ds1= sin( dindgen(1000)/10 )
ds2= fft( ds1 )
ds3= magnitude( ds2 )

# this is a wav file of a whistler at Jupiter
file= 'http://www-pw.physics.uiowa.edu/~jbf/spaceTheory/sounds/_jwhist/jwhist.half.wav'
ds4= getDataSet( file )
ds5= fftWindow( ds4, 128 )
result= ds5