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# zgeru

## man page of zgeru

### zgeru: perform the rank 1 operation A := alpha*x*y' + A,

##### NAME
ZGERU - perform the rank 1 operation A := alpha*x*y' + A,
###### SYNOPSIS
SUBROUTINE ZGERU ( M, N, ALPHA, X, INCX, Y, INCY, A, LDA ) COMPLEX*16 ALPHA INTEGER INCX, INCY, LDA, M, N COMPLEX*16 A( LDA, * ), X( * ), Y( * )

PURPOSE

ZGERU performs the rank 1 operation 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.

## PARAMETERS

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 - COMPLEX*16 . On entry, ALPHA specifies the scalar alpha. Unchanged on exit. X - COMPLEX*16 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 - COMPLEX*16 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 - COMPLEX*16 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. ZGERU(3)