## Developer Reference

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

# p?trtri

Computes the inverse of a triangular distributed matrix.

## Syntax

Include Files
Description
The
p?trtri
routine
computes the inverse of a real or complex upper or lower triangular distributed matrix sub(
A
) =
A
(
ia
:
ia
+
n
-1,
ja
:
ja
+
n
-1).
Input Parameters
uplo
(global)
CHARACTER*1
.
Must be
'U'
or
'L'
.
Specifies whether the distributed matrix sub(
A
) is upper or lower triangular.
If
uplo
=
'U'
, sub(
A
) is upper triangular.
If
uplo
=
'L'
, sub(
A
) is lower triangular.
diag
CHARACTER*1
.
Must be
'N'
or
'U'
.
Specifies whether or not the distributed matrix sub(
A
) is unit triangular.
If
diag
=
'N'
, then sub(
A
) is non-unit triangular.
If
diag
=
'U'
, then sub(
A
) is unit triangular.
n
(global)
INTEGER
.
The number of rows and columns to be operated on, that is, the order of the distributed matrix sub(
A
)
(
n
0)
.
a
(local)
REAL
for
pstrtri
DOUBLE PRECISION
for
pdtrtri
COMPLEX
for
pctrtri
DOUBLE COMPLEX
for
pztrtri
.
Pointer into the local memory to an array of local size
(
lld_a
,
LOCc
(
ja
+
n
-1))
.
The array
a
contains the local pieces of the triangular distributed matrix sub(
A
).
If
uplo
=
'U'
n
-by-
n
upper triangular part of sub(
A
) contains the upper triangular matrix to be inverted, and the strictly lower triangular part of sub(
A
) is not referenced.
If
uplo
=
'L'
n
-by-
n
lower triangular part of sub(
A
) contains the lower triangular matrix, and the strictly upper triangular part of sub(
A
) is not referenced.
ia
,
ja
(global)
INTEGER
.
The row and column indices in the global matrix
A
indicating the first row and the first column of the matrix sub(
A
), respectively.
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