compare simulating data to real data

[juticekitty]

Dear Professor:
I have real economy's data, after using Dynare to simulate my model ,I want to compare the standard deviation of real data and simulating data,but I don't know how I deal with the real data so that the standard deviation of real data and simulating data are comparable to each other ,should the real data be H-P flitered or logged?
I should very much appreciate your sending me some instruction.
trulyyours,