This section configures the time_step and dump frequency settings and must be present in the input file. It accepts the following data:

  • dt, float, default = 0.0
  • ndump, integer, default = 0
  • dump_start, integer, default = 0

dt specifies the time step in simulation units. It must be different from 0.0.

ndump specifies the number of iterations between any diagnostic or restart file dumps. If set to 0 all dumps will be turned off. This value will be multiplied by each of the ndump_fac_* parameters in the restart and diagnostic sections.

dump_start specifies the number of iterations after which to begin any diagnostic file dumps. Note this does not affect restart file dumps.

Here’s an example of a time_step section, using a 0.0032 time step and doing dumps every 200 time steps, where the first two dump events will be ignored due to the way the dump_start parameter is set.

time_step 
{
  dt = 0.0032,
  ndump = 200,
  dump_start = 500,
}