thanks Rick, but I am looking for a VBA code
that link presents theory and an excel file without the code

"Rick Rothstein (MVP - VB)" wrote:

does any body have a VB code for an inverse fourier trasnform?

I'm not familiar with it myself, but according to this link...

http://electron9.phys.utk.edu/optics...m6/fourier.htm

it is part of the Analysis ToolPak (see 4th paragraph).

Rick