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| Rev | Author | Line No. | Line |
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| 204 | chris | 1 | /******************************************************* |
| 2 | * |
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| 3 | * Author: Shinsaku Hiura, Hirokazu Kato |
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| 4 | * |
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| 5 | * shinsaku@sys.es.osaka-u.ac.jp |
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| 6 | * kato@sys.im.hiroshima-cu.ac.jp |
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| 7 | * |
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| 8 | * Revision: 2.1 |
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| 9 | * Date: 99/07/16 |
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| 10 | * |
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| 11 | *******************************************************/ |
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| 12 | #include <stdio.h> |
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| 13 | #include <math.h> |
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| 14 | #include <AR/matrix.h> |
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| 15 | |||
| 16 | static double *minv( double *ap, int dimen, int rowa ); |
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| 17 | |||
| 18 | int arMatrixSelfInv(ARMat *m) |
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| 19 | { |
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| 20 | if(minv(m->m, m->row, m->row) == NULL) return -1; |
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| 21 | |||
| 22 | return 0; |
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| 23 | } |
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| 24 | |||
| 25 | |||
| 26 | /********************************/ |
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| 27 | /* */ |
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| 28 | /* MATRIX inverse function */ |
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| 29 | /* */ |
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| 30 | /********************************/ |
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| 31 | static double *minv( double *ap, int dimen, int rowa ) |
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| 32 | { |
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| 33 | double *wap, *wcp, *wbp;/* work pointer */ |
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| 34 | int i,j,n,ip,nwork; |
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| 35 | int nos[50]; |
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| 36 | double epsl; |
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| 37 | double p,pbuf,work; |
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| 38 | double fabs(); |
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| 39 | |||
| 40 | epsl = 1.0e-10; /* Threshold value */ |
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| 41 | |||
| 42 | switch (dimen) { |
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| 43 | case (0): return(NULL); /* check size */ |
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| 44 | case (1): *ap = 1.0 / (*ap); |
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| 45 | return(ap); /* 1 dimension */ |
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| 46 | } |
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| 47 | |||
| 48 | for(n = 0; n < dimen ; n++) |
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| 49 | nos[n] = n; |
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| 50 | |||
| 51 | for(n = 0; n < dimen ; n++) { |
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| 52 | wcp = ap + n * rowa; |
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| 53 | |||
| 54 | for(i = n, wap = wcp, p = 0.0; i < dimen ; i++, wap += rowa) |
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| 55 | if( p < ( pbuf = fabs(*wap)) ) { |
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| 56 | p = pbuf; |
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| 57 | ip = i; |
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| 58 | } |
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| 59 | if (p <= epsl) |
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| 60 | return(NULL); |
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| 61 | |||
| 62 | nwork = nos[ip]; |
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| 63 | nos[ip] = nos[n]; |
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| 64 | nos[n] = nwork; |
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| 65 | |||
| 66 | for(j = 0, wap = ap + ip * rowa, wbp = wcp; j < dimen ; j++) { |
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| 67 | work = *wap; |
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| 68 | *wap++ = *wbp; |
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| 69 | *wbp++ = work; |
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| 70 | } |
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| 71 | |||
| 72 | for(j = 1, wap = wcp, work = *wcp; j < dimen ; j++, wap++) |
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| 73 | *wap = *(wap + 1) / work; |
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| 74 | *wap = 1.0 / work; |
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| 75 | |||
| 76 | for(i = 0; i < dimen ; i++) { |
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| 77 | if(i != n) { |
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| 78 | wap = ap + i * rowa; |
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| 79 | for(j = 1, wbp = wcp, work = *wap; |
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| 80 | j < dimen ; j++, wap++, wbp++) |
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| 81 | *wap = *(wap + 1) - work * (*wbp); |
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| 82 | *wap = -work * (*wbp); |
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| 83 | } |
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| 84 | } |
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| 85 | } |
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| 86 | |||
| 87 | for(n = 0; n < dimen ; n++) { |
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| 88 | for(j = n; j < dimen ; j++) |
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| 89 | if( nos[j] == n) break; |
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| 90 | nos[j] = nos[n]; |
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| 91 | for(i = 0, wap = ap + j, wbp = ap + n; i < dimen ; |
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| 92 | i++, wap += rowa, wbp += rowa) { |
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| 93 | work = *wap; |
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| 94 | *wap = *wbp; |
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| 95 | *wbp = work; |
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| 96 | } |
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| 97 | } |
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| 98 | return(ap); |
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| 99 | } |