Developer Reference

  • 098
  • 03/30/2020
  • Public Content
Contents

?roti

Applies Givens rotation to sparse vectors one of which is in compressed form.

Syntax

call sroti
(
nz
,
x
,
indx
,
y
,
c
,
s
)
call droti
(
nz
,
x
,
indx
,
y
,
c
,
s
)
call roti
(
x
,
indx
,
y
,
c
,
s
)
Include Files
  • mkl.fi
    ,
    blas.f90
Description
The
?roti
routines apply the Givens rotation to elements of two real vectors,
x
(in compressed form
nz
,
x
,
indx
) and
y
(in full storage form):
x
(
i
) =
c*x
(
i
) +
s*y
(
indx
(
i
))
y
(
indx
(
i
)) =
c*y
(
indx
(
i
))-
s*x
(
i
)
The routines reference only the elements of
y
whose indices are listed in the array
indx
. The values in
indx
must be distinct.
Input Parameters
nz
INTEGER
.
The number of elements in
x
and
indx
.
x
REAL
for
sroti
DOUBLE PRECISION
for
droti
Array, size at least
nz
.
indx
INTEGER
.
Specifies the indices for the elements of
x
.
Array, size at least
nz
.
y
REAL
for
sroti
DOUBLE PRECISION
for
droti
Array, size at least max(
indx(i)
).
c
REAL
for
sroti
DOUBLE PRECISION
for
droti
.
A scalar.
s
REAL
for
sroti
DOUBLE PRECISION
for
droti
.
A scalar.
Output Parameters
x
and
y
The updated arrays.
BLAS 95 Interface Notes
Routines in Fortran 95 interface have fewer arguments in the calling sequence than their FORTRAN 77 counterparts. For general conventions applied to skip redundant or reconstructible arguments, see BLAS 95 Interface Conventions .
Specific details for the routine
roti
interface are the following:
x
Holds the vector with the number of elements
nz
.
indx
Holds the vector with the number of elements
nz
.
y
Holds the vector with the number of elements
nz
.

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