NetBSD/sys/dev/wscons/mra.c

119 lines
3.4 KiB
C

/* $NetBSD: mra.c,v 1.6 2014/03/14 05:03:19 khorben Exp $ */
/*
* Copyright (c) 1999 Shin Takemura All rights reserved.
* Copyright (c) 1999 PocketBSD Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: mra.c,v 1.6 2014/03/14 05:03:19 khorben Exp $");
#include <sys/param.h>
#include <sys/systm.h>
extern int mra_Y_AX1_BX2_C(const int *, int,
const int *, int, const int *, int, int, int,
int *, int *, int *);
/*
* multiple regression analysis
* Y = AX1 + BX2 + C
*/
int
mra_Y_AX1_BX2_C(const int *y, int ys,
const int *x1, int x1s, const int *x2, int x2s,
int n, int scale,
int *a, int *b, int *c)
{
int i;
int64_t X1a, X2a, Ya;
int64_t X1X1s, X2X2s, X1X2s;
int64_t YYs, X1Ys, X2Ys;
int64_t S11, S22, S12;
// int64_t SYY;
int64_t S1Y, S2Y;
int64_t A, B, C, M;
#define AA(p, s, i) (*((const int *)(((const char *)(p)) + (s) * (i))))
#define X1(i) AA(x1, x1s, i)
#define X2(i) AA(x2, x2s, i)
#define Y(i) AA(y, ys, i)
/*
* get avarage and sum
*/
X1a = 0; X2a = 0; Ya = 0;
X1X1s = 0; X2X2s = 0; X1X2s = 0;
X1Ys = 0; X2Ys = 0; YYs = 0;
for (i = 0; i < n; i++) {
X1a += X1(i);
X2a += X2(i);
Ya += Y(i);
X1X1s += X1(i) * X1(i);
X2X2s += X2(i) * X2(i);
X1X2s += X1(i) * X2(i);
X1Ys += X1(i) * Y(i);
X2Ys += X2(i) * Y(i);
YYs += Y(i) * Y(i);
}
X1a /= n; X2a /= n; Ya /= n;
S11 = X1X1s - n * X1a * X1a;
S22 = X2X2s - n * X2a * X2a;
S12 = X1X2s - n * X1a * X2a;
// SYY = YYs - n * Ya * Ya;
S1Y = X1Ys - n * X1a * Ya;
S2Y = X2Ys - n * X2a * Ya;
#if 0
printf("X1a=%d X2a=%d Ya=%d\n", (int)X1a, (int)X2a, (int)Ya);
printf("X1X1s=%d X2X2s=%d X1X2s=%d\n", (int)X1X1s, (int)X2X2s, (int)X1X2s);
printf("X1Ys=%d X2Ys=%d YYs=%d\n", (int)X1Ys, (int)X2Ys, (int)YYs);
printf("S11=%d S22=%d S12=%d\n", (int)S11, (int)S22, (int)S12);
printf("SYY=%d S1Y=%d S2Y=%d\n", (int)SYY, (int)S1Y, (int)S2Y);
#endif
M = (S11 * S22 - S12 * S12);
if (M == 0) {
/* error */
return -1;
}
A = (S1Y * S22 - S2Y * S12) * scale / M;
B = (S2Y * S11 - S1Y * S12) * scale / M;
C = Ya - (A * X1a + B * X2a) / scale;
#if 0
printf("A=%d B=%d C=%d\n", (int)A, (int)B, (int)C);
#endif
*a = A;
*b = B;
*c = C;
return (0);
}