NAME

Math::GSL::Vector - Functions concerning vectors

SYNOPSIS

    use Math::GSL::Vector qw/:all/;
    my $vec1 = Math::GSL::Vector->new([1, 7, 94, 15 ]);
    my $vec2 = $vec1 * 5; 
    my $vec3 = Math::GSL::Vector>new(10);   # 10 element zero vector 

    # set the element at index 1 to 9
    # and the element at index 3 to 8
    $vec3->set([ 1, 3 ], [ 9, 8 ]);   

    my @vec = $vec2->as_list;               # return elements as Perl list

    my $dot_product = $vec1 * $vec2;
    my $length      = $vec2->length;
    my $first       = $vec1->get(0);

Objected Oriented Interface to GSL Math::GSL::Vector

Math::GSL::Vector->new()

Creates a new Vector of the given size.

    my $vector = Math::GSL::Matrix->new(3);

You can also create and set directly the values of the vector like this :

   my $vector = Math::GSL::Vector->new([2,4,1]);

raw()

Get the underlying GSL vector object created by SWIG, useful for using gsl_vector_* functions which do not have an OO counterpart.

    my $vector    = Math::GSL::vector->new(3);
    my $gsl_vector = $vector->raw;
    my $stuff      = gsl_vector_get($gsl_vector, 1);

min()

Returns the minimum value contained in the vector.

   my $vector = Math::GSL::Vector->new([2,4,1]);
   my $minimum = $vector->min;

max()

Returns the minimum value contained in the vector.

   my $vector = Math::GSL::Vector->new([2,4,1]);
   my $maximum = $vector->max;

length()

Returns the number of elements contained in the vector.

   my $vector = Math::GSL::Vector->new([2,4,1]);
   my $length = $vector->length;

as_list()

Gets the content of a Math::GSL::Vector object as a Perl list.

    my $vector = Math::GSL::vector->new(3);
    ...
    my @values = $vector->as_list;

get()

Gets the value of an of a Math::GSL::Vector object.

    my $vector = Math::GSL::vector->new(3);
    ...
    my @values = $vector->get(2);

You can also enter an array of indices to receive their corresponding values:

    my $vector = Math::GSL::vector->new(3);
    ...
    my @values = $vector->get([0,2]);

set()

Sets values of an of a Math::GSL::Vector object.

    my $vector = Math::GSL::vector->new(3);
    $vector->set([1,2], [8,23]);

This sets the second and third value to 8 and 23.

DESCRIPTION

Here is a list of all the functions included in this module :

gsl_vector_alloc($x) - create a vector of size $x

gsl_vector_calloc($x) - create a vector of size $x and initializes all the elements of the vector to zero

gsl_vector_alloc_from_block

gsl_vector_alloc_from_vector

gsl_vector_free($v) - free a previously allocated vector $v

gsl_vector_view_array

gsl_vector_view_array_with_stride

gsl_vector_const_view_array_with_stride

gsl_vector_subvector($v, $offset, $n) - return a vector_view type which contains a subvector of $v, with a size of $size, starting from the $offset position

gsl_vector_subvector_with_stride($v, $offset, $stride, $size) - return a vector_view type which contains a subvector of $v, with a size of $size, starting from the $offset position and with a $stride step between each element of $v

gsl_vector_const_subvector

gsl_vector_get($v, $i) - return the $i-th element of a vector $v

gsl_vector_set($v, $i, $x) - return the vector $v with his $i-th element set to $x

gsl_vector_ptr

gsl_vector_const_ptr

gsl_vector_set_zero($v) - set all the elements of $v to 0

gsl_vector_set_all($v, $x) - set all the elements of $v to $x

gsl_vector_set_basis($v, $i) - set all the elements of $v to 0 except for the $i-th element which is set to 1 and return 0 if the operation succeded, 1 otherwise.

gsl_vector_fread($file, $v) - This function reads into the vector $v from the open stream $file opened with fopen in binary format. The vector $v must be preallocated with the correct length since the function uses the size of $v to determine how many bytes to read. The return value is 0 for success and 1 if there was a problem reading from the file.

gsl_vector_fwrite($file, $v) - This function writes the elements of the vector $v to the stream $file opened with fopen in binary format. The return value is 0 for success and 1 if there was a problem writing to the file. Since the data is written in the native binary format it may not be portable between different architectures.

gsl_vector_fscanf($file, $v) This function reads formatted data from the stream $file opened with fopen into the vector $v. The vector $v must be preallocated with the correct length since the function uses the size of $v to determine how many numbers to read. The function returns 0 for success and 1 if there was a problem reading from the file.

