CXML
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
m integer*4
On entry, the number of rows of the matrix A; m >= 0.
On exit, m is unchanged.
n integer*4
On entry, the number of columns of the matrix A; n >=
0.
On exit, n is unchanged.
alpha real*4 | real*8 | complex*8 | complex*16
On entry, the scalar alpha*.
On exit, alpha is unchanged.
x real*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.
incx integer*4
On entry, the increment for the elements of X; incx
must not equal zero.
On exit, incx is unchanged.
y real*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.
incy integer*4
On entry, the increment for the elements of Y; incy
must not equal zero.
On exit, incy is unchanged.
a real*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.
lda integer*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 () 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 () and starting at
location A(1,1), is updated.
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