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# ex_fft.ppl
#
# The code in this file is part of Pyxplot
# <http://www.pyxplot.org.uk>
#
# Copyright (C) 2006-2012 Dominic Ford <coders@pyxplot.org.uk>
# 2008-2012 Ross Church
#
# $Id: ex_fft.ppl 1261 2012-07-11 21:38:05Z dcf21 $
#
# Pyxplot is free software; you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# You should have received a copy of the GNU General Public License along with
# Pyxplot; if not, write to the Free Software Foundation, Inc., 51 Franklin
# Street, Fifth Floor, Boston, MA 02110-1301, USA
# ----------------------------------------------------------------------------
# This script produces a figure for the Pyxplot Users' Guide
# Call common initialisation script
reset
# Main body of figure script
title = "ex_fft" ; load "examples/fig_init.ppl"
# BEGIN
set numerics complex
step(x) = tophat(x,0.5)
fft [-1:1:0.01] f() of step()
plot [-10:10] Re(f(x*1)) title texify("Re(f(x))"), sinc(pi*x)
# END
load "examples/fig_end.ppl"
# Main body of figure script
title = "ex_fft2" ; load "examples/fig_init.ppl"
# BEGIN
g(x) = f(x)**2
ifft [-50:49.5:0.5] h(x) of g(x)
plot [-2:2] Re(h(x))
# END
load "examples/fig_end.ppl"
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