/* claqgb.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 claqgb_(integer *m, integer *n, integer *kl, integer *ku, complex *ab, integer *ldab, real *r__, real *c__, real *rowcnd, real *colcnd, real *amax, char *equed) { /* System generated locals */ integer ab_dim1, ab_offset, i__1, i__2, i__3, i__4, i__5, i__6; real r__1; complex q__1; /* Local variables */ integer i__, j; real cj, large, small; extern doublereal slamch_(char *); /* -- LAPACK auxiliary routine (version 3.2) -- */ /* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ /* November 2006 */ /* .. Scalar Arguments .. */ /* .. */ /* .. Array Arguments .. */ /* .. */ /* Purpose */ /* ======= */ /* CLAQGB equilibrates a general M by N band matrix A with KL */ /* subdiagonals and KU superdiagonals using the row and 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. */ /* KL (input) INTEGER */ /* The number of subdiagonals within the band of A. KL >= 0. */ /* KU (input) INTEGER */ /* The number of superdiagonals within the band of A. KU >= 0. */ /* AB (input/output) COMPLEX array, dimension (LDAB,N) */ /* On entry, the matrix A in band storage, in rows 1 to KL+KU+1. */ /* The j-th column of A is stored in the j-th column of the */ /* array AB as follows: */ /* AB(ku+1+i-j,j) = A(i,j) for max(1,j-ku)<=i<=min(m,j+kl) */ /* On exit, the equilibrated matrix, in the same storage format */ /* as A. See EQUED for the form of the equilibrated matrix. */ /* LDAB (input) INTEGER */ /* The leading dimension of the array AB. LDA >= KL+KU+1. */ /* R (input) REAL array, dimension (M) */ /* The row scale factors for A. */ /* C (input) REAL array, dimension (N) */ /* The column scale factors for A. */ /* ROWCND (input) REAL */ /* Ratio of the smallest R(i) to the largest R(i). */ /* COLCND (input) REAL */ /* Ratio of the smallest C(i) to the largest C(i). */ /* AMAX (input) REAL */ /* 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 .. */ /* .. */ /* .. Intrinsic Functions .. */ /* .. */ /* .. Executable Statements .. */ /* Quick return if possible */ /* Parameter adjustments */ ab_dim1 = *ldab; ab_offset = 1 + ab_dim1; ab -= ab_offset; --r__; --c__; /* Function Body */ if (*m <= 0 || *n <= 0) { *(unsigned char *)equed = 'N'; return 0; } /* Initialize LARGE and SMALL. */ small = slamch_("Safe minimum") / slamch_("Precision"); large = 1.f / small; if (*rowcnd >= .1f && *amax >= small && *amax <= large) { /* No row scaling */ if (*colcnd >= .1f) { /* No column scaling */ *(unsigned char *)equed = 'N'; } else { /* Column scaling */ i__1 = *n; for (j = 1; j <= i__1; ++j) { cj = c__[j]; /* Computing MAX */ i__2 = 1, i__3 = j - *ku; /* Computing MIN */ i__5 = *m, i__6 = j + *kl; i__4 = min(i__5,i__6); for (i__ = max(i__2,i__3); i__ <= i__4; ++i__) { i__2 = *ku + 1 + i__ - j + j * ab_dim1; i__3 = *ku + 1 + i__ - j + j * ab_dim1; q__1.r = cj * ab[i__3].r, q__1.i = cj * ab[i__3].i; ab[i__2].r = q__1.r, ab[i__2].i = q__1.i; /* L10: */ } /* L20: */ } *(unsigned char *)equed = 'C'; } } else if (*colcnd >= .1f) { /* Row scaling, no column scaling */ i__1 = *n; for (j = 1; j <= i__1; ++j) { /* Computing MAX */ i__4 = 1, i__2 = j - *ku; /* Computing MIN */ i__5 = *m, i__6 = j + *kl; i__3 = min(i__5,i__6); for (i__ = max(i__4,i__2); i__ <= i__3; ++i__) { i__4 = *ku + 1 + i__ - j + j * ab_dim1; i__2 = i__; i__5 = *ku + 1 + i__ - j + j * ab_dim1; q__1.r = r__[i__2] * ab[i__5].r, q__1.i = r__[i__2] * ab[i__5] .i; ab[i__4].r = q__1.r, ab[i__4].i = q__1.i; /* L30: */ } /* L40: */ } *(unsigned char *)equed = 'R'; } else { /* Row and column scaling */ i__1 = *n; for (j = 1; j <= i__1; ++j) { cj = c__[j]; /* Computing MAX */ i__3 = 1, i__4 = j - *ku; /* Computing MIN */ i__5 = *m, i__6 = j + *kl; i__2 = min(i__5,i__6); for (i__ = max(i__3,i__4); i__ <= i__2; ++i__) { i__3 = *ku + 1 + i__ - j + j * ab_dim1; r__1 = cj * r__[i__]; i__4 = *ku + 1 + i__ - j + j * ab_dim1; q__1.r = r__1 * ab[i__4].r, q__1.i = r__1 * ab[i__4].i; ab[i__3].r = q__1.r, ab[i__3].i = q__1.i; /* L50: */ } /* L60: */ } *(unsigned char *)equed = 'B'; } return 0; /* End of CLAQGB */ } /* claqgb_ */