460 lines
13 KiB
C
460 lines
13 KiB
C
/* -- translated by f2c (version 20240504).
|
|
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"
|
|
|
|
/* > \brief \b DSYR2K
|
|
|
|
=========== DOCUMENTATION ===========
|
|
|
|
Online html documentation available at
|
|
http://www.netlib.org/lapack/explore-html/
|
|
|
|
Definition:
|
|
===========
|
|
|
|
SUBROUTINE DSYR2K(UPLO,TRANS,N,K,ALPHA,A,LDA,B,LDB,BETA,C,LDC)
|
|
|
|
DOUBLE PRECISION ALPHA,BETA
|
|
INTEGER K,LDA,LDB,LDC,N
|
|
CHARACTER TRANS,UPLO
|
|
DOUBLE PRECISION A(LDA,*),B(LDB,*),C(LDC,*)
|
|
|
|
|
|
> \par Purpose:
|
|
=============
|
|
>
|
|
> \verbatim
|
|
>
|
|
> DSYR2K performs one of the symmetric rank 2k operations
|
|
>
|
|
> C := alpha*A*B**T + alpha*B*A**T + beta*C,
|
|
>
|
|
> or
|
|
>
|
|
> C := alpha*A**T*B + alpha*B**T*A + beta*C,
|
|
>
|
|
> where alpha and beta are scalars, C is an n by n symmetric matrix
|
|
> and A and B are n by k matrices in the first case and k by n
|
|
> matrices in the second case.
|
|
> \endverbatim
|
|
|
|
Arguments:
|
|
==========
|
|
|
|
> \param[in] UPLO
|
|
> \verbatim
|
|
> UPLO is CHARACTER*1
|
|
> On entry, UPLO specifies whether the upper or lower
|
|
> triangular part of the array C is to be referenced as
|
|
> follows:
|
|
>
|
|
> UPLO = 'U' or 'u' Only the upper triangular part of C
|
|
> is to be referenced.
|
|
>
|
|
> UPLO = 'L' or 'l' Only the lower triangular part of C
|
|
> is to be referenced.
|
|
> \endverbatim
|
|
>
|
|
> \param[in] TRANS
|
|
> \verbatim
|
|
> TRANS is CHARACTER*1
|
|
> On entry, TRANS specifies the operation to be performed as
|
|
> follows:
|
|
>
|
|
> TRANS = 'N' or 'n' C := alpha*A*B**T + alpha*B*A**T +
|
|
> beta*C.
|
|
>
|
|
> TRANS = 'T' or 't' C := alpha*A**T*B + alpha*B**T*A +
|
|
> beta*C.
|
|
>
|
|
> TRANS = 'C' or 'c' C := alpha*A**T*B + alpha*B**T*A +
|
|
> beta*C.
|
|
> \endverbatim
|
|
>
|
|
> \param[in] N
|
|
> \verbatim
|
|
> N is INTEGER
|
|
> On entry, N specifies the order of the matrix C. N must be
|
|
> at least zero.
|
|
> \endverbatim
|
|
>
|
|
> \param[in] K
|
|
> \verbatim
|
|
> K is INTEGER
|
|
> On entry with TRANS = 'N' or 'n', K specifies the number
|
|
> of columns of the matrices A and B, and on entry with
|
|
> TRANS = 'T' or 't' or 'C' or 'c', K specifies the number
|
|
> of rows of the matrices A and B. K must be at least zero.
|
|
> \endverbatim
|
|
>
|
|
> \param[in] ALPHA
|
|
> \verbatim
|
|
> ALPHA is DOUBLE PRECISION.
|
|
> On entry, ALPHA specifies the scalar alpha.
|
|
> \endverbatim
|
|
>
|
|
> \param[in] A
|
|
> \verbatim
|
|
> A is DOUBLE PRECISION array, dimension ( LDA, ka ), where ka is
|
|
> k when TRANS = 'N' or 'n', and is n otherwise.
|
|
> Before entry with TRANS = 'N' or 'n', the leading n by k
|
|
> part of the array A must contain the matrix A, otherwise
|
|
> the leading k by n part of the array A must contain the
|
|
> matrix A.
|
|
> \endverbatim
|
|
>
|
|
> \param[in] LDA
|
|
> \verbatim
|
|
> LDA is INTEGER
|
|
> On entry, LDA specifies the first dimension of A as declared
|
|
> in the calling (sub) program. When TRANS = 'N' or 'n'
|
|
> then LDA must be at least max( 1, n ), otherwise LDA must
|
|
> be at least max( 1, k ).
