Developer Reference

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

p?getrs

Solves a system of distributed linear equations with a general square matrix, using the
LU
factorization computed by
p?getrf
.

Syntax

call psgetrs
(
trans
,
n
,
nrhs
,
a
,
ia
,
ja
,
desca
,
ipiv
,
b
,
ib
,
jb
,
descb
,
info
)
call pdgetrs
(
trans
,
n
,
nrhs
,
a
,
ia
,
ja
,
desca
,
ipiv
,
b
,
ib
,
jb
,
descb
,
info
)
call pcgetrs
(
trans
,
n
,
nrhs
,
a
,
ia
,
ja
,
desca
,
ipiv
,
b
,
ib
,
jb
,
descb
,
info
)
call pzgetrs
(
trans
,
n
,
nrhs
,
a
,
ia
,
ja
,
desca
,
ipiv
,
b
,
ib
,
jb
,
descb
,
info
)
Include Files
Description
The
p?getrs
routine
solves a system of distributed linear equations with a general
n
-by-
n
distributed matrix sub(
A
) =
A
(
ia
:
ia
+
n
-1,
ja
:
ja
+
n
-1) using the
LU
factorization computed by
p?getrf
.
The system has one of the following forms specified by
trans
:
sub(
A
)*
X
= sub(
B
) (no transpose),
sub(
A
)
T
*
X
= sub(
B
) (transpose),
sub(
A
)
H
*
X
= sub(
B
) (conjugate transpose),
where sub(
B
) =
B
(
ib
:
ib
+
n
-1,
jb
:
jb
+
nrhs
-1).
Before calling this
routine
,you must call
p?getrf
to compute the
LU
factorization of sub(
A
).
Input Parameters
trans
(global)
CHARACTER*1
.
Must be
'N'
or
'T'
or
'C'
.
Indicates the form of the equations:
If
trans
=
'N'
, then sub(
A
)*
X
= sub(
B
) is solved for
X
.
If
trans
=
'T'
, then sub(
A
)
T