Ruby: building a plot of function

Question

What's the easiest way to build a plot of a function under Ruby? Any suggestions as to the special graphical library?

update: under windows only :-(

update 2: found the following gem as a best solution so far https://github.com/clbustos/rubyvis

Answer 1

Is gnuplot a possible option?:

require 'gnuplot.rb'
Gnuplot.open { |gp|
    Gnuplot::Plot.new( gp ) { |plot|
        plot.output "testgnu.pdf"
        plot.terminal "pdf colour size 27cm,19cm"

        plot.xrange "[-10:10]"
        plot.title  "Sin Wave Example"
        plot.ylabel "x"
        plot.xlabel "sin(x)"

        plot.data << Gnuplot::DataSet.new( "sin(x)" ) { |ds|
            ds.with = "lines"
            ds.linewidth = 4
        }
        plot.data << Gnuplot::DataSet.new( "cos(x)" ) { |ds|
            ds.with = "impulses"
            ds.linewidth = 4
        }
    }
}

Answer 2

In case anyone else stumbles over this, I was able to use gnuplot using the following code:

require 'rubygems'
require 'gnuplot' 

Gnuplot.open do |gp|
  Gnuplot::Plot.new( gp ) do |plot|

    plot.xrange "[-10:10]"
    plot.title  "Sin Wave Example"
    plot.ylabel "x"
    plot.xlabel "sin(x)"

    plot.data << Gnuplot::DataSet.new( "sin(x)" ) do |ds|
      ds.with = "lines"
      ds.linewidth = 4
    end
  end
end

Requiring rubygems and using the correct gem name for gnuplot was the key for me.

Answer 3

This is my go-to graphing library: SVG::Graph

Answer 4

I really like tioga. It can produce incredibly high quality, publication-ready graphs in latex.

Answer 5

use SVG::Graph::Line like this:

require 'SVG/Graph/Line'

  fields = %w(Jan Feb Mar);
  data_sales_02 = [12, 45, 21]
  data_sales_03 = [15, 30, 40]

  graph = SVG::Graph::Line.new({
          :height => 500,
          :width => 300,
    :fields => fields,
  })

  graph.add_data({
          :data => data_sales_02,
    :title => 'Sales 2002',
  })

  graph.add_data({
          :data => data_sales_03,
    :title => 'Sales 2003',
  })

  print "Content-type: image/svg+xml\r\n\r\n";
  print graph.burn();

Answer 6

There's Microsoft Excel.

If so, the Ruby on Windows blog may be useful, as are questions tagged win32ole and ruby.