cblas_?syr
cblas_?syr
Performs
a rank-1 update of a symmetric matrix.Syntax
void
cblas_ssyr
(
const
CBLAS_LAYOUT
Layout
,
const
CBLAS_UPLO
uplo
,
const
MKL_INT
n
,
const
float
alpha
,
const
float
*x
,
const
MKL_INT
incx
,
float
*a
,
const
MKL_INT
lda
);
void
cblas_dsyr
(
const
CBLAS_LAYOUT
Layout
,
const
CBLAS_UPLO
uplo
,
const
MKL_INT
n
,
const
double
alpha
,
const
double
*x
,
const
MKL_INT
incx
,
double
*a
,
const
MKL_INT
lda
);
Include Files
- mkl.h
Description
The
?syr
routines perform a matrix-vector operation defined asA
:= alpha
*x
*x
' + A
where:
alpha
is a real scalar,x
is an n
-element vector,A
is an n
-by-n
symmetric matrix.Input Parameters
- Layout
- Specifies whether two-dimensional array storage is row-major (CblasRowMajor) or column-major (CblasColMajor).
- uplo
- Specifies whether the upper or lower triangular part of the arrayais used.If, then the upper triangular part of the arrayuplo=CblasUpperais used.If, then the low triangular part of the arrayuplo=CblasLowerais used.
- n
- Specifies the order of the matrixA. The value ofnmust be at least zero.
- alpha
- Specifies the scalaralpha.
- x
- Array, size at least(1 + (. Before entry, the incremented arrayn-1)*abs(incx))xmust contain then-element vectorx.
- incx
- Specifies the increment for the elements ofx.The value ofincxmust not be zero.
- a
- Array, size.lda*nBefore entry with, the leadinguplo=CblasUppern-by-nupper triangular part of the arrayamust contain the upper triangular part of the symmetric matrixAand the strictly lower triangular part ofais not referenced.Before entry with, the leadinguplo=CblasLowern-by-nlower triangular part of the arrayamust contain the lower triangular part of the symmetric matrixAand the strictly upper triangular part ofais not referenced.
- lda
- Specifies the leading dimension ofaas declared in the calling (sub)program. The value ofldamust be at leastmax(1,.n)
Output Parameters
- a
- With, the upper triangular part of the arrayuplo=CblasUpperais overwritten by the upper triangular part of the updated matrix.With, the lower triangular part of the arrayuplo=CblasLowerais overwritten by the lower triangular part of the updated matrix.