|
|
> \endverbatim
|
|
>
|
|
> \param[in] B
|
|
> \verbatim
|
|
> B is DOUBLE PRECISION array, dimension ( LDB, kb ), where kb is
|
|
> k when TRANS = 'N' or 'n', and is n otherwise.
|
|
> Before entry with TRANS = 'N' or 'n', the leading n by k
|
|
> part of the array B must contain the matrix B, otherwise
|
|
> the leading k by n part of the array B must contain the
|
|
> matrix B.
|
|
> \endverbatim
|
|
>
|
|
> \param[in] LDB
|
|
> \verbatim
|
|
> LDB is INTEGER
|
|
> On entry, LDB specifies the first dimension of B as declared
|
|
> in the calling (sub) program. When TRANS = 'N' or 'n'
|
|
> then LDB must be at least max( 1, n ), otherwise LDB must
|
|
> be at least max( 1, k ).
|
|
> \endverbatim
|
|
>
|
|
> \param[in] BETA
|
|
> \verbatim
|
|
> BETA is DOUBLE PRECISION.
|
|
> On entry, BETA specifies the scalar beta.
|
|
> \endverbatim
|
|
>
|
|
> \param[in,out] C
|
|
> \verbatim
|
|
> C is DOUBLE PRECISION array, dimension ( LDC, N )
|
|
> Before entry with UPLO = 'U' or 'u', the leading n by n
|
|
> upper triangular part of the array C must contain the upper
|
|
> triangular part of the symmetric matrix and the strictly
|
|
> lower triangular part of C is not referenced. On exit, the
|
|
> upper triangular part of the array C is overwritten by the
|
|
> upper triangular part of the updated matrix.
|
|
> Before entry with UPLO = 'L' or 'l', the leading n by n
|
|
> lower triangular part of the array C must contain the lower
|
|
> triangular part of the symmetric matrix and the strictly
|
|
> upper triangular part of C is not referenced. On exit, the
|
|
> lower triangular part of the array C is overwritten by the
|
|
> lower triangular part of the updated matrix.
|
|
> \endverbatim
|
|
>
|
|
> \param[in] LDC
|
|
> \verbatim
|
|
> LDC is INTEGER
|
|
> On entry, LDC specifies the first dimension of C as declared
|
|
> in the calling (sub) program. LDC must be at least
|
|
> max( 1, n ).
|
|
> \endverbatim
|
|
|
|
Authors:
|
|
========
|
|
|
|
> \author Univ. of Tennessee
|
|
> \author Univ. of California Berkeley
|
|
> \author Univ. of Colorado Denver
|
|
> \author NAG Ltd.
|
|
|
|
> \ingroup her2k
|
|
|
|
> \par Further Details:
|
|
=====================
|
|
>
|
|
> \verbatim
|
|
>
|
|
> Level 3 Blas routine.
|
|
>
|
|
>
|
|
> -- Written on 8-February-1989.
|
|
> Jack Dongarra, Argonne National Laboratory.
|
|
> Iain Duff, AERE Harwell.
|
|
> Jeremy Du Croz, Numerical Algorithms Group Ltd.
|
|
> Sven Hammarling, Numerical Algorithms Group Ltd.
|
|
> \endverbatim
|
|
>
|
|
=====================================================================
|
|
Subroutine */ int igraphdsyr2k_(char *uplo, char *trans, integer *n, integer *k,
|
|
doublereal *alpha, doublereal *a, integer *lda, doublereal *b,
|
|
integer *ldb, doublereal *beta, doublereal *c__, integer *ldc)
|
|
{
|
|
/* System generated locals */
|
|
integer a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset, i__1, i__2,
|
|
i__3;
|
|
|
|
/* Local variables */
|
|
integer i__, j, l, info;
|
|
doublereal temp1, temp2;
|
|
extern logical igraphlsame_(char *, char *);
|
|
integer nrowa;
|
|
logical upper;
|
|
extern /* Subroutine */ int igraphxerbla_(char *, integer *, ftnlen);
|
|
|
|
|
|
/* -- Reference BLAS level3 routine --
|
|
-- Reference BLAS is a software package provided by Univ. of Tennessee, --
|
|
-- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
|
|
|
|
|
|
=====================================================================
|
|
|
|
|
|
Test the input parameters.
