1 | /* $NetBSD: mra.c,v 1.6 2014/03/14 05:03:19 khorben Exp $ */ |
2 | |
3 | /* |
4 | * Copyright (c) 1999 Shin Takemura All rights reserved. |
5 | * Copyright (c) 1999 PocketBSD Project. All rights reserved. |
6 | * |
7 | * Redistribution and use in source and binary forms, with or without |
8 | * modification, are permitted provided that the following conditions |
9 | * are met: |
10 | * 1. Redistributions of source code must retain the above copyright |
11 | * notice, this list of conditions and the following disclaimer. |
12 | * 2. Redistributions in binary form must reproduce the above copyright |
13 | * notice, this list of conditions and the following disclaimer in the |
14 | * documentation and/or other materials provided with the distribution. |
15 | * |
16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
17 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
18 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
19 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
20 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
21 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
22 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
23 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
24 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
25 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
26 | * SUCH DAMAGE. |
27 | * |
28 | */ |
29 | |
30 | #include <sys/cdefs.h> |
31 | __KERNEL_RCSID(0, "$NetBSD: mra.c,v 1.6 2014/03/14 05:03:19 khorben Exp $" ); |
32 | |
33 | #include <sys/param.h> |
34 | #include <sys/systm.h> |
35 | |
36 | extern int mra_Y_AX1_BX2_C(const int *, int, |
37 | const int *, int, const int *, int, int, int, |
38 | int *, int *, int *); |
39 | |
40 | /* |
41 | * multiple regression analysis |
42 | * Y = AX1 + BX2 + C |
43 | */ |
44 | int |
45 | mra_Y_AX1_BX2_C(const int *y, int ys, |
46 | const int *x1, int x1s, const int *x2, int x2s, |
47 | int n, int scale, |
48 | int *a, int *b, int *c) |
49 | { |
50 | int i; |
51 | int64_t X1a, X2a, Ya; |
52 | int64_t X1X1s, X2X2s, X1X2s; |
53 | int64_t YYs, X1Ys, X2Ys; |
54 | int64_t S11, S22, S12; |
55 | // int64_t SYY; |
56 | int64_t S1Y, S2Y; |
57 | int64_t A, B, C, M; |
58 | #define AA(p, s, i) (*((const int *)(((const char *)(p)) + (s) * (i)))) |
59 | #define X1(i) AA(x1, x1s, i) |
60 | #define X2(i) AA(x2, x2s, i) |
61 | #define Y(i) AA(y, ys, i) |
62 | |
63 | /* |
64 | * get avarage and sum |
65 | */ |
66 | X1a = 0; X2a = 0; Ya = 0; |
67 | X1X1s = 0; X2X2s = 0; X1X2s = 0; |
68 | X1Ys = 0; X2Ys = 0; YYs = 0; |
69 | for (i = 0; i < n; i++) { |
70 | X1a += X1(i); |
71 | X2a += X2(i); |
72 | Ya += Y(i); |
73 | |
74 | X1X1s += X1(i) * X1(i); |
75 | X2X2s += X2(i) * X2(i); |
76 | X1X2s += X1(i) * X2(i); |
77 | |
78 | X1Ys += X1(i) * Y(i); |
79 | X2Ys += X2(i) * Y(i); |
80 | YYs += Y(i) * Y(i); |
81 | } |
82 | X1a /= n; X2a /= n; Ya /= n; |
83 | |
84 | S11 = X1X1s - n * X1a * X1a; |
85 | S22 = X2X2s - n * X2a * X2a; |
86 | S12 = X1X2s - n * X1a * X2a; |
87 | |
88 | // SYY = YYs - n * Ya * Ya; |
89 | S1Y = X1Ys - n * X1a * Ya; |
90 | S2Y = X2Ys - n * X2a * Ya; |
91 | |
92 | #if 0 |
93 | printf("X1a=%d X2a=%d Ya=%d\n" , (int)X1a, (int)X2a, (int)Ya); |
94 | printf("X1X1s=%d X2X2s=%d X1X2s=%d\n" , (int)X1X1s, (int)X2X2s, (int)X1X2s); |
95 | printf("X1Ys=%d X2Ys=%d YYs=%d\n" , (int)X1Ys, (int)X2Ys, (int)YYs); |
96 | printf("S11=%d S22=%d S12=%d\n" , (int)S11, (int)S22, (int)S12); |
97 | printf("SYY=%d S1Y=%d S2Y=%d\n" , (int)SYY, (int)S1Y, (int)S2Y); |
98 | #endif |
99 | |
100 | M = (S11 * S22 - S12 * S12); |
101 | if (M == 0) { |
102 | /* error */ |
103 | return -1; |
104 | } |
105 | |
106 | A = (S1Y * S22 - S2Y * S12) * scale / M; |
107 | B = (S2Y * S11 - S1Y * S12) * scale / M; |
108 | C = Ya - (A * X1a + B * X2a) / scale; |
109 | |
110 | #if 0 |
111 | printf("A=%d B=%d C=%d\n" , (int)A, (int)B, (int)C); |
112 | #endif |
113 | *a = A; |
114 | *b = B; |
115 | *c = C; |
116 | |
117 | return (0); |
118 | } |
119 | |