| 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 | |