gsl-rb wraps the GNU Scientific Library using FFI. See also Ruby/GSL for a c-based wrapper. GSL-rb uses FFI so it may be used from JRuby or any Ruby with FFI support.
- Author
-
Patrick Mahoney ([email protected])
- Copyright
-
Copyright © 2010 Patrick Mahoney
- License
-
MIT
Objects such as vectors and matricies are fixed size objects; they do not automatically grow as new members are added.
The main numeric objects are GSL::Vector and GSL::Matrix. These classes have subclasses of several data typse such as GSL::Vector::Int. The default GSL::Vector.new simply calls GSL::Vector::Double.new, similar for the matrix classes.
At the moment, only type double should be expected to work.
A Vector is a one-dimensional array of numbers. The default Vector class uses machine ‘double’ values. Other types include Vector::Int and others that use machine ‘int’ values. Note these types refer to the underlying C-types and not to Ruby classes.
A Matrix is a two-dimensional matrix. When indexing a matrix, [row, col] is the convention used.
require 'gsl' v = GSL::Vector.new([1,2,3,4]) v[0] => 1 v[1] => 2 m = GSL::Matrix.new([[1,2,3], [4,5,6], [7,8,9]]) m[0,0] => 1 m[0,1] => 2 m[0,2] => 3 m[2,2] => 9 m = GSL::Matrix.new(3, 3, [1,2,3,4,5,6,7,8,9]) m.to_ary_rows => [[1,2,3], [4,5,6], [7,8,9]]
require 'gsl'
require 'gsl/blas'
a = GSL::Vector.new([1,2,3])
b = GSL::Vector.new([2,2,2])
a.dot(b) => 12
b.magnitude => 3.46...
m1 = GSL::Matrix.new([[ 1, 2, 3],
[ 4, 5, 6],
[ 7, 8, 9],
[10,11,12]])
m2 = GSL::Matrix.new([[-2],
[ 1],
[ 0]])
m1.mul(m2).to_ary_rows => [[ 0]
[-3],
[-6],
[-9]]
require 'gsl' require 'gsl/linalg' m = GSL::Matrix.new([[0.18, 0.60, 0.57, 0.96], [0.41, 0.24, 0.99, 0.58], [0.14, 0.30, 0.97, 0.66], [0.51, 0.13, 0.19, 0.85]]) # Can also get the inverse after LU_decomp! But as GSL docs state: # "It is preferable to avoid direct use of the inverse whenever # possible, as the linear solver functions can obtain the same result # more efficiently and reliably" m.inv