sygvx_scratchpad_size#
Computes size of scratchpad memory required for sygvx
(USM Version)
function. This routine belongs to the oneapi::mkl::lapack
namespace.
Description#
Computes the number of elements of type T
the scratchpad memory to be passed to the sygvx
(buffer or USM version) function must be able to hold.
API#
Syntax#
namespace oneapi::mkl::lapack {
template<typename T>
int64_t sygvx_scratchpad_size(sycl::queue &queue,
int64_t itype,
mkl::job jobz,
mkl::rangev range,
mkl::uplo uplo,
int64_t n,
int64_t lda,
int64_t ldb,
T vl,
T vu,
int64_t il,
int64_t iu,
T abstol,
int64_t ldz)
}
Input Parameters#
- queue
Device queue where calculations by the sygvx (buffer or USM version) function will be performed.
- itype
Must be 1 or 2 or 3. Specifies the problem type to be solved:
if itype
= 1
, the problem type isA*x = lambda*B*x;
if itype
= 2
, the problem type isA*B*x = lambda*x;
if itype
= 3
, the problem type isB*A*x = lambda*x
.- jobz
Must be
job::novec
orjob::vec
.If
jobz = job::novec
, then only eigenvalues are computed.If
jobz = job::vec
, then eigenvalues and eigenvectors are computed.- range
Must be
rangev::all
,rangev::values
orrangev::indices
.If
range = rangev::all
, then all the eigenvalues and eigenvectors (if requested byjobz
parameters) are computed.If
range = rangev::values
, then eigenvalues in the interval(vl, vu]
and corresponding eigenvectors (if requested byjobz
parameters) are computed.If
range = rangev::indices
, then theil
-th throughiu
-th eigenvalues and corresponding eigenvectors (if requested byjobz
parameters) are computed.- uplo
Must be
uplo::upper
oruplo::lower
.If
uplo = uplo::upper
, a and b store the upper triangular part ofA
andB
.If
uplo = uplo::lower
, a and b stores the lower triangular part ofA
andB
.- n
The order of the matrices
A
andB
(0 ≤ n
).- lda
The leading dimension of a. Must be at least
max(1,n)
.- ldb
The leading dimension of b; at least
max(1,n)
.- vl
If
range = rangev::values
, the lower bound of the interval to be searched for eigenvalues.vl
must be less thanvu
. Not referenced ifrange = rangev::all
orrange = rangev::indices
.- vu
If
range = rangev::values
, the upper bound of the interval to be searched for eigenvalues.vl
must be less thanvu
. Not referenced ifrange = rangev::all
orrange = rangev::indices
.- il
If
range = rangev::indices
, the one-based index of the smallest eigenvalue to be returned. Must be1 ≤ il ≤ iu ≤ n
ifn > 0
andil = 1
andiu = 0
ifn = 0
. Not referenced ifrange = rangev::all
orrange = rangev::values
.- iu
If
range = rangev::indices
, the one-based index of the largest eigenvalue to be returned. Must be1 ≤ il ≤ iu ≤ n
ifn > 0
andil = 1
andiu = 0
ifn = 0
. Not referenced ifrange = rangev::all
orrange = rangev::values
.- abstol
The absolute error tolerance for the eigenvalues. An approximate eigenvalue is accepted as converged when it is determined to lie in an interval
[a,b]
of width less than or equal toabstol + eps * max( |a|,|b| )
, whereeps
is the machine precision. Ifabstol
is less than or equal to zero, theneps*|T|
will be used in its place, where|T|
is the 1-norm of the tridiagonal matrix obtained by reducing A to tridiagonal form.- ldz
The leading dimension of z. Must be at least
max(1,n)
.
Exceptions#
Exception |
Description |
---|---|
|
This exception is thrown when an incorrect argument value is supplied. You can determine the position of the incorrect argument by the info() method of the exception object. |
Return Values#
The number of elements of type T
the scratchpad memory to be passed to the sygvx
(buffer or USM version) function must be able to hold.