gsl_vector_fprintf($file, $v, $format) -This function writes the elements of the vector $v line-by-line to the stream $file opened with fopen using the format specifier format, which should be one of the "%g", "%e" or "%f" formats for floating point numbers and "%d" for integers. The function returns 0 for success and 1 if there was a problem writing to the file.

gsl_vector_memcpy($dest, $src) - This function copies the elements of the vector $src into the vector $dest and return 0 if the opertaion succeded, 1 otherwise. The two vectors must have the same length.

gsl_vector_reverse($v) - reverse the order of the elements of the vector $v and return 0 if the opertaion succeded, 1 otherwise

gsl_vector_swap($v, $v2) - swap the values of the vectors $v and $v2 and return 0 if the opertaion succeded, 1 otherwise

gsl_vector_swap_elements($v, $i, $j) - permute the elements at position $i and $j in the vector $v and return 0 if the operation succeded, 1 otherwise.

gsl_vector_max($v) - return the maximum value in the vector $v

gsl_vector_min($v) - return the minimum value in the vector $v

gsl_vector_minmax($v) - return two values, the first is the minimum value in the vector $v and the second is the maximum value.

gsl_vector_max_index($v) - return the position of the maximum value in the vector $v

gsl_vector_min_index($v) - return the position of the minimum value in the vector $v

gsl_vector_minmax_index - return two values, the first is the position of the minimum value in the vector $v and the second is the position of the maximum value.

gsl_vector_add($v, $v2) - add the elements of $v2 to the elements of $v, the two vectors must have the same lenght and return 0 if the operation succeded, 1 otherwise.

gsl_vector_sub($v, $v2) - substract the elements of $v2 from the elements of $v, the two vectors must have the same lenght and return 0 if the operation succeded, 1 otherwise.

gsl_vector_mul($v, $v2) - multiply the elements of $v by the elements of $v2, the two vectors must have the same lenght and return 0 if the operation succeded, 1 otherwise.

gsl_vector_div($v, $v2) - divides the elements of $v by the elements of $v2, the two vectors must have the same lenght and return 0 if the operation succeded, 1 otherwise.

gsl_vector_scale($v, $x) - multiplty the elements of the vector $v by a constant $x and return 0 if the operation succeded, 1 otherwise.

gsl_vector_add_constant($v, $x) - add a constant $x to the elements of the vector $v and return 0 if the operation succeded, 1 otherwise.

gsl_vector_isnull($v) - verify if all the elements of the vector $v are null, return 0 if it's the case, 1 otherwise.

gsl_vector_ispos($v) - verify if all the elements of the vector $v are positive, return 0 if it's the case, 1 otherwise.

gsl_vector_isneg($v) - verify if all the elements of the vector $v are negative, return 0 if it's the case, 1 otherwise.

gsl_vector_isnonneg($v) - verify if all the elements the vector $v are not negative, return 0 if it's the case, 1 otherwise.

You have to add the functions you want to use inside the qw /put_funtion_here / with spaces between each function. You can also write use Math::GSL::Complex qw/:all/ to use all avaible functions of the module.

Precision on the vector_view type : every modification you'll make on a vector_view will also modify the original vector. For example, the following code will zero the even elements of the vector $v of length $size, while leaving the odd elements untouched :

$v_even= gsl_vector_subvector_with_stride ($v, 0, 2, $size/2);

gsl_vector_set_zero ($v_even->{vector});

For more informations on the functions, we refer you to the GSL offcial documentation: http://www.gnu.org/software/gsl/manual/html_node/ Tip : search on google: site:http://www.gnu.org/software/gsl/manual/html_node/ name_of_the_function_you_want

EXAMPLES

 use Math::GSL::Vector qw/:all/;
 print "We'll create this vector : [0,1,4,9,16] \n";
 my $vector = Math::GSL::Vector->new([0,1,4,9,16]);
 my ($min, $max) = gsl_vector_minmax_index($vector->raw);
 print "We then check the index value of the maximum and minimum values of the vector. \n";
 print "The index of the maximum should be 4 and we received $max \n";
 print "The index of the minimum should be 0 and we received $min \n";
 print "We'll then swap the first and the third elements of the vector \n";
 gsl_vector_swap_elements($vector->raw, 0, 3);
 my @got = $vector->as_list;
 print "The vector should now be like this : [9,1,4,0,16] \n";
 print "and we received : [";
 for (my $element=0; $element<4; $element++) {
 print "$got[$element],"; }
 print "$got[4]] \n"; 

AUTHOR

Jonathan Leto <jonathan@leto.net> and Thierry Moisan <thierry.moisan@gmail.com>

COPYRIGHT AND LICENSE

Copyright (C) 2008 Jonathan Leto and Thierry Moisan

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

cpanm Math::GSL

perl -MCPAN -e shell
install Math::GSL