GfsEventFilter

From Gerris

GfsEventFilter applies "exponential" filtering to a given variable.

The syntax in parameter files is as follows:

[ GfsEvent ] V TSCALE

where V is a variable and TSCALE is a strictly positive number. At every realisation of the event, variable V is replaced by (1 - a)*V + a*VF, where a = dt/TSCALE, dt is the timestep and VF is the filtered variable obtained by corner-value averaging.

Examples

• Coastally-trapped waves

  EventFilter { istep = 1 } U 4

  EventFilter { istep = 1 } V 4

• Coastally-trapped waves with adaptive refinement

  EventFilter { istep = 1 } U 4

  EventFilter { istep = 1 } V 4