Developer Reference

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

?tpcon

Estimates the reciprocal of the condition number of a packed triangular matrix.

Syntax

call stpcon
(
norm
,
uplo
,
diag
,
n
,
ap
,
rcond
,
work
,
iwork
,
info
)
call dtpcon
(
norm
,
uplo
,
diag
,
n
,
ap
,
rcond
,
work
,
iwork
,
info
)
call ctpcon
(
norm
,
uplo
,
diag
,
n
,
ap
,
rcond
,
work
,
rwork
,
info
)
call ztpcon
(
norm
,
uplo
,
diag
,
n
,
ap
,
rcond
,
work
,
rwork
,
info
)
call tpcon
(
ap
,
rcond
[
,
uplo
]
[
,
diag
]
[
,
norm
]
[
,
info
]
)
Include Files
  • mkl.fi
    ,
    lapack.f90
Description
The routine estimates the reciprocal of the condition number of a packed triangular matrix
A
in either the 1-norm or infinity-norm:
κ
1
(
A
) =||
A
||
1
||
A
-1
||
1
=
κ
(
A
T
) =
κ
(
A
H
)
κ
(
A
) =||
A
||
||
A
-1
||
=
κ
1
(
A
T
) =
κ
1
(
A
H
) .
Input Parameters
norm
CHARACTER*1
.
Must be
'1'
or
'O'
or
'I'
.
If
norm
=
'1'
or
'O'
, then the routine estimates the condition number of matrix
A
in 1-norm.
If
norm
=
'I'
, then the routine estimates the condition number of matrix
A
in infinity-norm.
uplo
CHARACTER*1
.
Must be
'U'
or
'L'
. Indicates whether
A
is upper or lower triangular:
If
uplo
=
'U'
, the array
ap
stores the upper triangle of
A
in packed form.
If
uplo
=
'L'
, the array
ap
stores the lower triangle of
A
in packed form.
diag
CHARACTER*1
.
Must be
'N'
or
'U'
.
If
diag
=
'N'
, then
A
is not a unit triangular matrix.
If
diag
=
'U'
, then
A
is unit triangular: diagonal elements are assumed to be 1 and not referenced in the array
ap
.
n
INTEGER
.
The order of the matrix
A
;
n
0.
ap