Developer Reference

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

mkl_?getrfnpi

Performs LU factorization (complete or incomplete) of a general matrix without pivoting.

Syntax

call mkl_sgetrfnpi
(
m
,
 n
,
 nfact
,
 a
,
 lda
,
 info
)
call mkl_dgetrfnpi
(
m
,
 n
,
 nfact
,
 a
,
 lda
,
 info 
)
call mkl_cgetrfnpi
(
m
,
 n
,
 nfact
,
 a
,
 lda
,
 info 
)
call mkl_zgetrfnpi
(
m
,
 n
,
nfact
,
 a
,
 lda
,
 info 
)
call mkl_getrfnpi
(
 a 
[
,
nfact
] [
,
info
)
Include Files
  • mkl.fi, lapack.f90
Description
The routine computes the LU factorization of a general
m
-by-
n
matrix
A
without using pivoting. It supports incomplete factorization. The factorization has the form:
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
).
Incomplete factorization has the form:
where
L
is lower trapezoidal with unit diagonal elements,
U
is upper trapezoidal, and is the unfactored part of matrix
A
. See the application notes section for further details.
Use
?getrf
if it is possible that the matrix is not diagonal dominant.
Input Parameters
The data types are given for the Fortran interface.
m
INTEGER.
The number of rows in matrix
A
;
m
0.
n
INTEGER.
The number of columns in matrix
A
;
n
0.
nfact
INTEGER.
The number of rows and columns to factor; 0
nfact
min(
m
,
n
). Note that if
nfact
< min(
m
,
n
), incomplete factorization is performed.
a
REAL
for
mkl_sgetrfnpi
DOUBLE PRECISION
for
mkl_dgetrfnpi
COMPLEX
for
mkl_cgetrfnpi
DOUBLE COMPLEX
for
mkl_zgetrfnpi
Array of size
(
lda
,*)
. Contains the matrix
A
.
The second dimension of
a
must be at least max(1,
n
).
lda
INTEGER.
The leading dimension of array
a
.
lda
max(1,
m
).
Output Parameters
a
Overwritten by
L
and
U
. The unit diagonal elements of