% SPOK : checks the validity of a MATLAB sparse matrix.
%
% This function is of little use for those using purely M-files.  It is
% extremely useful for those who write mexFunctions that return sparse matrices
% to MATLAB.  A MATLAB sparse matrix is stored in compressed-column form, where
% each column is stored as a list of entries with their row indices and their
% corresponding numerical values.  Row indices must appear in ascending order,
% and no explicitly zero numerical entries can appear.  Constructing a valid
% sparse matrix in a mexFunction can be difficult.  This function will help you
% to know if you've done that correctly.
%
% Files
%   spok         - checks if a sparse matrix is OK
%   spok_install - compiles and installs the SPOK mexFunction
%   spok_test    - installs and tests SPOK
%
% Example
%
%   load west0479
%   A = west0479 ;
%   spok (A)                % double sparse
%   spok (A + 1i*A)         % complex sparse
%   spok (A > .5)           % logical sparse

% Copyright 2008, Tim Davis, University of Florida
