/* dlaqge.f -- translated by f2c (version 20061008). You must link the resulting object file with libf2c: on Microsoft Windows system, link with libf2c.lib; on Linux or Unix systems, link with .../path/to/libf2c.a -lm or, if you install libf2c.a in a standard place, with -lf2c -lm -- in that order, at the end of the command line, as in cc *.o -lf2c -lm Source for libf2c is in /netlib/f2c/libf2c.zip, e.g., http://www.netlib.org/f2c/libf2c.zip */ #include "f2c.h" #include "blaswrap.h" /* Subroutine */ int dlaqge_(integer *m, integer *n, doublereal *a, integer * lda, doublereal *r__, doublereal *c__, doublereal *rowcnd, doublereal *colcnd, doublereal *amax, char *equed) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2; /* Local variables */ integer i__, j; doublereal cj, large, small; extern doublereal dlamch_(char *); /* -- LAPACK auxiliary routine (version 3.2) -- */ /* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ /* November 2006 */ /* .. Scalar Arguments .. */ /* .. */ /* .. Array Arguments .. */ /* .. */ /* 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. */ /* ===================================================================== */ /* .. Parameters .. */ /* .. */ /* .. Local Scalars .. */ /* .. */ /* .. External Functions .. */ /* .. */ /* .. Executable Statements .. */ /* Quick return if possible */ /* Parameter adjustments */ 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_ */