heevx_scratchpad_size#
Computes size of scratchpad memory required for heevx (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 heevx (buffer or USM version) function must be able to hold.
API#
Syntax#
namespace oneapi::mkl::lapack {
template<typename T>
int64_t heevx_scratchpad_size(sycl::queue &queue,
mkl::job jobz,
mkl::rangev range,
mkl::uplo uplo,
int64_t n,
int64_t lda,
T::value_type vl,
T::value_type vu,
int64_t il,
int64_t iu,
T::value_type abstol,
int64_t ldz)
}
Input Parameters#
- queue
Device queue where calculations by the heevx (buffer or USM version) function will be performed.
- jobz
Must be
job::novecorjob::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::valuesorrangev::indices.If
range = rangev::all, then all the eigenvalues and eigenvectors (if requested byjobzparameters) are computed.If
range = rangev::values, then eigenvalues in the interval(vl, vu]and corresponding eigenvectors (if requested byjobzparameters) are computed.If
range = rangev::indices, then theil-th throughiu-th eigenvalues and corresponding eigenvectors (if requested byjobzparameters) are computed.- uplo
Must be
uplo::upperoruplo::lower.If
uplo = uplo::upper, a stores the upper triangular part ofA.If
uplo = uplo::lower, a stores the lower triangular part ofA.- n
The order of the matrix
A(0 ≤ n).- lda
The leading dimension of a. Must be at least
max(1,n).- vl
If
range = rangev::values, the lower bound of the interval to be searched for eigenvalues.vlmust be less thanvu. Not referenced ifrange = rangev::allorrange = rangev::indices.- vu
If
range = rangev::values, the upper bound of the interval to be searched for eigenvalues.vlmust be less thanvu. Not referenced ifrange = rangev::allorrange = rangev::indices.- il
If
range = rangev::indices, the one-based index of the smallest eigenvalue to be returned. Must be1 ≤ il ≤ iu ≤ nifn > 0andil = 1andiu = 0ifn = 0. Not referenced ifrange = rangev::allorrange = rangev::values.- iu
If
range = rangev::indices, the one-based index of the largest eigenvalue to be returned. Must be1 ≤ il ≤ iu ≤ nifn > 0andil = 1andiu = 0ifn = 0. Not referenced ifrange = rangev::allorrange = 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| ), whereepsis the machine precision. Ifabstolis 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 heevx (buffer or USM version) function must be able to hold.