mirror of
https://github.com/opencv/opencv.git
synced 2024-11-29 05:29:54 +08:00
166 lines
4.3 KiB
C
166 lines
4.3 KiB
C
#include "clapack.h"
|
|
|
|
|
|
/* Subroutine */ int dger_(integer *_m, integer *_n, doublereal *_alpha,
|
|
doublereal *x, integer *_incx, doublereal *y, integer *_incy,
|
|
doublereal *a, integer *_lda)
|
|
{
|
|
|
|
/* .. Scalar Arguments .. */
|
|
/* .. */
|
|
/* .. Array Arguments .. */
|
|
/* .. */
|
|
|
|
/* Purpose */
|
|
/* ======= */
|
|
|
|
/* DGER performs the rank 1 operation */
|
|
|
|
/* A := alpha*x*y' + 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. */
|
|
|
|
/* Arguments */
|
|
/* ========== */
|
|
|
|
/* M - INTEGER. */
|
|
/* On entry, M specifies the number of rows of the matrix A. */
|
|
/* M must be at least zero. */
|
|
/* Unchanged on exit. */
|
|
|
|
/* N - INTEGER. */
|
|
/* On entry, N specifies the number of columns of the matrix A. */
|
|
/* N must be at least zero. */
|
|
/* Unchanged on exit. */
|
|
|
|
/* ALPHA - DOUBLE PRECISION. */
|
|
/* On entry, ALPHA specifies the scalar alpha. */
|
|
/* Unchanged on exit. */
|
|
|
|
/* X - DOUBLE PRECISION array of dimension at least */
|
|
/* ( 1 + ( m - 1 )*abs( INCX ) ). */
|
|
/* Before entry, the incremented array X must contain the m */
|
|
/* element vector x. */
|
|
/* Unchanged on exit. */
|
|
|
|
/* INCX - INTEGER. */
|
|
/* On entry, INCX specifies the increment for the elements of */
|
|
/* X. INCX must not be zero. */
|
|
/* Unchanged on exit. */
|
|
|
|
/* Y - DOUBLE PRECISION array of dimension at least */
|
|
/* ( 1 + ( n - 1 )*abs( INCY ) ). */
|
|
/* Before entry, the incremented array Y must contain the n */
|
|
/* element vector y. */
|
|
/* Unchanged on exit. */
|
|
|
|
/* INCY - INTEGER. */
|
|
/* On entry, INCY specifies the increment for the elements of */
|
|
/* Y. INCY must not be zero. */
|
|
/* Unchanged on exit. */
|
|
|
|
/* A - DOUBLE PRECISION array of 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. */
|
|
|
|
/* LDA - 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 ). */
|
|
/* Unchanged on exit. */
|
|
|
|
|
|
/* 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. */
|
|
|
|
|
|
/* .. Parameters .. */
|
|
/* .. */
|
|
/* .. Local Scalars .. */
|
|
/* .. */
|
|
/* .. External Subroutines .. */
|
|
/* .. */
|
|
/* .. Intrinsic Functions .. */
|
|
/* .. */
|
|
|
|
/* Test the input parameters. */
|
|
|
|
/* Function Body */
|
|
integer i, j, m = *_m, n = *_n, incx = *_incx, incy = *_incy, lda = *_lda;
|
|
doublereal alpha = *_alpha;
|
|
integer 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)
|
|
{
|
|
xerbla_("DGER ", &info);
|
|
return 0;
|
|
}
|
|
|
|
if (incx < 0)
|
|
x -= (m-1)*incx;
|
|
if (incy < 0)
|
|
y -= (n-1)*incy;
|
|
|
|
/* Start the operations. In this version the elements of A are */
|
|
/* accessed sequentially with one pass through A. */
|
|
|
|
if( alpha == 0 )
|
|
;
|
|
else if( incx == 1 )
|
|
{
|
|
for( j = 0; j < n; j++, a += lda )
|
|
{
|
|
doublereal s = y[j*incy];
|
|
if( s == 0 )
|
|
continue;
|
|
s *= alpha;
|
|
|
|
for( i = 0; i <= m - 2; i += 2 )
|
|
{
|
|
doublereal t0 = a[i] + x[i]*s;
|
|
doublereal t1 = a[i+1] + x[i+1]*s;
|
|
a[i] = t0; a[i+1] = t1;
|
|
}
|
|
|
|
for( ; i < m; i++ )
|
|
a[i] += x[i]*s;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
for( j = 0; j < n; j++, a += lda )
|
|
{
|
|
doublereal s = y[j*incy];
|
|
if( s == 0 )
|
|
continue;
|
|
s *= alpha;
|
|
|
|
for( i = 0; i < m; i++ )
|
|
a[i] += x[i*incx]*s;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
|
|
/* End of DGER . */
|
|
|
|
} /* dger_ */
|