シグモイド関数をグラフ表示

Ubuntu 16.04 で試した

 % sudo apt-get install gnuplot
 % gem install gnuplot

require 'gnuplot'

def sigmod( x ) 
  1.0 / (1.0 + Math.exp( -x ) ) 
end

Gnuplot.open do |gp|
    Gnuplot::Plot.new(gp) do |plot|
      plot.title 'sample'
      plot.ylabel 'ylabel'
      plot.xlabel 'xlabel'

      x = (-100..100).collect{|v| v.to_f*0.1 }
      y = x.map {|f| sigmod(f) }

      plot.data << Gnuplot::DataSet.new( [x,y] ) do |ds|
        ds.with = "lines"
        ds.notitle
      end
    end 
end