Time averaged field calculations

[bhogan1984]

Hi all, In order to calculate a time averaged value for the electric field I am varying the phase of the applied wave and averaging the field. This works fine using the S:GetEField({x,y,z}) command however when using the S:GetLayerZIntegral(layer, {x, y}) command the computed field does not change with phase of incoming wave.

Has anyone come across this before?

https://web.stanford.edu/group/fan/S4/lua_api.html says that this command does not return a time averaged value.