1 /*************************************************************************/
2 /* */
3 /* Language Technologies Institute */
4 /* Carnegie Mellon University */
5 /* Copyright (c) 2001 */
6 /* All Rights Reserved. */
7 /* */
8 /* Permission is hereby granted, free of charge, to use and distribute */
9 /* this software and its documentation without restriction, including */
10 /* without limitation the rights to use, copy, modify, merge, publish, */
11 /* distribute, sublicense, and/or sell copies of this work, and to */
12 /* permit persons to whom this work is furnished to do so, subject to */
13 /* the following conditions: */
14 /* 1. The code must retain the above copyright notice, this list of */
15 /* conditions and the following disclaimer. */
16 /* 2. Any modifications must be clearly marked as such. */
17 /* 3. Original authors' names are not deleted. */
18 /* 4. The authors' names are not used to endorse or promote products */
19 /* derived from this software without specific prior written */
20 /* permission. */
21 /* */
22 /* CARNEGIE MELLON UNIVERSITY AND THE CONTRIBUTORS TO THIS WORK */
23 /* DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING */
24 /* ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT */
25 /* SHALL CARNEGIE MELLON UNIVERSITY NOR THE CONTRIBUTORS BE LIABLE */
26 /* FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES */
27 /* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN */
28 /* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, */
29 /* ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF */
30 /* THIS SOFTWARE. */
31 /* */
32 /*************************************************************************/
33 /* Author: Alan W Black (awb@cs.cmu.edu) */
34 /* Date: November 2001 */
35 /*************************************************************************/
36 /* */
37 /* sufficient statitsics */
38 /* */
39 /*************************************************************************/
40
41 #include "cst_alloc.h"
42 #include "cst_ss.h"
43 #include "cst_math.h"
44
new_ss()45 cst_ss *new_ss()
46 {
47 cst_ss *ss = cst_alloc(cst_ss,1);
48 return ss;
49 }
50
delete_ss(cst_ss * ss)51 void delete_ss(cst_ss *ss)
52 {
53 cst_free(ss);
54 }
55
ss_reset(cst_ss * ss)56 void ss_reset(cst_ss *ss)
57 {
58 ss->num_samples = 0;
59 ss->sum = 0;
60 ss->sumx = 0;
61 }
62
ss_mean(cst_ss * ss)63 double ss_mean(cst_ss *ss)
64 {
65 if (ss->num_samples > 0)
66 return ss->sum/ss->num_samples;
67 else
68 return 0;
69 }
70
ss_variance(cst_ss * ss)71 double ss_variance(cst_ss *ss)
72 {
73 if (ss->num_samples > 1)
74 return ((ss->num_samples*ss->sumx)-(ss->sum*ss->sum))/
75 (ss->num_samples*(ss->num_samples-1));
76 else
77 return 0;
78 }
79
ss_stddev(cst_ss * ss)80 double ss_stddev(cst_ss *ss)
81 {
82 return sqrt(ss_variance(ss));
83 }
84
ss_cummulate(cst_ss * ss,double a)85 void ss_cummulate(cst_ss *ss,double a)
86 {
87 ss->sum += a;
88 ss->sumx += a*a;
89 ss->num_samples++;
90 }
91
ss_cummulate_n(cst_ss * ss,double a,double count)92 void ss_cummulate_n(cst_ss *ss,double a, double count)
93 {
94 ss->sum += a*count;
95 ss->sumx += (a*a)*count;
96 ss->num_samples += count;
97 }
98
99