Sparse sub access

This package allows to retrieve and assign values of sparse matrix in one shot.

The indexes must be provided in (row,column) form. Functions in this package are programmed with care so no overflow of linear index is used with large-size matrix. I try to design an engine of automatic selection algorithms so as to provide a good run time performance across various cases. I'm not sure it's worth the effort, but my experience shows that it is easy to mess with the performance when non-appropriate method is using in sparse manipulation. This package does not warranty for best performance, but it just has a modest pretension to prevent user to use bad algorithm. For a better customize solution, a calibration is required on the specific
computer by running this command: spcalib('auto')