[FLASH-USERS] Tracking one cell value in time

[Klaus Weide]

On Tue, 18 Jun 2019, Sai Siva wrote:

> I want to track one particular cell value at all the times during the
> simulation.
> 
> I could able to get it from *ViSit--> Query options. *However this gives a
> desired cell value at *output times* only. As a result values at other
> times are unknown.
> 
> Is there any way in the FLASH code so that I can get one cell value at all
> the times.

There are some routines included with FLASH that should help you do this.
Have a look at

   Driver_computeCellLocations.F90

and, especially if you just want to write out certain values after each 
time step,

  IO_writeSingleCells.F90 .

The existing implementations are examples, they have some hardcoded values
(positions) in them and were originally written for 1 1D case. So you will
have to make some changes.

Note that Driver_computeCellLocations needs to be called collectively by 
all MPI ranks.

This may look overly complicated. The advantage is that you get a 
mechanism for tracking the same physical location across multiple changes 
of the grid during refinement and movement of blocks between ranks.

Klaus