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45 #include "gromacs/legacyheaders/gmx_fatal.h"
46 #include "gromacs/legacyheaders/smalloc.h"
47 #include "gromacs/legacyheaders/vec.h"
49 #include "gmx_lapack.h"
51 double **alloc_matrix(int n, int m)
56 /* There's always time for more pointer arithmetic! */
57 /* This is necessary in order to be able to work with LAPACK */
60 for (i = 1; (i < n); i++)
67 void free_matrix(double **a)
76 void matrix_multiply(FILE *fp, int n, int m, double **x, double **y, double **z)
83 fprintf(fp, "Multiplying %d x %d matrix with a %d x %d matrix\n",
88 for (i = 0; (i < n); i++)
90 for (j = 0; (j < m); j++)
92 fprintf(fp, " %7g", x[i][j]);
98 for (i = 0; (i < m); i++)
100 for (j = 0; (j < m); j++)
103 for (k = 0; (k < n); k++)
105 z[i][j] += x[k][i]*y[j][k];
111 static void dump_matrix(FILE *fp, const char *title, int n, double **a)
116 fprintf(fp, "%s\n", title);
117 for (i = 0; (i < n); i++)
120 for (j = 0; (j < n); j++)
122 fprintf(fp, " %8.2f", a[i][j]);
126 fprintf(fp, "Prod a[i][i] = %g\n", d);
129 int matrix_invert(FILE *fp, int n, double **a)
131 int i, j, m, lda, *ipiv, lwork, info;
132 double **test = NULL, **id, *work;
137 fprintf(fp, "Inverting %d square matrix\n", n);
138 test = alloc_matrix(n, n);
139 for (i = 0; (i < n); i++)
141 for (j = 0; (j < n); j++)
143 test[i][j] = a[i][j];
146 dump_matrix(fp, "before inversion", n, a);
154 F77_FUNC(dgetrf, DGETRF) (&n, &m, a[0], &lda, ipiv, &info);
158 dump_matrix(fp, "after dgetrf", n, a);
165 F77_FUNC(dgetri, DGETRI) (&n, a[0], &lda, ipiv, work, &lwork, &info);
169 dump_matrix(fp, "after dgetri", n, a);
180 id = alloc_matrix(n, n);
181 matrix_multiply(fp, n, n, test, a, id);
182 dump_matrix(fp, "And here is the product of A and Ainv", n, id);
193 double multi_regression(FILE *fp, int nrow, double *y, int ncol,
194 double **xx, double *a0)
196 int row, niter, i, j;
197 double ax, chi2, **a, **at, **ata, *atx;
199 a = alloc_matrix(nrow, ncol);
200 at = alloc_matrix(ncol, nrow);
201 ata = alloc_matrix(ncol, ncol);
202 for (i = 0; (i < nrow); i++)
204 for (j = 0; (j < ncol); j++)
206 at[j][i] = a[i][j] = xx[j][i];
209 matrix_multiply(fp, nrow, ncol, a, at, ata);
210 if ((row = matrix_invert(fp, ncol, ata)) != 0)
212 gmx_fatal(FARGS, "Matrix inversion failed. Incorrect row = %d.\nThis probably indicates that you do not have sufficient data points, or that some parameters are linearly dependent.",
217 for (i = 0; (i < ncol); i++)
220 for (j = 0; (j < nrow); j++)
222 atx[i] += at[i][j]*y[j];
225 for (i = 0; (i < ncol); i++)
228 for (j = 0; (j < ncol); j++)
230 a0[i] += ata[i][j]*atx[j];
234 for (j = 0; (j < nrow); j++)
237 for (i = 0; (i < ncol); i++)
241 chi2 += sqr(y[j]-ax);