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Abdelrahman Said a11edf0c53 Add graph references
2026-06-28 13:49:01 +01:00

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/* -- 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 DGER
=========== DOCUMENTATION ===========
Online html documentation available at
http://www.netlib.org/lapack/explore-html/
Definition:
===========
SUBROUTINE DGER(M,N,ALPHA,X,INCX,Y,INCY,A,LDA)
DOUBLE PRECISION ALPHA
INTEGER INCX,INCY,LDA,M,N
DOUBLE PRECISION A(LDA,*),X(*),Y(*)
> \par Purpose:
=============
>
> \verbatim
>
> DGER performs the rank 1 operation
>
> A := alpha*x*y**T + A,
>
> where alpha is a scalar, x is an m element vector, y is an n element
> vector and A is an m by n matrix.
> \endverbatim
Arguments:
==========
> \param[in] M
> \verbatim
> M is INTEGER
> On entry, M specifies the number of rows of the matrix A.
> M must be at least zero.
> \endverbatim
>
> \param[in] N
> \verbatim
> N is INTEGER
> On entry, N specifies the number of columns of the matrix A.
> N must be at least zero.
> \endverbatim
>
> \param[in] ALPHA
> \verbatim
> ALPHA is DOUBLE PRECISION.
> On entry, ALPHA specifies the scalar alpha.
> \endverbatim
>
> \param[in] X
> \verbatim
> X is DOUBLE PRECISION array, dimension at least
> ( 1 + ( m - 1 )*abs( INCX ) ).
> Before entry, the incremented array X must contain the m
> element vector x.
> \endverbatim
>
> \param[in] INCX
> \verbatim
> INCX is INTEGER
> On entry, INCX specifies the increment for the elements of
> X. INCX must not be zero.
> \endverbatim
>
> \param[in] Y
> \verbatim
> Y is DOUBLE PRECISION array, dimension at least
> ( 1 + ( n - 1 )*abs( INCY ) ).
> Before entry, the incremented array Y must contain the n
> element vector y.
> \endverbatim
>
> \param[in] INCY
> \verbatim
> INCY is INTEGER
> On entry, INCY specifies the increment for the elements of
> Y. INCY must not be zero.
> \endverbatim
>
> \param[in,out] A
> \verbatim
> A is DOUBLE PRECISION array, dimension ( LDA, N )
> Before entry, the leading m by n part of the array A must
> contain the matrix of coefficients. On exit, A is
> overwritten by the updated matrix.
> \endverbatim
>
> \param[in] LDA
> \verbatim
> LDA is INTEGER
> On entry, LDA specifies the first dimension of A as declared
> in the calling (sub) program. LDA must be at least
> max( 1, m ).
> \endverbatim
Authors:
========
> \author Univ. of Tennessee
> \author Univ. of California Berkeley
> \author Univ. of Colorado Denver
> \author NAG Ltd.
> \ingroup ger
> \par Further Details:
=====================
>
> \verbatim
>
> Level 2 Blas routine.
>
> -- Written on 22-October-1986.
> Jack Dongarra, Argonne National Lab.
> Jeremy Du Croz, Nag Central Office.
> Sven Hammarling, Nag Central Office.
> Richard Hanson, Sandia National Labs.
> \endverbatim
>
=====================================================================
Subroutine */ int igraphdger_(integer *m, integer *n, doublereal *alpha,
doublereal *x, integer *incx, doublereal *y, integer *incy,
doublereal *a, integer *lda)
{
/* System generated locals */
integer a_dim1, a_offset, i__1, i__2;
/* Local variables */
integer i__, j, ix, jy, kx, info;
doublereal temp;
extern /* Subroutine */ int igraphxerbla_(char *, integer *, ftnlen);
/* -- Reference BLAS level2 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 */
--x;
--y;
a_dim1 = *lda;
a_offset = 1 + a_dim1;
a -= a_offset;
/* Function Body */
info = 0;
if (*m < 0) {
info = 1;
} else if (*n < 0) {
info = 2;
} else if (*incx == 0) {
info = 5;
} else if (*incy == 0) {
info = 7;
} else if (*lda < max(1,*m)) {
info = 9;
}
if (info != 0) {
igraphxerbla_("DGER ", &info, (ftnlen)6);
return 0;
}
/* Quick return if possible. */
if (*m == 0 || *n == 0 || *alpha == 0.) {
return 0;
}
/* Start the operations. In this version the elements of A are
accessed sequentially with one pass through A. */
if (*incy > 0) {
jy = 1;
} else {
jy = 1 - (*n - 1) * *incy;
}
if (*incx == 1) {
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
if (y[jy] != 0.) {
temp = *alpha * y[jy];
i__2 = *m;
for (i__ = 1; i__ <= i__2; ++i__) {
a[i__ + j * a_dim1] += x[i__] * temp;
/* L10: */
}
}
jy += *incy;
/* L20: */
}
} else {
if (*incx > 0) {
kx = 1;
} else {
kx = 1 - (*m - 1) * *incx;
}
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
if (y[jy] != 0.) {
temp = *alpha * y[jy];
ix = kx;
i__2 = *m;
for (i__ = 1; i__ <= i__2; ++i__) {
a[i__ + j * a_dim1] += x[ix] * temp;
ix += *incx;
/* L30: */
}
}
jy += *incy;
/* L40: */
}
}
return 0;
/* End of DGER */
} /* igraphdger_ */