Developer Reference

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

?getrf

Computes the LU factorization of a general m-by-n matrix.

Syntax

call sgetrf
(
m
,
n
,
a
,
lda
,
ipiv
,
info
)
call dgetrf
(
m
,
n
,
a
,
lda
,
ipiv
,
info
)
call cgetrf
(
m
,
n
,
a
,
lda
,
ipiv
,
info
)
call zgetrf
(
m
,
n
,
a
,
lda
,
ipiv
,
info
)
call getrf
(
a
[
,
ipiv
]
[
,
info
]
)
Include Files
  • mkl.fi
    ,
    lapack.f90
Description
The routine computes the
LU
factorization of a general
m
-by-
n
matrix
A
as
A
=
P*L*U
,
where
P
is a permutation matrix,
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 uses partial pivoting, with row interchanges.
This routine supports the Progress Routine feature. See Progress Function for details.
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
sgetrf
DOUBLE PRECISION
for
dgetrf
COMPLEX
for
cgetrf
DOUBLE COMPLEX
for
zgetrf
.
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.
ipiv
INTEGER
.
Array, size at least
max(1,min(
m
,
n
))
. Contains the pivot indices; for
1
i
min(
m
,
n
)
, row
i
was interchanged with row
ipiv
(
i
)
.
info
INTEGER
.
If