--- /dev/null
+## Copyright (C) 2003 Julius O. Smith III <jos@ccrma.stanford.edu>
+##
+## This program 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 3 of the License, or (at your option) any later
+## version.
+##
+## This program is distributed in the hope that it will be useful, but WITHOUT
+## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+## details.
+##
+## You should have received a copy of the GNU General Public License along with
+## this program; if not, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} freqs_plot (@var{w}, @var{h})
+## Plot the amplitude and phase of the vector @var{h}.
+##
+## @end deftypefn
+
+function freqs_plot(w,h)
+ n = length(w);
+ mag = 20*log10(abs(h));
+ phase = unwrap(arg(h));
+ maxmag = max(mag);
+
+ subplot(211);
+ plot(w, mag, ";Magnitude (dB);");
+ title('Frequency response plot by freqs');
+ axis("labely");
+ ylabel("dB");
+ xlabel("");
+ grid("on");
+ if (maxmag - min(mag) > 100) % make 100 a parameter?
+ axis([w(1), w(n), maxmag-100, maxmag]);
+ else
+ axis("autoy");
+ endif
+
+ subplot(212);
+ plot(w, phase/(2*pi), ";Phase (radians/2pi);");
+ axis("label");
+ title("");
+ grid("on");
+ axis("autoy");
+ xlabel("Frequency (rad/sec)");
+ ylabel("Cycles");
+ axis([w(1), w(n)]);
+endfunction