sygvd_scratchpad_size¶

Computes size of scratchpad memory required for sygvd function.

sygvd_scratchpad_size supports the following precisions.

T

float

double

Description

Computes the number of elements of type T the scratchpad memory to be passed to sygvd function should be able to hold. Calls to this routine must specify the template parameter explicitly.

sygvd_scratchpad_size¶

Syntax

template<typename T> std::int64_t onemkl::lapack::sygvd_scratchpad_size(cl::sycl::queue &queue, std::int64_t itype, onemkl::job jobz, onemkl::uplo upper_lower, std::int64_t n, std::int64_t lda, std::int64_t ldb)¶

Input Parameters

queue

Device queue where calculations by sygvd 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 is A*x = lambda*B*x;

if itype = 2, the problem type is A*B*x = lambda*x;

if itype = 3, the problem type is B*A*x = lambda*x.

jobz

Must be job::novec or job::vec.

If jobz = job::novec, then only eigenvalues are computed.

If jobz = job::vec, then eigenvalues and eigenvectors are computed.

upper_lower

Must be uplo::upper or uplo::lower.

If upper_lower = job::upper, a and b store the upper triangular part of A and B.

If upper_lower = job::lower, a and b stores the lower triangular part of A and B.

n

The order of the matrices A and B(0≤n).

lda

The leading dimension of a.

ldb

The leading dimension of b.

Throws

onemkl::lapack::exception: Exception is thrown in case of incorrect argument value is supplied. Position of wrong argument can be determined by get_info() method of exception object.

Return Value

The number of elements of type T the scratchpad memory to be passed to sygvd function should be able to hold.

Parent topic: LAPACK Singular Value and Eigenvalue Problem Routines