Mercurial > octave-nkf

comparison scripts/signal/freqz_plot.m @ 6448:2110cc251779

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
[project @ 2007-03-24 02:47:36 by jwe]
author jwe
date Sat, 24 Mar 2007 02:47:36 +0000
parents ddfe04062467
children a8105a726e68
comparison
equal deleted inserted replaced
6447:3f79532415b5 6448:2110cc251779
22 ## Plot the pass band, stop band and phase response of @var{h}. 22 ## Plot the pass band, stop band and phase response of @var{h}.
23 ## @end deftypefn 23 ## @end deftypefn
24 24
25 ## Author: Paul Kienzle <pkienzle@users.sf.net> 25 ## Author: Paul Kienzle <pkienzle@users.sf.net>
26 26
27 function freqz_plot(w,h) 27 function freqz_plot (w, h)
28 28
29 n = length (w); 29 n = length (w);
30 30
31 ## ## exclude zero-frequency 31 ## ## exclude zero-frequency
32 ## h = h (2 : length (h)); 32 ## h = h (2 : length (h));
35 35
36 mag = 20 * log10 (abs (h)); 36 mag = 20 * log10 (abs (h));
37 phase = unwrap (arg (h)); 37 phase = unwrap (arg (h));
38 maxmag = max (mag); 38 maxmag = max (mag);
39 39
40 unwind_protect 40 subplot (3, 1, 1);
41 plot (w, mag, ";Pass band (dB);");
42 grid ("on");
43 axis ([w(1), w(n), maxmag-3, maxmag], "labely");
41 44
42 ## Protect graph state. 45 subplot (3, 1, 2);
46 plot (w, mag, ";Stop band (dB);");
47 grid ("on");
48 if (maxmag - min (mag) > 100)
49 axis ([w(1), w(n), maxmag-100, maxmag], "labely");
50 else
51 axis ("autoy", "labely");
52 endif
43 53
44 replot_state = automatic_replot; 54 subplot (3, 1, 3);
45 automatic_replot(0); 55 plot (w, phase*360/(2*pi), ";Phase (degrees);");
46 56 grid ("on");
47 subplot (311); 57 xlabel ("Frequency");
48 __gnuplot_set__ lmargin 10; 58 axis ([w(1), w(n)], "autoy", "label");
49 axis ("labely");
50 xlabel ("");
51 grid ("on");
52 axis ([ w(1), w(n), maxmag-3, maxmag ]);
53 plot (w, mag, ";Pass band (dB);");
54
55 subplot (312);
56 axis ("labely");
57 title ("");
58 xlabel ("");
59 __gnuplot_set__ tmargin 0;
60 grid ("on");
61 if (maxmag - min (mag) > 100)
62 axis ([ w(1), w(n), maxmag-100, maxmag ]);
63 else
64 axis ("autoy");
65 endif
66 plot (w, mag, ";Stop band (dB);");
67
68 subplot (313);
69 axis ("label");
70 title ("");
71 grid ("on");
72 axis ("autoy");
73 xlabel ("Frequency");
74 axis ([ w(1), w(n) ]);
75 plot (w, phase*360/(2*pi), ";Phase (degrees);");
76
77 unwind_protect_cleanup
78
79 ## Restore graph state.
80
81 ## FIXME -- if automatic_replot is non-zero, this will
82 ## mess up the graph, however if we don't do it here then the user
83 ## will have to do it themselves.
84
85 grid ("off");
86 axis ("auto", "label");
87 __gnuplot_set__ lmargin;
88 __gnuplot_set__ tmargin;
89 oneplot ();
90
91 automatic_replot(replot_state);
92
93 end_unwind_protect
94 59
95 endfunction 60 endfunction