Re: Query regarding bsmatrix

[Felix Salfelder]

On Sat, Jul 22, 2023 at 04:09:52PM +0100, Jacob M via Gnucap-devel wrote:
> the real world.  Two questions: is there an easy way to print out the
> matrices?

Hi Jacob.

I once used variants of the mstat command (see below) to look at a matrix
nonzero pattern. Compile it, load it, "dc", "mstat" -- modify as needed, you
get the idea.

You will have noticed that Gnucap/bsmatrix only keeps track of the lowest index
used in a column, not of every single nonzero entry. I believe this needs
changing. I will investigate more when the time has come -- feel free to
experiment, I'm curious.

> CMK?

There is a plugin here [1] I once used for node reordering experiments. Not
sure which ordering it actually computes, still it shows how to apply a
permutation.

Generally, shuffling the input deck has a significant influence on the node
ordering. Try a few examples. Some orders work better than others, can you see
why?

cheers
felix

[1] https://codeberg.org/gnucap/gnucap-custom/src/branch/develop/c_cmk.cc

=== below
#include "m_matrix.h"
#include "c_comand.h"
#include "io_.h"
#include "globals.h"
#include "u_sim_data.h"
namespace{
class CMD_MSTAT: public CMD {
public:
  void do_it(CS& cmd, CARD_LIST* scope)
  {
    OMSTREAM out = IO::mstdout;

    CKT_BASE::_sim->init(scope);
    for(unsigned i=0; i <= _sim->_total_nodes; ++i){
      for(unsigned j=0; j <= _sim->_total_nodes; ++j){
        out << (bool) _sim->_aa.s(i,j);
      }
      out << "\n";
    }

    out.reset();
  }
} p5k;
DISPATCHER<CMD>::INSTALL d5k(&command_dispatcher, "mstat", &p5k);
}