Pyxplot 
Examples  Box 
Using the colormap plot style with the fft command to draw a diffraction pattern (II) The Fourier transform of a rectangular box, plotted using the colormap plot style. Script# Definition of function representing a rectangular box box(x,y) = tophat(x,1) * tophat(y,0.5) # Take FFT of disk fft [40:40:0.1][40:40:0.1] fft() of box() w = unit(5*cm) set numerics complex set nogrid set key below set nocolorkey set sample grid 300x300 set size w square set multiplot set nodisplay # Plot realspace image plot [2:2][2:2] box(x,y) with colormap # Plot Fourierdomain image set origin w+unit(5*mm),0 set axis y right plot [2:2][2:2] abs(fft(x,y)) with colormap set display refresh
