# NAME

Math::SparseVector - Implements Sparse Vector Operations. The code is entirely borrowed from the existing Sparse::Vector v0.03 module on CPAN, and re-cast into a new namespace in order to introduce another module Math::SparseMatrix, which makes use of this module.

# USAGE

```
use Math::SparseVector;
# creating an empty sparse vector object
$spvec=Math::SparseVector->new;
# sets the value at index 12 to 5
$spvec->set(12,5);
# returns value at index 12
$value = $spvec->get(12);
# returns the indices of non-zero values in sorted order
@indices = $spvec->keys;
# returns 1 if the vector is empty and has no keys
if($spvec->isnull)
{
print "vector is null.\n";
}
else
{
print "vector is not null.\n";
}
# print sparse vector to stdout
$spvec->print;
# returns the string form of sparse vector
# same as print except the string is returned
# rather than displaying on stdout
$spvec->stringify;
# adds sparse vectors v1, v2 and stores
# result into v1
$v1->add($v2);
# adds binary equivalent of v2 to v1
$v1->binadd($v2);
# binary equivalnet treats all non-zero values
# as 1s
# increments the value at index 12
$spvec->incr(12);
# divides each vector entry by a given divisor 4
$spvec->div(4);
# returns norm of the vector
$spvec_norm = $spvec->norm;
# normalizes a sparse vector
$spvec->normalize;
# returns dot product of the 2 vectors
$dotprod = $v1->dot($v2);
# deallocates all entries
$spvec->free;
```

# ABSTRACT

Math::SparseVector is a Perl module that implements basic vector operations on sparse vectors. The code is entirely borrowed from the existing Sparse::Vector v0.03 module on CPAN, and re-cast into a new namespace in order to introduce another module Math::SparseMatrix, which makes use of this module.

# AUTHOR

Amruta Purandare, <amruta@cs.pitt.edu>

Ted Pedersen, <tpederse@d.umn.edu>

Mahesh Joshi, <joshi031@d.umn.edu>

# COPYRIGHT AND LICENSE

Copyright (c) 2006,

Amruta Purandare, University of Pittsburgh. amruta@cs.pitt.edu

Ted Pedersen, University of Minnesota, Duluth. tpederse@d.umn.edu

Mahesh Joshi, University of Minnesota, Duluth. joshi031@d.umn.edu

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to

The Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.