Developer Reference for Intel® oneAPI Math Kernel Library - C

Developer Reference

  • 0.9
  • 09/09/2020
  • Public Content
Contents

?syr

Performs the symmetric rank-1 update of a complex symmetric matrix.

Syntax

lapack_int
LAPACKE_csyr
(
int
matrix_layout
,
char
uplo
,
lapack_int
n
,
lapack_complex_float
alpha
,
const
lapack_complex_float
*
x
,
lapack_int
incx
,
lapack_complex_float
*
a
,
lapack_int
lda
);
lapack_int
LAPACKE_zsyr
(
int
matrix_layout
,
char
uplo
,
lapack_int
n
,
lapack_complex_double
alpha
,
const
lapack_complex_double
*
x
,
lapack_int
incx
,
lapack_complex_double
*
a
,
lapack_int
lda
);
Include Files
  • mkl.h
Description
The routine performs the symmetric rank 1 operation defined as
a
 :=
alpha
*
x
*
x
H
 +
a
,
where:
  • alpha
     is a complex scalar.
  • x
     is an
    n
    -element complex vector.
  • a
     is an
    n
    -by-
    n
     complex symmetric matrix.
These routines have their real equivalents in BLAS (see
?syr
 in Chapter 
"BLAS and Sparse BLAS Routines"
).
Input Parameters
matrix_layout
Specifies whether matrix storage layout is row major (
LAPACK_ROW_MAJOR
) or column major (
LAPACK_COL_MAJOR
).
uplo
Specifies whether the upper or lower triangular part of the array
a
 is used:
If
uplo
 =
'U'
 or
'u'
, then the upper triangular part of the array
a
 is used.
If
uplo
 =
'L'
 or
'l'
, then the lower triangular part of the array
a
 is used.
n
Specifies the order of the matrix
a
. The value of
n
 must be at least zero.
alpha
Specifies the scalar
alpha
.
x
Array, size at least
(1 + (
n
 - 1)*abs(
incx
))
. Before entry, the incremented array
x
 must contain the
n
-element vector
x
.
incx
Specifies the increment for the elements of
x
. The value of
incx
 must not be zero.
a
Array, size
max(1,
lda
*
n
)
. Before entry with
uplo
 =
'U'
 or
'u'
, the leading
n
-by-
n
 upper triangular part of the array
a
 must contain the upper triangular part of the symmetric matrix and the strictly lower triangular part of
a
 is not referenced.
Before entry with
uplo
 =
'L'
 or
'l'
, the leading
n
-by-
n
 lower triangular part of the array
a
 must contain the lower triangular part of the symmetric matrix and the strictly upper triangular part of
a
 is not referenced.
lda
Specifies the leading dimension of
a
 as declared in the calling (sub)program. The value of
lda
 must be at least
max
(1,
n
)
.
Output Parameters
a
With
uplo
 =
'U'
 or
'u'
, the upper triangular part of the array
a
 is overwritten by the upper triangular part of the updated matrix.
With
uplo
 =
'L'
 or
'l'
, the lower triangular part of the array
a
 is overwritten by the lower triangular part of the updated matrix.
Return Values
This function returns a value
info
.
If
info
 = 0
, the execution is successful.
If
info
 < 0
, the
i
-th parameter had an illegal value.
If
info
 = -1011
, memory allocation error occurred.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804