NAME
Math::Libgsl::Permutation - An interface to libgsl, the Gnu Scientific Library - Permutations.
SYNOPSIS
use Math::Libgsl::Raw::Permutation :ALL;
use Math::Libgsl::Permutation;
DESCRIPTION
Math::Libgsl::Permutation provides an interface to the permutation functions of libgsl, the GNU Scientific Library.
This package provides both the low-level interface to the C library (Raw) and a more comfortable interface layer for the Raku programmer.
new(:$elems!)
new($elems!)
The constructor accepts one parameter: the number of elements in the permutation; it can be passed as a Pair or as a single value. The permutation object is already initialized to the identity (0, 1, 2 … $elems - 1).
All the following methods throw on error if they return self, otherwise they fail on error.
init()
This method initialize the permutation object to the identity and returns self.
copy($src! where * ~~ Math::Libgsl::Permutation)
This method copies the permutation $src into the current permutation object and returns self.
get(Int $elem! --> Int)
This method returns the permutation value at position $elem.
all(--> Seq)
This method returns a Seq of all the elements of the current permutation.
swap(Int $elem1!, Int $elem2!)
This method swamps two elements of the current permutation object and returns self.
size(--> Int)
This method returns the size of the current permutation object.
is-valid(--> Bool)
This method checks whether the current permutation is valid: the n elements should contain each of the numbers 0 to n - 1 once and only once.
reverse()
This method reverses the order of the elements of the current permutation object.
inverse($dst! where * ~~ Math::Libgsl::Permutation)
This method computes the inverse of the current permutation and stores the result into $dst.
next()
prev()
These functions advance or step backwards the permutation and return self, useful for method chaining.
bnext(--> Bool)
bprev(--> Bool)
These functions advance or step backwards the permutation and return a Bool: True if successful or False if there's no more permutation to produce.
permute(@data!, Int $stride! --> List)
This method applies the current permutation to the @data array with stride $stride.
permute-inverse(@data!, Int $stride! --> List)
This method applies the inverse of the current permutation to the @data array with stride $stride.
permute-complex64(Complex @data!, Int $stride! --> List)
This method applies the current permutation to the @data array array of Complex with stride $stride.
permute-complex64-inverse(Complex @data!, Int $stride! --> List)
This method applies the inverse of the current permutation to the @data array of Complex with stride $stride.
permute-complex32(Complex @data!, Int $stride! --> List)
This method applies the current permutation to the @data array array of Complex with stride $stride, trating the numbers as single precision floats.
permute-complex32-inverse(Complex @data!, Int $stride! --> List)
This method applies the inverse of the current permutation to the @data array of Complex with stride $stride, trating the numbers as single precision floats.
permute-vector(Math::Libgsl::Vector $v)
This method applies the permutation to a Vector object and returns the Vector object itself. As in the case of the Vector object, this method is available for all the supported data type, so we have
permute-vector-num32
permute-vector-int32
permute-vector-uint32
…and so on.
permute-vector-inv(Math::Libgsl::Vector $v)
This method applies the inverse permutation to a Vector object and returns the Vector object itself. As in the case of the Vector object, this method is available for all the supported data type, so we have
…and so on.
permute-matrix(Math::Libgsl::Matrix $m) This method applies the permutation to a Matrix object and returns the Matrix object itself. As in the case of the Matrix object, this method is available for all the supported data type, so we have
permute-matrix-num32
permute-matrix-int32
permute-matrix-uint32
…and so on.
write(Str $filename! --> Int)
This method writes the permutation data to a file.
read(Str $filename! --> Int)
This method reads the permutation data from a file. The permutation must be of the same size of the one to be read.
This method writes the permutation data to a file, using the format specifier.
fscanf(Str $filename!)
This method reads the permutation data from a file. The permutation must be of the same size of the one to be read.
multiply($dst! where * ~~ Math::Libgsl::Permutation, $p2! where * ~~ Math::Libgsl::Permutation)
This method combines the current permutation with the permutation $p2, stores the result into $dst and returns self.
to-canonical($dst! where * ~~ Math::Libgsl::Permutation)
This method computes the canonical form of the current permutation, stores the result into $dst and returns self.
to-linear($dst! where * ~~ Math::Libgsl::Permutation)
This method computes the linear form of the current permutation, stores the result into $dst and returns self.
inversions(--> Int)
This method counts the number of inversions in the current permutation.
linear-cycles(--> Int)
This method counts the number of cycles in the current permutation given in linear form.
canonical-cycles(--> Int)
This method counts the number of cycles in the current permutation given in canonical form.
C Library Documentation
For more details on libgsl see https://www.gnu.org/software/gsl/. The excellent C Library manual is available here https://www.gnu.org/software/gsl/doc/html/index.html, or here https://www.gnu.org/software/gsl/doc/latex/gsl-ref.pdf in PDF format.
Prerequisites
This module requires the libgsl library to be installed. Please follow the instructions below based on your platform:
Debian Linux and Ubuntu 20.04+
sudo apt install libgsl23 libgsl-dev libgslcblas0
That command will install libgslcblas0 as well, since it's used by the GSL.
Ubuntu 18.04
libgsl23 and libgslcblas0 have a missing symbol on Ubuntu 18.04. I solved the issue installing the Debian Buster version of those three libraries:
Installation
To install it using zef (a module management tool):
$ zef install Math::Libgsl::Permutation
AUTHOR
Fernando Santagata nando.santagata@gmail.com
COPYRIGHT AND LICENSE
Copyright 2020 Fernando Santagata
This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.