Performance monitoring (for the layered solver)

    This logs simple statistics available for the layered solver.

    event perfs (i += 1) {
      static FILE * fp = fopen ("perfs", "w");
      if (i == 0)
        fprintf (fp,
    	     "t dt mgp.i mgp.nrelax grid->tn perf.t perf.speed npe\n");
      fprintf (fp, "%g %g %d %d %ld %g %g %d\n", 
    	   t, dt,
    #if NH
    	   mgp.i, mgp.nrelax,
    	   0, 0,
    	   grid->tn*nl, perf.t, perf.speed*nl, npe());
      fflush (fp);

    If we have a display (and gnuplot works), a graph of the statistics is displayed and updated at regular intervals (10 seconds as defined in perfs.plot).

    event perf_plot (i = 10) {
      if (getenv ("DISPLAY"))
        popen ("gnuplot -e 'set term x11 noraise title perfs' "
    	   "$BASILISK/layered/perfs.plot 2> /dev/null "
    	   "& read dummy; kill $!", "w");

    See also