diff options
Diffstat (limited to 'gr-utils/octave/plot_freq_response_db.m')
| -rw-r--r-- | gr-utils/octave/plot_freq_response_db.m | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/gr-utils/octave/plot_freq_response_db.m b/gr-utils/octave/plot_freq_response_db.m new file mode 100644 index 0000000000..10ce7d6e17 --- /dev/null +++ b/gr-utils/octave/plot_freq_response_db.m @@ -0,0 +1,39 @@ +# +# Copyright 2001 Free Software Foundation, Inc. +# +# This file is part of GNU Radio +# +# GNU Radio 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, or (at your option) +# any later version. +# +# GNU Radio 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 GNU Radio; see the file COPYING. If not, write to +# the Free Software Foundation, Inc., 51 Franklin Street, +# Boston, MA 02110-1301, USA. +# + +function plot_freq_response_db (b,...) + if (nargin == 1) + ## Response of an FIR filter + a = 1; + elseif (nargin == 2) + ## response of an IIR filter + a = va_arg (); + endif + + [H,w] = freqz (b,a); + + grid; + xlabel ('Normalized Frequency (Fs == 1)'); + ylabel ('Magnitude Squared (dB)'); + abs = abs(H); +# plot (w/(2*pi), 20 * log10 (abs/max(abs))); + plot (w/(2*pi), 20 * log10 (abs)); +endfunction |