Awesome

Numo::Gnuplot : Gnuplot interface for Ruby

Alpha version under development.

GitHub site
RubyGems site
Demo repository contains > 500 plots!
API doc
Introduction.ja (in Japanese)

Although there are many other Gnuplot interface libraries for Ruby, none of them have so simple interface as to show an XY data plot by just typing:

plot x,y

Numo::Gnuplot achieves this by providing only one class which has the same inteface as Gnuplot command line, and no other class which causes extra learning costs.

Installation

Add this line to your application's Gemfile:

gem 'numo-gnuplot'

And then execute:

$ bundle

Or install it yourself as:

$ gem install numo-gnuplot

Demo

Ruby/Numo::Gnuplot Demo

Usage

All examples require to load Numo::Gnuplot class:

require "numo/gnuplot"

The first example showing how it works.

gp = Numo::Gnuplot.new
gp.set title:"Example Plot"
gp.plot "sin(x)",w:"lines"

You can omit receiver.

Numo::Gnuplot.new.instance_eval do
  set title:"Example Plot"
  plot "sin(x)",w:"lines"
end

The same thing in short.

Numo.gnuplot do
  set title:"Example Plot"
  plot "sin(x)",w:"lines"
end

In these examples, the following command lines are send to Gnuplot.

set title "Example Plot"
plot sin(x) w lines

Interactive plotting with IRB:

$ irb -r numo/gnuplot
irb(main):001:0> pushb Numo.gnuplot
irb(gnuplot):002:0> set t:"Example Plot"
irb(gnuplot):003:0> plot "sin(x)",w:"lines"

Plotting X-Y data stored in arrays.

require "numo/gnuplot"

x = (0..100).map{|i| i*0.1}
y = x.map{|i| Math.sin(i)}

Numo.gnuplot do
  set title:"X-Y data plot"
  plot x,y, w:'lines', t:'sin(x)'
end

Plotting X-Y data stored in NArrays.

require "numo/gnuplot"
require "numo/narray"

x = Numo::DFloat[0..100]/10
y = Numo::NMath.sin(x)

Numo.gnuplot do
  set title:"X-Y data plot in Numo::NArray"
  plot x,y, w:'lines', t:'sin(x)'
end

Multiple data are separated by Hash or put into Array.

require 'numo/gnuplot'
require 'numo/narray'
NM = Numo::NMath

n = 60
x = Numo::DFloat[-n..n]/n*10

Numo.gnuplot do
  set title:"multiple data series"

  # Hash-separated form
  plot x,NM.sin(x), {w:'points',t:'sin(x)'}, x,x*NM.sin(x),{w:"lines",t:'x*sin(x)'}

  # or Array-separated form
  plot [x,NM.sin(x), w:'points',t:'sin(x)'], [x,x*NM.sin(x),w:"lines",t:'x*sin(x)']
  # (here last item in each Array should be Hash, to distinguish from data array)

end

Plotting 2D arrays in 3D.

require 'numo/gnuplot'
require 'numo/narray'

n = 60
x = (Numo::DFloat.new(1,n).seq/n-0.5)*30
y = (Numo::DFloat.new(n,1).seq/n-0.5)*30
r = Numo::NMath.sqrt(x**2+y**2) + 1e-10
z = Numo::NMath.sin(r)/r

Numo.gnuplot do
  set title:'2D data plot'
  set dgrid3d:[60,60]
  splot z, w:'pm3d', t:'sin(r)/r'
end

IRuby

Numo::Gnuplot is compatible with IRuby.

Embedding a plot into iRuby Notebook.

Numo::Gnuplot::NotePlot.new do
  plot "sin(x)"
end

The same thing in short.

Numo.noteplot do
  plot "sin(x)"
end

Gnuplot methods

Numo::Gnuplot class methods succeeded from Gnuplot commands:

clear
exit
fit(*args)
help(topic)
load(filename)
pause(*args)
plot(*args)
quit
reflesh
replot
reset(option)
set(*options)
show(option)
splot(*args)
unset(*options)
update(*files)

Numo::Gnuplot class methods renamed from Gnuplot commands:

raise_plot(plot_window) -- 'raise' command
lower_plot(plot_window) -- 'lower' command

Numo::Gnuplot-specific methods:

debug_off -- turn off debug print.
debug_on -- turn on debug print.
run(command_line) -- send command-line string to Gnuplot directly.
output(filename,[term,*opts]) -- output current plot to file. If term is omitted, an extension in filename is regarded as a term name. This invokes the next commands;

set terminal:[term,*opts]
set output:filename; refresh

var(name) -- returns variable content in the Gnuplot context.

See API doc for more.

Related Work

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/ruby-numo/numo-gnuplot.