Developer Reference

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

?larrr

Performs tests to decide whether the symmetric tridiagonal matrix
T
warrants expensive computations which guarantee high relative accuracy in the eigenvalues.

Syntax

call slarrr
(
n
,
d
,
e
,
info
)
call dlarrr
(
n
,
d
,
e
,
info
)
Include Files
  • mkl.fi
Description
The routine performs tests to decide whether the symmetric tridiagonal matrix
T
warrants expensive computations which guarantee high relative accuracy in the eigenvalues.
Input Parameters
n
INTEGER
. The order of the matrix
T
. (
n
>
0
).
d
REAL
for
slarrr
DOUBLE PRECISION
for
dlarrr
Array,
DIMENSION
(
n
).
Contains
n
diagonal elements of the matrix
T
.
e
REAL
for
slarrr
DOUBLE PRECISION
for
dlarrr
Array,
DIMENSION
(
n
).
The first
(
n
-1)
entries contain sub-diagonal elements of the tridiagonal matrix
T
;
e
(
n
)
is set to 0.
Output Parameters
info
INTEGER
.
= 0:
the matrix warrants computations preserving relative accuracy (default value).
= -1:
the matrix warrants computations guaranteeing only absolute accuracy.

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