Developer Reference for Intel® oneAPI Math Kernel Library - C

Developer Reference

Contents

?lapmt

Performs a forward or backward permutation of the columns of a matrix.

Syntax

lapack_int
LAPACKE_slapmt
(
int
matrix_layout
,
lapack_logical
forwrd
,
lapack_int
m
,
lapack_int
n
,
float
*
x
,
lapack_int
ldx
,
lapack_int
*
k
);
lapack_int
LAPACKE_dlapmt
(
int
matrix_layout
,
lapack_logical
forwrd
,
lapack_int
m
,
lapack_int
n
,
double
*
x
,
lapack_int
ldx
,
lapack_int
*
k
);
lapack_int
LAPACKE_clapmt
(
int
matrix_layout
,
lapack_logical
forwrd
,
lapack_int
m
,
lapack_int
n
,
lapack_complex_float
*
x
,
lapack_int
ldx
,
lapack_int
*
k
);
lapack_int
LAPACKE_zlapmt
(
int
matrix_layout
,
lapack_logical
forwrd
,
lapack_int
m
,
lapack_int
n
,
lapack_complex_double
*
x
,
lapack_int
ldx
,
lapack_int
*
k
);
Include Files
  • mkl.h
Description
The routine
?lapmt
 rearranges the columns of the
m
-by-
n
 matrix
X
 as specified by the permutation
k
[
i
 - 1]
for
i
 = 1,...,
n
.
If
forwrd
≠
 0
, forward permutation:
X
(*,
k
(
j
))
 is moved to
X
(*,
j
)
 for
j
=1,2,...,
n
.
If
forwrd
 =
0
, backward permutation:
X
(*,
j
)
 is moved to
X
(*,
k
(
j
))
 for
j
 = 1,2,...,
n
.
Input Parameters
matrix_layout
Specifies whether matrix storage layout is row major (
LAPACK_ROW_MAJOR
) or column major (
LAPACK_COL_MAJOR
).
forwrd
If
forwrd
≠
 0
, forward permutation
If
forwrd
 =
0
, backward permutation
m
The number of rows of the matrix
X
.
m
≥
 0
.
n
The number of columns of the matrix
X
.
n
≥
 0
.
x
Array, size
ldx
*
n
. On entry, the
m
-by-
n
 matrix
X
.
ldx
The leading dimension of the array
x
,
ldx
≥
 max(1,
m
).
k
Array, size (
n
). On entry,
k
 contains the permutation vector and is used as internal workspace.
Output Parameters
x
On exit,
x
 contains the permuted matrix
X
.
k
On exit,
k
 is reset to its original value.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.