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annotate spandsp-0.0.6pre17/tests/awgn_tests.c @ 4:26cd8f1ef0b1

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import spandsp-0.0.6pre17
author Peter Meerwald <pmeerw@cosy.sbg.ac.at>
date Fri, 25 Jun 2010 15:50:58 +0200
parents
children
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4
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
1 /*
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
2 * SpanDSP - a series of DSP components for telephony
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
3 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
4 * awgn_tests.c
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
5 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
6 * Written by Steve Underwood <steveu@coppice.org>
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
7 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
8 * Copyright (C) 2001 Steve Underwood
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
9 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
10 * All rights reserved.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
11 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
12 * This program is free software; you can redistribute it and/or modify
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
13 * it under the terms of the GNU General Public License version 2, as
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
14 * published by the Free Software Foundation.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
15 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
16 * This program is distributed in the hope that it will be useful,
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
19 * GNU General Public License for more details.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
20 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
21 * You should have received a copy of the GNU General Public License
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
22 * along with this program; if not, write to the Free Software
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
24 *
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
25 * $Id: awgn_tests.c,v 1.18 2008/11/30 12:38:27 steveu Exp $
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
26 */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
27
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
28 /*! \page awgn_tests_page AWGN tests
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
29 \section awgn_tests_page_sec_1 What does it do?
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
30 */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
31
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
32 #if defined(HAVE_CONFIG_H)
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
33 #include "config.h"
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
34 #endif
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
35
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
36 #include <stdlib.h>
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
37 #include <stdio.h>
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
38 #include <string.h>
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
39
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
40 //#if defined(WITH_SPANDSP_INTERNALS)
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
41 #define SPANDSP_EXPOSE_INTERNAL_STRUCTURES
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
42 //#endif
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
43
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
44 #include "spandsp.h"
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
45
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
46 #if !defined(M_PI)
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
47 # define M_PI 3.14159265358979323846 /* pi */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
48 #endif
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
49
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
50 #define OUT_FILE_NAME "awgn.wav"
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
51
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
52 /* Some simple sanity tests for the Gaussian noise generation routines */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
53
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
54 int main (int argc, char *argv[])
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
55 {
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
56 int i;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
57 int j;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
58 int clip_high;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
59 int clip_low;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
60 int total_samples;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
61 int idum = 1234567;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
62 int16_t value;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
63 double total;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
64 double x;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
65 double p;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
66 double o;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
67 double error;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
68 int bins[65536];
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
69 awgn_state_t noise_source;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
70
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
71 /* Generate noise at several RMS levels between -50dBm and 0dBm. Noise is
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
72 generated for a large number of samples (1,000,000), and the RMS value
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
73 of the noise is calculated along the way. If the resulting level is
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
74 close to the requested RMS level, at least the scaling of the noise
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
75 should be Ok. At high level some clipping may distort the result a
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
76 little. */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
77 for (j = -50; j <= 0; j += 5)
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
78 {
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
79 clip_high = 0;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
80 clip_low = 0;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
81 total = 0.0;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
82 awgn_init_dbm0(&noise_source, idum, (float) j);
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
83 total_samples = 1000000;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
84 for (i = 0; i < total_samples; i++)
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
85 {
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
86 value = awgn(&noise_source);
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
87 if (value == 32767)
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
88 clip_high++;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
89 else if (value == -32768)
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
90 clip_low++;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
91 total += ((double) value)*((double) value);
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
92 }
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
93 error = 100.0*(1.0 - sqrt(total/total_samples)/noise_source.rms);
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
94 printf("RMS = %.3f (expected %d) %.2f%% error [clipped samples %d+%d]\n",
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
95 log10(sqrt(total/total_samples)/32768.0)*20.0 + DBM0_MAX_POWER,
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
96 j,
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
97 error,
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
98 clip_low,
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
99 clip_high);
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
100 /* We don't check the result at 0dBm0, as there will definitely be a lot of error due to clipping */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
101 if (j < 0 && fabs(error) > 0.2)
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
102 {
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
103 printf("Test failed.\n");
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
104 exit(2);
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
105 }
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
106 }
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
107 /* Now look at the statistical spread of the results, by collecting data in
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
108 bins from a large number of samples. Use a fairly high noise level, but
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
109 low enough to avoid significant clipping. Use the Gaussian model to
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
110 predict the real probability, and present the results for graphing. */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
111 memset(bins, 0, sizeof(bins));
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
112 clip_high = 0;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
113 clip_low = 0;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
114 awgn_init_dbm0(&noise_source, idum, -15);
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
115 total_samples = 10000000;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
116 for (i = 0; i < total_samples; i++)
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
117 {
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
118 value = awgn(&noise_source);
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
119 if (value == 32767)
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
120 clip_high++;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
121 else if (value == -32768)
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
122 clip_low++;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
123 bins[value + 32768]++;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
124 }
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
125 o = noise_source.rms;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
126 for (i = 0; i < 65536 - 10; i++)
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
127 {
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
128 x = i - 32768;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
129 /* Find the real probability for this bin */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
130 p = (1.0/(o*sqrt(2.0*M_PI)))*exp(-(x*x)/(2.0*o*o));
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
131 /* Now do a little smoothing on the real data to get a reasonably
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
132 steady answer */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
133 x = 0;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
134 for (j = 0; j < 10; j++)
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
135 x += bins[i + j];
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
136 x /= 10.0;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
137 x /= total_samples;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
138 /* Now send it out for graphing. */
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
139 printf("%6d %.7f %.7f\n", i - 32768, x, p);
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
140 }
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
141
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
142 printf("Tests passed.\n");
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
143 return 0;
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
144 }
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
145 /*- End of function --------------------------------------------------------*/
26cd8f1ef0b1 import spandsp-0.0.6pre17
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
diff changeset
146 /*- End of file ------------------------------------------------------------*/

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