Contents

# p?potri

Computes the inverse of a symmetric/Hermitian positive definite distributed matrix.

## Syntax

Include Files
• mkl_scalapack.h
Description
The
p?potri
function
computes the inverse of a real symmetric or complex Hermitian positive definite distributed matrix sub(
A
) =
A
(
ia
:
ia
+
n
-1,
ja
:
ja
+
n
-1) using the Cholesky factorization sub(
A
) =
U
H
*U
or sub(
A
) =
L*L
H
computed by
p?potrf
.
Input Parameters
uplo
(global) Must be
'U'
or
'L'
.
Specifies whether the upper or lower triangular part of the symmetric/Hermitian matrix sub(
A
) is stored.
If
uplo
=
'U'
, upper triangle of sub(
A
) is stored. If
uplo
=
'L'
, lower triangle of sub(
A
) is stored.
n
(global) The number of rows and columns to be operated on, that is, the order of the distributed matrix sub(
A
)
(
n
0)
.
a
(local)
Pointer into the local memory to an array of local size
lld_a
*
LOCc
(
ja
+
n
-1)
.
On entry, the array
a
contains the local pieces of the triangular factor
U
or
L
from the Cholesky factorization sub(
A
) =
U
H
*U,
or sub(
A
) =
L*L
H
, as computed by
p?potrf
.
ia
,
ja
(global) The row and column indices in the global matrix
A
indicating the first row and the first column of the matrix sub(
A
), respectively.
desca
(global and local) array of size
dlen_
. The array descriptor for the distributed matrix
A
.
Output Parameters
a
On exit, overwritten by the local pieces of the upper or lower triangle of the (symmetric/Hermitian) inverse of sub(
A
).
info
(global) If
info
=0
, the execution is successful.
info
< 0
:
If the
i
-th argument is an array and the
j-
th entry
, indexed
j
- 1,
info
= -(
i
*100+
j
); if the
i-
th argument is a scalar and had an illegal value, then
info
=
-i
.
info
>
0
:
If
info
=
i
, the element (
i
,
i
) of the factor
U
or
L
is zero, and the inverse could not be computed.

#### Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804