What is the story with these Wisdom files, extension fftw that mysteriously pop up once in awhile? Googled it - I see FFTW is a program, but I have NO idea what they're talking about on the various sites I've been to.

Driving me a little batty because I don't know what they are, would like just to just toss them out, but not sure if that might mess something up. One such file just now appeared in the folder for my current Sonar project.

Any info?