#include "blaswrap.h" #include "f2c.h" /* Subroutine */ int dlaqge_(integer *m, integer *n, doublereal *a, integer * lda, doublereal *r__, doublereal *c__, doublereal *rowcnd, doublereal *colcnd, doublereal *amax, char *equed) { /* -- LAPACK auxiliary routine (version 3.1) -- Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. November 2006 Purpose ======= DLAQGE equilibrates a general M by N matrix A using the row and column scaling factors in the vectors R and C. Arguments ========= M (input) INTEGER The number of rows of the matrix A. M >= 0. N (input) INTEGER The number of columns of the matrix A. N >= 0. A (input/output) DOUBLE PRECISION array, dimension (LDA,N) On entry, the M by N matrix A. On exit, the equilibrated matrix. See EQUED for the form of the equilibrated matrix. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(M,1). R (input) DOUBLE PRECISION array, dimension (M) The row scale factors for A. C (input) DOUBLE PRECISION array, dimension (N) The column scale factors for A. ROWCND (input) DOUBLE PRECISION Ratio of the smallest R(i) to the largest R(i). COLCND (input) DOUBLE PRECISION Ratio of the smallest C(i) to the largest C(i). AMAX (input) DOUBLE PRECISION Absolute value of largest matrix entry. EQUED (output) CHARACTER*1 Specifies the form of equilibration that was done. = 'N': No equilibration = 'R': Row equilibration, i.e., A has been premultiplied by diag(R). = 'C': Column equilibration, i.e., A has been postmultiplied by diag(C). = 'B': Both row and column equilibration, i.e., A has been replaced by diag(R) * A * diag(C). Internal Parameters =================== THRESH is a threshold value used to decide if row or column scaling should be done based on the ratio of the row or column scaling factors. If ROWCND < THRESH, row scaling is done, and if COLCND < THRESH, column scaling is done. LARGE and SMALL are threshold values used to decide if row scaling should be done based on the absolute size of the largest matrix element. If AMAX > LARGE or AMAX < SMALL, row scaling is done. ===================================================================== Quick return if possible Parameter adjustments */ /* System generated locals */ integer a_dim1, a_offset, i__1, i__2; /* Local variables */ static integer i__, j; static doublereal cj, large, small; extern doublereal dlamch_(char *); a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --r__; --c__; /* Function Body */ if (*m <= 0 || *n <= 0) { *(unsigned char *)equed = 'N'; return 0; } /* Initialize LARGE and SMALL. */ small = dlamch_("Safe minimum") / dlamch_("Precision"); large = 1. / small; if (*rowcnd >= .1 && *amax >= small && *amax <= large) { /* No row scaling */ if (*colcnd >= .1) { /* No column scaling */ *(unsigned char *)equed = 'N'; } else { /* Column scaling */ i__1 = *n; for (j = 1; j <= i__1; ++j) { cj = c__[j]; i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { a[i__ + j * a_dim1] = cj * a[i__ + j * a_dim1]; /* L10: */ } /* L20: */ } *(unsigned char *)equed = 'C'; } } else if (*colcnd >= .1) { /* Row scaling, no column scaling */ i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { a[i__ + j * a_dim1] = r__[i__] * a[i__ + j * a_dim1]; /* L30: */ } /* L40: */ } *(unsigned char *)equed = 'R'; } else { /* Row and column scaling */ i__1 = *n; for (j = 1; j <= i__1; ++j) { cj = c__[j]; i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { a[i__ + j * a_dim1] = cj * r__[i__] * a[i__ + j * a_dim1]; /* L50: */ } /* L60: */ } *(unsigned char *)equed = 'B'; } return 0; /* End of DLAQGE */ } /* dlaqge_ */