|
|
|
|
Parameter adjustments */
|
|
a_dim1 = *lda;
|
|
a_offset = 1 + a_dim1;
|
|
a -= a_offset;
|
|
b_dim1 = *ldb;
|
|
b_offset = 1 + b_dim1;
|
|
b -= b_offset;
|
|
c_dim1 = *ldc;
|
|
c_offset = 1 + c_dim1;
|
|
c__ -= c_offset;
|
|
|
|
/* Function Body */
|
|
if (igraphlsame_(trans, "N")) {
|
|
nrowa = *n;
|
|
} else {
|
|
nrowa = *k;
|
|
}
|
|
upper = igraphlsame_(uplo, "U");
|
|
|
|
info = 0;
|
|
if (! upper && ! igraphlsame_(uplo, "L")) {
|
|
info = 1;
|
|
} else if (! igraphlsame_(trans, "N") && ! igraphlsame_(trans,
|
|
"T") && ! igraphlsame_(trans, "C")) {
|
|
info = 2;
|
|
} else if (*n < 0) {
|
|
info = 3;
|
|
} else if (*k < 0) {
|
|
info = 4;
|
|
} else if (*lda < max(1,nrowa)) {
|
|
info = 7;
|
|
} else if (*ldb < max(1,nrowa)) {
|
|
info = 9;
|
|
} else if (*ldc < max(1,*n)) {
|
|
info = 12;
|
|
}
|
|
if (info != 0) {
|
|
igraphxerbla_("DSYR2K", &info, (ftnlen)6);
|
|
return 0;
|
|
}
|
|
|
|
/* Quick return if possible. */
|
|
|
|
if (*n == 0 || (*alpha == 0. || *k == 0) && *beta == 1.) {
|
|
return 0;
|
|
}
|
|
|
|
/* And when alpha.eq.zero. */
|
|
|
|
if (*alpha == 0.) {
|
|
if (upper) {
|
|
if (*beta == 0.) {
|
|
i__1 = *n;
|
|
for (j = 1; j <= i__1; ++j) {
|
|
i__2 = j;
|
|
for (i__ = 1; i__ <= i__2; ++i__) {
|
|
c__[i__ + j * c_dim1] = 0.;
|
|
/* L10: */
|
|
}
|
|
/* L20: */
|
|
}
|
|
} else {
|
|
i__1 = *n;
|
|
for (j = 1; j <= i__1; ++j) {
|
|
i__2 = j;
|
|
for (i__ = 1; i__ <= i__2; ++i__) {
|
|
c__[i__ + j * c_dim1] = *beta * c__[i__ + j * c_dim1];
|
|
/* L30: */
|
|
}
|
|
/* L40: */
|
|
}
|
|
}
|
|
} else {
|
|
if (*beta == 0.) {
|
|
i__1 = *n;
|
|
for (j = 1; j <= i__1; ++j) {
|
|
i__2 = *n;
|
|
for (i__ = j; i__ <= i__2; ++i__) {
|
|
c__[i__ + j * c_dim1] = 0.;
|
|
/* L50: */
|
|
}
|
|
/* L60: */
|
|
}
|
|
} else {
|
|
i__1 = *n;
|
|
for (j = 1; j <= i__1; ++j) {
|
|
i__2 = *n;
|
|
for (i__ = j; i__ <= i__2; ++i__) {
|
|
c__[i__ + j * c_dim1] = *beta * c__[i__ + j * c_dim1];
|
|
/* L70: */
|
|
}
|
|
/* L80: */
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Start the operations. */
|
|
|
|
if (igraphlsame_(trans, "N")) {
|
|
|
|
/* Form C := alpha*A*B**T + alpha*B*A**T + C. */
|
|
|
|
if (upper) {
|
|
i__1 = *n;
|
|
for (j = 1; j <= i__1; ++j) {
|
|
if (*beta == 0.) {
|
|
i__2 = j;
|
|
for (i__ = 1; i__ <= i__2; ++i__) {
|
|
c__[i__ + j * c_dim1] = 0.;
|
|
/* L90: */
|
|
}
|
|
} else if (*beta != 1.) {
|
|
i__2 = j;
|
|
for (i__ = 1; i__ <= i__2; ++i__) {
|
|
c__[i__ + j * c_dim1] = *beta * c__[i__ + j * c_dim1];
|
|
/* L100: */
|
|
}
|
|
}
|
|
i__2 = *k;
|
|
for (l = 1; l <= i__2; ++l) {
