Developer Reference

  • 2020.2
  • 07/15/2020
  • Public Content
Contents

mkl_?getrfnp

Computes the LU factorization of a general m-by-n matrix without pivoting.

Syntax

call mkl_sgetrfnp
(
m
,
n
,
a
,
lda
,
info
)
call mkl_dgetrfnp
(
m
,
n
,
a
,
lda
,
info
)
call mkl_cgetrfnp
(
m
,
n
,
a
,
lda
,
info
)
call mkl_zgetrfnp
(
m
,
n
,
a
,
lda
,
info
)
Include Files
  • mkl.fi
Description
The routine computes the
LU
factorization of a general
m
-by-
n
matrix
A
as
A
=
L*U
,
where
L
is lower triangular with unit-diagonal elements (lower trapezoidal if
m
>
n
) and
U
is upper triangular (upper trapezoidal if
m
<
n
). The routine does not use pivoting.
Input Parameters
m
INTEGER
.
The number of rows in the matrix
A
(
m
0).
n
INTEGER
.
The number of columns in
A
;
n
0.
a
REAL
for
mkl_sgetrfnp
DOUBLE PRECISION
for
mkl_dgetrfnp
COMPLEX
for
mkl_cgetrfnp
DOUBLE COMPLEX
for
mkl_zgetrfnp
.
Array, size
lda
by
*
. Contains the matrix
A
.
The second dimension of
a
must be at least
max(1,
n
)
.
lda
INTEGER
.
The leading dimension of array
a
.
Output Parameters
a
Overwritten by
L
and
U
. The unit diagonal elements of
L
are not stored.
info
INTEGER
.
If
info
=0
, the execution is successful.
If
info
=
-i
, the
i
-th parameter had an illegal value.
If
info
=
i
,
u
i
i
is 0. The factorization has been completed, but
U
is exactly singular. Division by 0 will occur if you use the factor
U
for solving a system of linear equations.
Application Notes
The approximate number of floating-point operations for real flavors is
(2/3)
n
3
If
m
=
n
,
(1/3)
n
2
(3
m
-
n
)
If
m
>
n
,
(1/3)
m
2
(3