opencv/3rdparty/lapack/slascl.c

325 lines
7.4 KiB
C

#include "clapack.h"
/* Subroutine */ int slascl_(char *type__, integer *kl, integer *ku, real *
cfrom, real *cto, integer *m, integer *n, real *a, integer *lda,
integer *info)
{
/* System generated locals */
integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5;
/* Local variables */
integer i__, j, k1, k2, k3, k4;
real mul, cto1;
logical done;
real ctoc;
extern logical lsame_(char *, char *);
integer itype;
real cfrom1;
extern doublereal slamch_(char *);
real cfromc;
extern /* Subroutine */ int xerbla_(char *, integer *);
real bignum, smlnum;
/* -- LAPACK auxiliary routine (version 3.1) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* SLASCL multiplies the M by N real matrix A by the real scalar */
/* CTO/CFROM. This is done without over/underflow as long as the final */
/* result CTO*A(I,J)/CFROM does not over/underflow. TYPE specifies that */
/* A may be full, upper triangular, lower triangular, upper Hessenberg, */
/* or banded. */
/* Arguments */
/* ========= */
/* TYPE (input) CHARACTER*1 */
/* TYPE indices the storage type of the input matrix. */
/* = 'G': A is a full matrix. */
/* = 'L': A is a lower triangular matrix. */
/* = 'U': A is an upper triangular matrix. */
/* = 'H': A is an upper Hessenberg matrix. */
/* = 'B': A is a symmetric band matrix with lower bandwidth KL */
/* and upper bandwidth KU and with the only the lower */
/* half stored. */
/* = 'Q': A is a symmetric band matrix with lower bandwidth KL */
/* and upper bandwidth KU and with the only the upper */
/* half stored. */
/* = 'Z': A is a band matrix with lower bandwidth KL and upper */
/* bandwidth KU. */
/* KL (input) INTEGER */
/* The lower bandwidth of A. Referenced only if TYPE = 'B', */
/* 'Q' or 'Z'. */
/* KU (input) INTEGER */
/* The upper bandwidth of A. Referenced only if TYPE = 'B', */
/* 'Q' or 'Z'. */
/* CFROM (input) REAL */
/* CTO (input) REAL */
/* The matrix A is multiplied by CTO/CFROM. A(I,J) is computed */
/* without over/underflow if the final result CTO*A(I,J)/CFROM */
/* can be represented without over/underflow. CFROM must be */
/* nonzero. */
/* 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) REAL array, dimension (LDA,N) */
/* The matrix to be multiplied by CTO/CFROM. See TYPE for the */
/* storage type. */
/* LDA (input) INTEGER */
/* The leading dimension of the array A. LDA >= max(1,M). */
/* INFO (output) INTEGER */
/* 0 - successful exit */
/* <0 - if INFO = -i, the i-th argument had an illegal value. */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Executable Statements .. */
/* Test the input arguments */
/* Parameter adjustments */
a_dim1 = *lda;
a_offset = 1 + a_dim1;
a -= a_offset;
/* Function Body */
*info = 0;
if (lsame_(type__, "G")) {
itype = 0;
} else if (lsame_(type__, "L")) {
itype = 1;
} else if (lsame_(type__, "U")) {
itype = 2;
} else if (lsame_(type__, "H")) {
itype = 3;
} else if (lsame_(type__, "B")) {
itype = 4;
} else if (lsame_(type__, "Q")) {
itype = 5;
} else if (lsame_(type__, "Z")) {
itype = 6;
} else {
itype = -1;
}
if (itype == -1) {
*info = -1;
} else if (*cfrom == 0.f) {
*info = -4;
} else if (*m < 0) {
*info = -6;
} else if (*n < 0 || itype == 4 && *n != *m || itype == 5 && *n != *m) {
*info = -7;
} else if (itype <= 3 && *lda < max(1,*m)) {
*info = -9;
} else if (itype >= 4) {
/* Computing MAX */
i__1 = *m - 1;
if (*kl < 0 || *kl > max(i__1,0)) {
*info = -2;
} else /* if(complicated condition) */ {
/* Computing MAX */
i__1 = *n - 1;
if (*ku < 0 || *ku > max(i__1,0) || (itype == 4 || itype == 5) &&
*kl != *ku) {
*info = -3;
} else if (itype == 4 && *lda < *kl + 1 || itype == 5 && *lda < *
ku + 1 || itype == 6 && *lda < (*kl << 1) + *ku + 1) {
*info = -9;
}
}
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("SLASCL", &i__1);
return 0;
}
/* Quick return if possible */
if (*n == 0 || *m == 0) {
return 0;
}
/* Get machine parameters */
smlnum = slamch_("S");
bignum = 1.f / smlnum;
cfromc = *cfrom;
ctoc = *cto;
L10:
cfrom1 = cfromc * smlnum;
cto1 = ctoc / bignum;
if (dabs(cfrom1) > dabs(ctoc) && ctoc != 0.f) {
mul = smlnum;
done = FALSE_;
cfromc = cfrom1;
} else if (dabs(cto1) > dabs(cfromc)) {
mul = bignum;
done = FALSE_;
ctoc = cto1;
} else {
mul = ctoc / cfromc;
done = TRUE_;
}
if (itype == 0) {
/* Full matrix */
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] *= mul;
/* L20: */
}
/* L30: */
}
} else if (itype == 1) {
/* Lower triangular matrix */
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = *m;
for (i__ = j; i__ <= i__2; ++i__) {
a[i__ + j * a_dim1] *= mul;
/* L40: */
}
/* L50: */
}
} else if (itype == 2) {
/* Upper triangular matrix */
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = min(j,*m);
for (i__ = 1; i__ <= i__2; ++i__) {
a[i__ + j * a_dim1] *= mul;
/* L60: */
}
/* L70: */
}
} else if (itype == 3) {
/* Upper Hessenberg matrix */
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
/* Computing MIN */
i__3 = j + 1;
i__2 = min(i__3,*m);
for (i__ = 1; i__ <= i__2; ++i__) {
a[i__ + j * a_dim1] *= mul;
/* L80: */
}
/* L90: */
}
} else if (itype == 4) {
/* Lower half of a symmetric band matrix */
k3 = *kl + 1;
k4 = *n + 1;
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
/* Computing MIN */
i__3 = k3, i__4 = k4 - j;
i__2 = min(i__3,i__4);
for (i__ = 1; i__ <= i__2; ++i__) {
a[i__ + j * a_dim1] *= mul;
/* L100: */
}
/* L110: */
}
} else if (itype == 5) {
/* Upper half of a symmetric band matrix */
k1 = *ku + 2;
k3 = *ku + 1;
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
/* Computing MAX */
i__2 = k1 - j;
i__3 = k3;
for (i__ = max(i__2,1); i__ <= i__3; ++i__) {
a[i__ + j * a_dim1] *= mul;
/* L120: */
}
/* L130: */
}
} else if (itype == 6) {
/* Band matrix */
k1 = *kl + *ku + 2;
k2 = *kl + 1;
k3 = (*kl << 1) + *ku + 1;
k4 = *kl + *ku + 1 + *m;
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
/* Computing MAX */
i__3 = k1 - j;
/* Computing MIN */
i__4 = k3, i__5 = k4 - j;
i__2 = min(i__4,i__5);
for (i__ = max(i__3,k2); i__ <= i__2; ++i__) {
a[i__ + j * a_dim1] *= mul;
/* L140: */
}
/* L150: */
}
}
if (! done) {
goto L10;
}
return 0;
/* End of SLASCL */
} /* slascl_ */