Method: Enumerable#ewise

Defined in:
lib/core/facets/enumerable/ewise.rb

#ewise(count = 1) ⇒ Object Also known as: elementwise

Returns an elementwise Functor designed to make R-like elementwise operations possible. This is very much like the #every method, but it treats array argument specially.

([1,2].ewise + 3)          #=> [4,5]

Vector to vector

([1,2].ewise + [4,5])      #=> [5,7]

Special thanks to Martin DeMello for helping to develop this.



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# File 'lib/core/facets/enumerable/ewise.rb', line 19

def ewise(count=1)
  Functor.new do |op,*args|
    if args.empty?
      r = self
      count.times do
        r = r.collect{ |a| a.send(op) }
      end
      r
    else
      r = args.collect do |arg|
        if Array === arg #arg.kind_of?(Enumerable)
          x = self
          count.times do
            ln = (arg.length > length ? length : arg.length )
            x = x.slice(0...ln)
            x = x.zip(arg[0...ln])
            x = x.collect{ |a,b| a.send(op,b) }  #x = x.collect{ |a,b| b ? a.send(op,b) : nil }
          end
          x
        else
          x = self
          count.times do
            x = x.collect{ |a| a.send(op,arg) }
          end
          x
        end
      end
      r.flatten! if args.length == 1
      r
    end
  end
end