NAME

       PDL::CCS - Sparse N-dimensional PDLs with compressed column storage

SYNOPSIS

        use PDL;
        use PDL::CCS;

        ## ... stuff happens ...

DESCRIPTION

       PDL::CCS is now just a wrapper package which pulls in a number of submodules.  See the
       documentation of the respective modules for details.

   Modules
       PDL::CCS::Nd
           Perl class for representing large sparse N-dimensional numeric structures using sorted
           index vector-vectors and a flat vector of non-missing values.  Supports a subset of
           the perl-side PDL API.

       PDL::CCS::Compat
           Backwards-compatibility module for Harwell-Boeing compressed row- or column-storage.

       PDL::CCS::Functions
           Some useful generic pure-perl functions for dealing directly with CCS-, CRS-, and
           index-encoded PDLs.

       PDL::CCS::Utils
           Low-level generic PDL::PP utilities for Harwell-Boeing encoding and decoding
           "pointers" along arbitrary dimensions of a sparse PDL given an index list.

       PDL::CCS::Ops
           Low-level generic PDL::PP utilities for blockwise alignment of pairs of sparse index-
           encoded PDLs, useful for implementing binary operations.

       PDL::CCS::Ufunc
           Various low-level ufunc (accumulator) utilities for index-encoded PDLs.

       PDL::CCS::MatrixOps
           Low-level generic PDL::PP utilities for matrix operations on index-encoded PDLs.

       PDL::CCS::IO::FastRaw
           PDL::IO::FastRaw wrappers for PDL::CCS::Nd objects.

ACKNOWLEDGEMENTS

       Perl by Larry Wall.

       PDL by Karl Glazebrook, Tuomas J. Lukka, Christian Soeller, and others.

       Original inspiration and algorithms from the SVDLIBC C library by Douglas Rohde; which is
       itself based on SVDPACKC by Michael Berry, Theresa Do, Gavin O'Brien, Vijay Krishna and
       Sowmini Varadhan.

KNOWN BUGS

       •   PDL::CCS::Nd supports only a subset of the PDL API (i.e. is not really a PDL).

       •   Binary operations via alignment only work correctly when missing values are
           annihilators.

       •   Misleading module name: PDL::CCS::Nd objects actually use a native COO (full
           coordinate list) format rather than CRS (compressed row storage) or CCS (compressed
           column storage); see
           <https://en.wikipedia.org/wiki/Sparse_matrix#Coordinate_list_(COO)> for a discussion.

AUTHOR

       Bryan Jurish <moocow@cpan.org>

   Copyright Policy
       Copyright (C) 2005-2022 by Bryan Jurish. All rights reserved.

       This package is free software, and entirely without warranty.  You may redistribute it
       and/or modify it under the same terms as Perl itself.

SEE ALSO

       perl(1), PDL(3perl), PDL::CCS::Nd(3perl), PDL::SVDLIBC(3perl),
       <https://en.wikipedia.org/wiki/Sparse_matrix>.