Developer Reference

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

?la_gerpvgrw

Computes the reciprocal pivot growth factor
norm(A)/norm(U)
for a general matrix.

Syntax

call sla_gerpvgrw
(
n
,
ncols
,
a
,
lda
,
af
,
ldaf
)
call dla_gerpvgrw
(
n
,
ncols
,
a
,
lda
,
af
,
ldaf
)
call cla_gerpvgrw
(
n
,
ncols
,
a
,
lda
,
af
,
ldaf
)
call zla_gerpvgrw
(
n
,
ncols
,
a
,
lda
,
af
,
ldaf
)
Include Files
  • mkl.fi
Description
The
?la_gerpvgrw
routine computes the reciprocal pivot growth factor
norm(
A
)/norm(
U
)
. The max absolute element norm is used. If this is much less than 1, the stability of the
LU
factorization of the equilibrated matrix
A
could be poor. This also means that the solution
X
, estimated condition numbers, and error bounds could be unreliable.
Input Parameters
n
INTEGER
. The number of linear equations, the order of the matrix
A
;
n
0.
ncols
INTEGER
. The number of columns of the matrix
A
;
ncols
0.
a
,
af
REAL
for
sla_gerpvgrw
DOUBLE PRECISION
for
dla_gerpvgrw
COMPLEX
for
cla_gerpvgrw
DOUBLE COMPLEX
for
zla_gerpvgrw
.
Arrays:
a
(
lda
,*)
,
af
(
ldaf
,*)
.
The array
a
contains the input
n
-by-
n
matrix
A
. The second dimension of
a
must be at least
max(1,
n
)
.
The array
af
contains the factors L and U from the factorization triangular factor
L
or
U
from the Cholesky factorization
A = P*L*U
as computed by
?getrf
. The second dimension of
af
must be at least
max(1,
n
)
.
lda
INTEGER
. The leading dimension of
a
;
lda
max(1,
n
)
.
ldaf
INTEGER
. The leading dimension of
af
;
ldaf
max(1,
n
)
.

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