Name

sger, dger, cgerc, zgerc, cgeru, zgeru − Rank-one update of a general matrix

FORMAT

{S,D}GER (m, n, alpha, x, incx, y, incy, a, lda) {C,Z}GER{C,U} (m, n, alpha, x, incx, y, incy, a, lda)

Arguments

minteger∗4
On entry, the number of rows of the matrix A; m >= 0.
On exit, m is unchanged. 

ninteger∗4
On entry, the number of columns of the matrix A; n >= 0.
On exit, n is unchanged. 

alphareal∗4 | real∗8 | complex∗8 | complex∗16
On entry, the scalar alpha∗.
On exit, alpha is unchanged. 

xreal∗4 | real∗8 | complex∗8 | complex∗16
On entry, a one-dimensional array X of length at least (1+(m-1)∗|incx|).  Array X contains the vector x.
On exit, x is unchanged. 

incxinteger∗4
On entry, the increment for the elements of X; incx must not equal zero.
On exit, incx is unchanged. 

yreal∗4 | real∗8 | complex∗8 | complex∗16
On entry, a one-dimensional array of length at least (1+(n-1)∗|incy|).  The incremented array Y must contain the vector y.
On exit, y is unchanged. 

incyinteger∗4
On entry, the increment for the elements of Y; incy must not equal zero.
On exit, incy is unchanged. 

areal∗4 | real∗8 | complex∗8 | complex∗16
On entry, a two-dimensional array with dimensions lda by n. The leading m by n part of the array contains the elements of the matrix A.
On exit, a is overwritten by the updated matrix. 

ldainteger∗4
On entry, the first dimension of A; lda >= MAX(1,m).
On exit, lda is unchanged. 

Description

SGER and DGER perform a rank-one update of a real general matrix: A  = alpha∗x∗transp(y) + A

CGERU and ZGERU perform a rank-one update of an unconjugated complex general matrix: A  = alpha∗x∗transp(y) + A

CGERC and ZGERC perform a rank-one update of a conjugated complex general matrix: A  = alpha∗x∗conjug_transp(y) + A

alphais a scalar, x is an m-element vector, y is an n-element vector, and A is an m by n matrix. 

EXAMPLES

REAL∗4 A(10,10), X(10), Y(5), alpha
INCX = 1
INCY = 1
LDA = 10
M = 3
N = 4
alpha = 2.3
CALL SGER(M,N,alpha,X,INCX,Y,INCY,A,LDA)

This FORTRAN code computes the rank-1 update A  =  alpha∗x∗transp(y)
 + A.  Only the upper left submatrix of A, of dimension (3,4) and starting at location A(1,1), is updated.

COMPLEX∗8 A(10,10), X(10), Y(5), alpha
INCX = 1
INCY = 1
LDA = 10
M = 3
N = 4
alpha = (2.3, 1.2)
CALL CGERC(M,N,alpha,X,INCX,Y,INCY,A,LDA)

This FORTRAN code computes the rank-1 update A  =  alpha∗x∗conjug_transp(y) + A. Only the upper left submatrix of A, of dimension (3,4) and starting at location A(1,1), is updated.