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37 /* This file is completely threadsafe - keep it that way! */
47 #include "gmx_fatal.h"
52 void do_rotate(double **a, int i, int j, int k, int l, double tau, double s)
57 a[i][j] = g - s * (h + g * tau);
58 a[k][l] = h + s * (g - h * tau);
61 void jacobi(double **a, int n, double d[], double **v, int *nrot)
65 double tresh, theta, tau, t, sm, s, h, g, c, *b, *z;
69 for (ip = 0; ip < n; ip++)
71 for (iq = 0; iq < n; iq++)
77 for (ip = 0; ip < n; ip++)
79 b[ip] = d[ip] = a[ip][ip];
83 for (i = 1; i <= 50; i++)
86 for (ip = 0; ip < n-1; ip++)
88 for (iq = ip+1; iq < n; iq++)
90 sm += fabs(a[ip][iq]);
101 tresh = 0.2*sm/(n*n);
107 for (ip = 0; ip < n-1; ip++)
109 for (iq = ip+1; iq < n; iq++)
111 g = 100.0*fabs(a[ip][iq]);
112 if (i > 4 && fabs(d[ip])+g == fabs(d[ip])
113 && fabs(d[iq])+g == fabs(d[iq]))
117 else if (fabs(a[ip][iq]) > tresh)
120 if (fabs(h)+g == fabs(h))
126 theta = 0.5*h/(a[ip][iq]);
127 t = 1.0/(fabs(theta)+sqrt(1.0+theta*theta));
142 for (j = 0; j < ip; j++)
144 do_rotate(a, j, ip, j, iq, tau, s);
146 for (j = ip+1; j < iq; j++)
148 do_rotate(a, ip, j, j, iq, tau, s);
150 for (j = iq+1; j < n; j++)
152 do_rotate(a, ip, j, iq, j, tau, s);
154 for (j = 0; j < n; j++)
156 do_rotate(v, j, ip, j, iq, tau, s);
162 for (ip = 0; ip < n; ip++)
169 gmx_fatal(FARGS, "Error: Too many iterations in routine JACOBI\n");
172 int m_inv_gen(real **m, int n, real **minv)
174 double **md, **v, *eig, tol, s;
175 int nzero, i, j, k, nrot;
178 for (i = 0; i < n; i++)
183 for (i = 0; i < n; i++)
188 for (i = 0; i < n; i++)
190 for (j = 0; j < n; j++)
197 for (i = 0; i < n; i++)
199 tol += fabs(md[i][i]);
203 jacobi(md, n, eig, v, &nrot);
206 for (i = 0; i < n; i++)
208 if (fabs(eig[i]) < tol)
219 for (i = 0; i < n; i++)
221 for (j = 0; j < n; j++)
224 for (k = 0; k < n; k++)
226 s += eig[k]*v[i][k]*v[j][k];
233 for (i = 0; i < n; i++)
238 for (i = 0; i < n; i++)