function f=freqscale(N,m,fs)
% freqscale - return frequency scale for FFT analysis
%
%    FREQSCALE(N,m,fs): frequency scale for the first m bins of an N-pt FT, 
%			with a sampling rate=fs, defaults to 1.

if nargin<2, fs=1; end
f=fs*(0:(m-1))/N;
