Syntax:
fix ID grid/check N outflag keyword arg ...
outside arg = yes or no
Examples:
fix 1 grid/check 100 error
Description:
Check if particles are inside the grid cell they are supposed to be, based on their current coordinates. This is useful as a debugging check to insure that no particles have been assigned to the incorrect grid cell during the particle move stage of the SPARTA timestepping algorithm.
The check is performed once every N timesteps. Particles not inside the correct grid cell are counted and the value of the count can be monitored (see below). A value of 0 is "correct", meaning that no particle was found outside its assigned grid cell.
If the outside keyword is set to yes, then a check for particles inside explicit or implicit surfaces is also performed. If a particle is in a grid cell with surface elements and the particle is "inside" the surfaces, then the error count is incremented.
If the outflag setting is error, SPARTA will print an error and stop if it finds a particle in an incorrect grid cell or inside the surface elements. For warn, it will print a warning message and continue. For silent, it will print no message, but the count of such occurrences can be monitored as described below, e.g. by outputting the value with the stats command.
IMPORTANT NOTE: Use of outside yes can be expensive if the check is performed frequently (e.g. every step).
Restart, output info:
No information about this fix is written to binary restart files.
This fix computes a global scalar which can be accessed by various output commands. The scalar is the count of how many particles were not in the correct grid cell. The count is cummulative over all the timesteps the check was performed since the start of the run. It is initialized to zero each time a run is performed.
Styles with a kk suffix are functionally the same as the corresponding style without the suffix. They have been optimized to run faster, depending on your available hardware, as discussed in the Accelerating SPARTA section of the manual. The accelerated styles take the same arguments and should produce the same results, except for different random number, round-off and precision issues.
These accelerated styles are part of the KOKKOS package. They are only enabled if SPARTA was built with that package. See the Making SPARTA section for more info.
You can specify the accelerated styles explicitly in your input script by including their suffix, or you can use the -suffix command-line switch when you invoke SPARTA, or you can use the suffix command in your input script.
See the Accelerating SPARTA section of the manual for more instructions on how to use the accelerated styles effectively.
Restrictions: none
Related commands: none
Default:
The option default is outside = no.