One thing I always missed in desktop calculators is RPN
Reverse Polish Notation.   Finally a real calculator for RPN users.
Get "galculator" from
 http://dag.wieers.com/rpm/packages/?M=D 
one of 4,000 apps.  Some have dependency problems with a little work can be 
resolved.

I have been working on a scheme to analyze wind data and have been using 
fft from "Numerical Recipes".   Need to change a lot of data from time domain 
to frequency domain for power spectral density.   What am I looking for ?
Currently a C5 and the characteristic CF6 engine whine and then other 
atmospheric phenomena.

Larry Linder