How_can_I_save_time_in_solving?

The easiest way is to use the final result of the solution over a tile as your first guess as to the solution on the next tile.

> A thought crossed my mind - at present solvable parameters are being solved for separately from
> scratch in each tile. The reality, however, is that after we arrive at a solution for the first
> tile, things are unlikely
> to change much for succeeding tiles (unless a source has intrinsic
> time variability). So I would think that one could interate through
> all tiles more quickly if the final solution results for the just processed tile could be stored
> and provided as initial guesses for the
> tile that is just being loaded. is that possible?

It's not just possible, it's the default behavior. ;) I had explicitly disabled it to make the displays more "educational" -- otherwise you'd see no meaningful iterations past the first tile. This is controlled by the use_previous keyword to Parm; I set it from the reuse_solutions global variable defined at the top of the script. Set reuse_solutions=True and watch the speed improvement.