## Developer Reference

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

# p?pocon

Estimates the reciprocal of the condition number (in the 1 - norm) of a symmetric / Hermitian positive-definite distributed matrix.

## Syntax

Include Files
Description
The
p?pocon
routine
estimates the reciprocal of the condition number (in the 1 - norm) 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
.
An estimate is obtained for ||(sub(
A
))
-1
||
, and the reciprocal of the condition number is computed as Input Parameters
uplo
(global)
CHARACTER*1
.
Must be
'U'
or
'L'
.
Specifies whether the factor stored in sub(
A
) is upper or lower triangular.
If
uplo
=
'U'
, sub(
A
) stores the upper triangular factor
U
of the Cholesky factorization sub(
A
) =
U
H
*U
.
If
uplo
=
'L'
, sub(
A
) stores the lower triangular factor
L
of the Cholesky factorization sub(
A
) =
L*L
H
.
n
(global)
INTEGER
.
The order of the distributed matrix sub(
A
)
(
n
0)
.
a
(local)
REAL
for
pspocon
DOUBLE PRECISION
for
pdpocon
COMPLEX
for
pcpocon
DOUBLE COMPLEX
for
pzpocon
.
Pointer into the local memory to an array of size
(
lld_a
,
LOCc
(
ja
+
n
-1))
.
The array
a
contains the local pieces of the factors
L
or
U
from the Cholesky factorization sub(
A
) =
U
H
*U
, or sub(
A
) =
L*L
H
, as computed by
p?potrf
.
ia
,
ja
(global)