Module: DF::Filter

Included in:
DataFrame
Defined in:
lib/data_frame/core/filter.rb

Overview

:nodoc:

Instance Method Summary collapse

Instance Method Details

#filter(as = Array, &block) ⇒ Object 



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# File 'lib/data_frame/core/filter.rb', line 18

def filter(as=Array, &block)
  new_data_frame = self.clone
  new_data_frame.filter!(as, &block)
end

#filter!(as = Array, &block) ⇒ Object

Takes a block to evaluate on each row. The row can be converted into an OpenStruct or a Hash for easier filter methods. Note, don’t try this with a hash or open struct unless you have facets available.



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# File 'lib/data_frame/core/filter.rb', line 7

def filter!(as=Array, &block)
  as = infer_class(as)
  items = []
  self.items.each do |row|
    value = block.call(cast_row(row, as))
    items << row if value
  end
  @items = items.dup
  self
end

#filter_by_category(hash) ⇒ Object 



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# File 'lib/data_frame/core/filter.rb', line 23

def filter_by_category(hash)
  new_data_frame = self.dup
  hash.each do |key, value|
    key = key.to_underscore_sym
    next unless self.labels.include?(key)
    value = [value] unless value.is_a?(Array) or value.is_a?(Range)
    new_data_frame.filter!(:hash) {|row| value.include?(row[key])}
  end
  new_data_frame
end

#filter_by_category!(hash) ⇒ Object 



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# File 'lib/data_frame/core/filter.rb', line 34

def filter_by_category!(hash)
  hash.each do |key, value|
    key = key.to_underscore_sym
    next unless self.labels.include?(key)
    value = [value] unless value.is_a?(Array) or value.is_a?(Range)
    self.filter!(:hash) {|row| value.include?(row[key])}
  end
end