Class: Daru::DataFrame

Inherits:
Object
  • Object
show all
Defined in:
lib/daru/dataframe.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(source, fields = [], name = SecureRandom.uuid) ⇒ DataFrame

Returns a new instance of DataFrame.



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# File 'lib/daru/dataframe.rb', line 12

def initialize source, fields=[], name=SecureRandom.uuid
  if source.empty?
    @vectors = fields.inject({}){ |a,x| a[x]=Daru::Vector.new; a}
  else
    @vectors = source
  end

  @fields = fields.empty? ? source.keys.sort : fields
  @name   = name
 
  check_length
  set_fields_order if @vectors.keys.sort != @fields.sort
  set_vector_names
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *args) ⇒ Object 



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# File 'lib/daru/dataframe.rb', line 141

def method_missing(name, *args)
  if md = name.match(/(.+)\=/)
    insert_vector name[/(.+)\=/].delete("="), args[0]
  elsif self.has_vector? name
    column name
  else
    super(name, *args)
  end
end

Instance Attribute Details

#fields ⇒ Object (readonly)

Returns the value of attribute fields.



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# File 'lib/daru/dataframe.rb', line 6

def fields
  @fields
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/daru/dataframe.rb', line 10

def name
  @name
end

#size ⇒ Object (readonly)

Returns the value of attribute size.



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# File 'lib/daru/dataframe.rb', line 8

def size
  @size
end

#vectors ⇒ Object (readonly)

Returns the value of attribute vectors.



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# File 'lib/daru/dataframe.rb', line 4

def vectors
  @vectors
end

Class Method Details

.from_csv(file, opts = {}) {|csv| ... } ⇒ Object

Yields:

  • (csv) 


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# File 'lib/daru/dataframe.rb', line 27

def self.from_csv file, opts={}
  opts[:col_sep]           ||= ','
  opts[:headers]           ||= true
  opts[:converters]        ||= :numeric
  opts[:header_converters] ||= :symbol

  csv = CSV.open file, 'r', opts

  yield csv if block_given?

  first = true
  df    = nil

  csv.each do |row|
    if first
      df = Daru::DataFrame.new({}, csv.headers)
      first = false
    end

    df.insert_row row
  end

  df
end

Instance Method Details

#[](name) ⇒ Object 



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# File 'lib/daru/dataframe.rb', line 61

def [](name)
  column name
end

#[]=(name, vector) ⇒ Object 



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# File 'lib/daru/dataframe.rb', line 65

def []=(name, vector)
  insert_vector name, vector
end

#column(name) ⇒ Object 



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# File 'lib/daru/dataframe.rb', line 52

def column name
  @vectors[name]
end

#delete(name) ⇒ Object 



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# File 'lib/daru/dataframe.rb', line 56

def delete name
  @vectors.delete name
  @fields.delete name
end

#each_column ⇒ Object 



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# File 'lib/daru/dataframe.rb', line 96

def each_column
  @vectors.values.each do |column|
    yield column
  end
end

#each_row ⇒ Object 



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# File 'lib/daru/dataframe.rb', line 84

def each_row
  0.upto(@size) do |index|
    yield row(index)
  end
end

#each_row_with_index ⇒ Object 



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# File 'lib/daru/dataframe.rb', line 90

def each_row_with_index
  0.upto(@size) do |index|
    yield row(index), index
  end
end

#has_vector?(vector) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/daru/dataframe.rb', line 80

def has_vector? vector
  !!@vectors[vector]
end

#insert_row(row) ⇒ Object

Raises:

  • (Exception) 


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# File 'lib/daru/dataframe.rb', line 110

def insert_row row
  raise Exception, "Expected new row to same as the number of rows \ 
    in the DataFrame" if row.size != @fields.size

  @fields.each_with_index do |field, index|
    @vectors[field] << row[index]
  end
end

#insert_vector(name, vector) ⇒ Object

Raises:

  • (Exeception) 


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# File 'lib/daru/dataframe.rb', line 102

def insert_vector name, vector
  raise Exeception, "Expected vector size to be same as DataFrame\ 
    size." if vector.size != self.size

  @vectors.merge({name => vector})
  @fields << name
end

#row(index) ⇒ Object

Raises:

  • (Exception) 


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# File 'lib/daru/dataframe.rb', line 69

def row index
  raise Exception, "Expected index to be within bounds" if index > @size

  row = []
  self.each_column do |column|
    row << column[index]
  end

  row
end

#to_html(threshold = 15) ⇒ Object 



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# File 'lib/daru/dataframe.rb', line 119

def to_html(threshold=15)
  html = '<table>'

  self.each_row_with_index do |row, index|
    break if index > threshold and index <= @size
    html += '<tr>'
    row.each{ |val| html.concat('<td>' + val.to_s + '</td>') }
    html += '</tr>'
    if i == threshold
      html += '<tr>'
      row.size.times { html.concat('<td>...</td>') }
      html += '</tr>'
    end
  end

  html += '</table>'
end

#to_s ⇒ Object 



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# File 'lib/daru/dataframe.rb', line 137

def to_s
  to_html
end