|
|
if (a[j + l * a_dim1] != 0. || b[j + l * b_dim1] != 0.) {
|
|
temp1 = *alpha * b[j + l * b_dim1];
|
|
temp2 = *alpha * a[j + l * a_dim1];
|
|
i__3 = j;
|
|
for (i__ = 1; i__ <= i__3; ++i__) {
|
|
c__[i__ + j * c_dim1] = c__[i__ + j * c_dim1] + a[
|
|
i__ + l * a_dim1] * temp1 + b[i__ + l *
|
|
b_dim1] * temp2;
|
|
/* L110: */
|
|
}
|
|
}
|
|
/* L120: */
|
|
}
|
|
/* L130: */
|
|
}
|
|
} else {
|
|
i__1 = *n;
|
|
for (j = 1; j <= i__1; ++j) {
|
|
if (*beta == 0.) {
|
|
i__2 = *n;
|
|
for (i__ = j; i__ <= i__2; ++i__) {
|
|
c__[i__ + j * c_dim1] = 0.;
|
|
/* L140: */
|
|
}
|
|
} else if (*beta != 1.) {
|
|
i__2 = *n;
|
|
for (i__ = j; i__ <= i__2; ++i__) {
|
|
c__[i__ + j * c_dim1] = *beta * c__[i__ + j * c_dim1];
|
|
/* L150: */
|
|
}
|
|
}
|
|
i__2 = *k;
|
|
for (l = 1; l <= i__2; ++l) {
|
|
if (a[j + l * a_dim1] != 0. || b[j + l * b_dim1] != 0.) {
|
|
temp1 = *alpha * b[j + l * b_dim1];
|
|
temp2 = *alpha * a[j + l * a_dim1];
|
|
i__3 = *n;
|
|
for (i__ = j; i__ <= i__3; ++i__) {
|
|
c__[i__ + j * c_dim1] = c__[i__ + j * c_dim1] + a[
|
|
i__ + l * a_dim1] * temp1 + b[i__ + l *
|
|
b_dim1] * temp2;
|
|
/* L160: */
|
|
}
|
|
}
|
|
/* L170: */
|
|
}
|
|
/* L180: */
|
|
}
|
|
}
|
|
} else {
|
|
|
|
/* Form C := alpha*A**T*B + alpha*B**T*A + C. */
|
|
|
|
if (upper) {
|
|
i__1 = *n;
|
|
for (j = 1; j <= i__1; ++j) {
|
|
i__2 = j;
|
|
for (i__ = 1; i__ <= i__2; ++i__) {
|
|
temp1 = 0.;
|
|
temp2 = 0.;
|
|
i__3 = *k;
|
|
for (l = 1; l <= i__3; ++l) {
|
|
temp1 += a[l + i__ * a_dim1] * b[l + j * b_dim1];
|
|
temp2 += b[l + i__ * b_dim1] * a[l + j * a_dim1];
|
|
/* L190: */
|
|
}
|
|
if (*beta == 0.) {
|
|
c__[i__ + j * c_dim1] = *alpha * temp1 + *alpha *
|
|
temp2;
|
|
} else {
|
|
c__[i__ + j * c_dim1] = *beta * c__[i__ + j * c_dim1]
|
|
+ *alpha * temp1 + *alpha * temp2;
|
|
}
|
|
/* L200: */
|
|
}
|
|
/* L210: */
|
|
}
|
|
} else {
|
|
i__1 = *n;
|
|
for (j = 1; j <= i__1; ++j) {
|
|
i__2 = *n;
|
|
for (i__ = j; i__ <= i__2; ++i__) {
|
|
temp1 = 0.;
|
|
temp2 = 0.;
|
|
i__3 = *k;
|
|
for (l = 1; l <= i__3; ++l) {
|
|
temp1 += a[l + i__ * a_dim1] * b[l + j * b_dim1];
|
|
temp2 += b[l + i__ * b_dim1] * a[l + j * a_dim1];
|
|
/* L220: */
|
|
}
|
|
if (*beta == 0.) {
|
|
c__[i__ + j * c_dim1] = *alpha * temp1 + *alpha *
|
|
temp2;
|
|
} else {
|
|
c__[i__ + j * c_dim1] = *beta * c__[i__ + j * c_dim1]
|
|
+ *alpha * temp1 + *alpha * temp2;
|
|
}
|
|
/* L230: */
|
|
}
|
|
/* L240: */
|
|
}
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
|
|
/* End of DSYR2K */
|
|
|
|
} /* igraphdsyr2k_ */
|
|
|