Ruby/GSL, a Ruby interface to GSL (GNU Scientific library)

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License.


Ruby/GSL is a Ruby interface to the GNU Scientific Library (GSL), for numerical computing with Ruby.

Ruby/GSL is compatible with GSL versions upto 2.1.

Usage with GSL 2.1

As of this release, GSL 2.1 has not made it's way into the Debian stable repositories. Hence, after compiling GSL 2.1 from source, you will need to set the installation location in your LD_LIBRARY_PATH variable. After following standard GSL 2.1 installation procedures, you should do: export LD_LIBRARY_PATH=/usr/local/lib

The need to do this should not arise if GSL has been installed from apt-get.


Ruby/GSL may be installed as a Ruby Gem by simply running

gem install gsl

Note that the GSL libraries must already be installed before Ruby/GSL can be installed:

Debian/Ubuntu: +libgsl0-dev+ Fedora/SuSE: +gsl-devel+ Gentoo: +sci-libs/gsl+ OS X: brew install gsl

It is recommended to install the GNU plotutils package. Some of the example scripts in the +examples/+ directory use the +graph+ utility included in the package to plot the results. Windows cygwin binaries of GNU plotutils and related packages are available here.

NMatrix and NArray usage

Ruby/GSL works with NMatrix and NArray for a variety of methods. See the docs for a detailed list.

Basic Installation

In order to use rb-gsl with NMatrix you must first set the NMATRIX environment variable and then install rb-gsl: gem install nmatrix export NMATRIX=1 gem install rb-gsl

This will compile rb-gsl with NMatrix specific functions.

For using rb-gsl with NArray: gem install narray export NARRAY=1 gem install rb-gsl

Note that setting both NMATRIX and NARRAY variables will lead to undefined behaviour. Only one can be used at a time.

NMatrix basic usage

Convert an NMatrix 1D vector to GSL::Vector:

require 'gsl'

nm =[5], [1,2,3,4,5], dtype: :float64)
#=> [1.0, 2.0, 3.0, 4.0, 5.0]
# => GSL::Vector
# [ 1.000e+00 2.000e+00 3.000e+00 4.000e+00 5.000e+00 ]

Convert an integer 2D NMatrix to GSL::Matrix::Int:

require 'gsl'
nm =[3,3], [2]*9, dtype: :int32)
#  [2, 2, 2]   [2, 2, 2]   [2, 2, 2] ]
#=> GSL::Matrix::Int
#[ 2 2 2 
#  2 2 2 
#  2 2 2 ]

Convert GSL::Vector to 1D NMatrix:

g = GSL::Vector.alloc(1,2,3,4)
# => GSL::Vector
# [ 1.000e+00 2.000e+00 3.000e+00 4.000e+00 ]
# => [1.0, 2.0, 3.0, 4.0]

to_nm can be used on all sorts of GSL::Vector and GSL::Matrix objects to convert them to NMatrix.

For a detailed list of methods that are compatible with NMatrix, see 'nmatrix' in the docs.


The Ruby/GSL reference manual follows and borrows large parts of the GSL reference manual.


See scripts in +examples/+ and +test/+ directories.

  • ruby-gsl: Another Ruby binding, developed by Arno Erpenbeck.


Ruby/GSL is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY.

Bug Reports

Any bug reports are welcome. If you encounter bugs in Ruby/GSL, please report them on GitHub(

Testing and Contributing

If you wish to make contributions, run the following commands to clone and test the gem on your local machine: git clone cd rb-gsl bash

This will run tests with and without NMatrix/NArray.

Documentation: Source code: RubyGem: Bug tracker: Travis CI: