => [1, 2, 3]

Returns:

  • (Array) 


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# File 'lib/polars/series.rb', line 1711

def to_a
  _s.to_a
end

#to_dummies ⇒ DataFrame

Get dummy variables.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.to_dummies
# =>
# shape: (3, 3)
# ┌─────┬─────┬─────┐
# │ a_1 ┆ a_2 ┆ a_3 │
# │ --- ┆ --- ┆ --- │
# │ u8  ┆ u8  ┆ u8  │
# ╞═════╪═════╪═════╡
# │ 1   ┆ 0   ┆ 0   │
# ├╌╌╌╌╌┼╌╌╌╌╌┼╌╌╌╌╌┤
# │ 0   ┆ 1   ┆ 0   │
# ├╌╌╌╌╌┼╌╌╌╌╌┼╌╌╌╌╌┤
# │ 0   ┆ 0   ┆ 1   │
# └─────┴─────┴─────┘

Returns:



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# File 'lib/polars/series.rb', line 661

def to_dummies
  Utils.wrap_df(_s.to_dummies)
end

#to_frame ⇒ DataFrame

Cast this Series to a DataFrame.

Returns:



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# File 'lib/polars/series.rb', line 406

def to_frame
  Utils.wrap_df(RbDataFrame.new([_s]))
end

#to_physical ⇒ Series

Cast to physical representation of the logical dtype.

  • :date -> :i32
  • :datetime -> :i64
  • :time -> :i64
  • :duration -> :i64
  • :cat -> :u32
  • other data types will be left unchanged.

Examples:

s = Polars::Series.new("values", ["a", nil, "x", "a"])
s.cast(:cat).to_physical
# =>
# shape: (4,)
# Series: 'values' [u32]
# [
#         0
#         null
#         1
#         0
# ]

Returns:



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# File 'lib/polars/series.rb', line 1699

def to_physical
  super
end

#to_s ⇒ String Also known as: inspect

Returns a string representing the Series.

Returns:

  • (String) 


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# File 'lib/polars/series.rb', line 130

def to_s
  _s.to_s
end

#top_k(k: 5, reverse: false) ⇒ Boolean

Return the k largest elements.

If reverse: true, the smallest elements will be given.

Parameters:

  • k (Integer) (defaults to: 5) —

    Number of elements to return.

  • reverse (Boolean) (defaults to: false) —

    Return the smallest elements.

Returns:



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# File 'lib/polars/series.rb', line 1188

def top_k(k: 5, reverse: false)
  super
end

#unique(maintain_order: false) ⇒ Series

Get unique elements in series.

Examples:

s = Polars::Series.new("a", [1, 2, 2, 3])
s.unique.sort
# =>
# shape: (3,)
# Series: 'a' [i64]
# [
#         1
#         2
#         3
# ]

Parameters:

  • maintain_order (Boolean) (defaults to: false) —

    Maintain order of data. This requires more work.

Returns:



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# File 'lib/polars/series.rb', line 1303

def unique(maintain_order: false)
  super
end

#unique_counts ⇒ Series

Return a count of the unique values in the order of appearance.

Examples:

s = Polars::Series.new("id", ["a", "b", "b", "c", "c", "c"])
s.unique_counts
# =>
# shape: (3,)
# Series: 'id' [u32]
# [
#         1
#         2
#         3
# ]

Returns:



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# File 'lib/polars/series.rb', line 707

def unique_counts
  super
end

#value_counts(sort: false) ⇒ DataFrame

Count the unique values in a Series.

Examples:

s = Polars::Series.new("a", [1, 2, 2, 3])
s.value_counts.sort("a")
# =>
# shape: (3, 2)
# ┌─────┬────────┐
# │ a   ┆ counts │
# │ --- ┆ ---    │
# │ i64 ┆ u32    │
# ╞═════╪════════╡
# │ 1   ┆ 1      │
# ├╌╌╌╌╌┼╌╌╌╌╌╌╌╌┤
# │ 2   ┆ 2      │
# ├╌╌╌╌╌┼╌╌╌╌╌╌╌╌┤
# │ 3   ┆ 1      │
# └─────┴────────┘

Parameters:

  • sort (Boolean) (defaults to: false) —

    Ensure the output is sorted from most values to least.

Returns:



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# File 'lib/polars/series.rb', line 688

def value_counts(sort: false)
  Utils.wrap_df(_s.value_counts(sort))
end

#var(ddof: 1) ⇒ Float?

Get variance of this Series.

Examples:

s = Polars::Series.new("a", [1, 2, 3])
s.var
# => 1.0

Parameters:

  • ddof (Integer) (defaults to: 1) —

    “Delta Degrees of Freedom”: the divisor used in the calculation is N - ddof, where N represents the number of elements.

Returns:

  • (Float, nil) 


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# File 'lib/polars/series.rb', line 604

def var(ddof: 1)
  if !is_numeric
    nil
  else
    to_frame.select(Polars.col(name).var(ddof: ddof)).to_series[0]
  end
end

#zip_with(mask, other) ⇒ Series

Take values from self or other based on the given mask.

Where mask evaluates true, take values from self. Where mask evaluates false, take values from other.

Examples:

s1 = Polars::Series.new([1, 2, 3, 4, 5])
s2 = Polars::Series.new([5, 4, 3, 2, 1])
s1.zip_with(s1 < s2, s2)
# =>
# shape: (5,)
# Series: '' [i64]
# [
#         1
#         2
#         3
#         2
#         1
# ]

mask = Polars::Series.new([true, false, true, false, true])
s1.zip_with(mask, s2)
# =>
# shape: (5,)
# Series: '' [i64]
# [
#         1
#         4
#         3
#         2
#         5
# ]

Parameters:

  • mask (Series) —

    Boolean Series.

  • other (Series) —

    Series of same type.

Returns:



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# File 'lib/polars/series.rb', line 2465

def zip_with(mask, other)
  Utils.wrap_s(_s.zip_with(mask._s, other._s))
end

#|(other) ⇒ Series

Bitwise OR.

Returns:



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# File 'lib/polars/series.rb', line 148

def |(other)
  if !other.is_a?(Series)
    other = Series.new([other])
  end
  Utils.wrap_s(_s.bitor(other._s))
end