Developer Reference

  • 0.10
  • 10/21/2020
  • Public Content
Contents

?lansy

Returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a real/complex symmetric matrix.

Syntax

float
LAPACKE_slansy
(
int
matrix_layout
,
char
norm
,
char
uplo
,
lapack_int
n
,
const
float
*
a
,
lapack_int
lda
);
double
LAPACKE_dlansy
(
int
matrix_layout
,
char
norm
,
char
uplo
,
lapack_int
n
,
const
double
*
a
,
lapack_int
lda
);
float
LAPACKE_clansy
(
int
matrix_layout
,
char
norm
,
char
uplo
,
lapack_int
n
,
const
lapack_complex_float
*
a
,
lapack_int
lda
);
double
LAPACKE_zlansy
(
int
matrix_layout
,
char
norm
,
char
uplo
,
lapack_int
n
,
const
lapack_complex_double
*
a
,
lapack_int
lda
);
Include Files
  • mkl.h
Description
The function
?lansy
returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a real/complex symmetric matrix
A
.
Input Parameters
A
<datatype>
placeholder, if present, is used for the C interface data types in the C interface section above. See C Interface Conventions for the C interface principal conventions and type definitions.
norm
Specifies the value to be returned by the routine:
=
'M'
or
'm':
val
=
max
(
abs
(
A
ij
))
, largest absolute value of the matrix
A
.
=
'1'
or
'O'
or
'o':
val
=
norm1
(
A
)
, 1-norm of the matrix
A
(maximum column sum),
=
'I'
or
'i':
val
=
normI
(
A
)
, infinity norm of the matrix
A
(maximum row sum),
=
'F'
,
'f'
,
'E'
or
'e':
val
=
normF
(
A
)
, Frobenius norm of the matrix
A
(square root of sum of squares).
uplo
Specifies whether the upper or lower triangular part of the symmetric matrix
A
is to be referenced.
=
'U'
: Upper triangular part of
A
is referenced.
=
'L'
: Lower triangular part of
A
is referenced
n
The order of the matrix
A
.
n
0
. When
n
= 0
,
?lansy
is set to zero.
a
Array, size
at least max(1,
lda
*
n
)
. The symmetric matrix
A
.
If
uplo
=
'U'
, the leading
n
-by-
n
upper triangular part of
a
contains the upper triangular part of the matrix
A
, and the strictly lower triangular part of
a
is not referenced.
If
uplo
=
'L'
, the leading
n
-by-
n
lower triangular part of
a
contains the lower triangular part of the matrix
A
, and the strictly upper triangular part of
a
is not referenced.
lda
The leading dimension of the array
a
.
lda
max(
n
,1).

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