text: %SJGET_EXAMPLE a demo for SJget.
  %   This example script gets the index file of the SJSU Singular matrix collection,
  %   and then loads in all symmetric non-binary matrices, in increasing order of
  %   number of rows in the matrix.
  %
  %   Example:
  %       type SJget_example ; % to see an example of how to use SJget
  %
  %   See also SJget, SJweb, SJgrep.
  
  %   Derived from the UFget toolbox on March 18, 2008.
  %   Copyright 2007, Tim Davis, University of Florida.
  
  %   modified by L. Foster 09/17/2008
  
  type SJget_example ;
  
  index = SJget ;
  % find all symmetric matrices that are not binary,
  % have at least 4000 column and have a gap in the singular
  % values at the numerical rank of at least 1000
  f = find (index.numerical_symmetry == 1 & ~index.isBinary & ...
      index.ncols >= 4000 & index.gap >= 1000 );
  % sort by the dimension of the numerical null space
  [y, j] = sort (index.ncols (f) - index.numrank (f) ) ;
  f = f (j) ;
  
  for i = f
      fprintf ('Loading %s%s%s, please wait ...\n', ...
  	index.Group {i}, filesep, index.Name {i}) ;
      Problem = SJget (i,index) ;
      %display the problem structure
      disp (Problem) ;
      % display a plot of the singular values
      SJplot(Problem) ;
      shg
      disp(' ')
      disp(['dim. of numerical null space = ', ...
          num2str(index.ncols (i) - index.numrank (i))]);
      disp(' ')
      pause(1)
      %display the web page with matrix details
      SJweb (i) ;
      pause(1)
  end
  
  