ungbr_scratchpad_size¶

Computes size of scratchpad memory required for ungbr function.

ungbr_scratchpad_size supports the following precisions.

T

std::complex<float>

std::complex<double>

Description

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

ungbr_scratchpad_size¶

Syntax

template<typename T> std::int64_t onemkl::lapack::ungbr_scratchpad_size(cl::sycl::queue &queue, onemkl::generate gen, std::int64_t m, std::int64_t n, std::int64_t k, std::int64_t lda, std::int64_t &scratchpad_size)¶

Input Parameters

queue

Device queue where calculations by ungbr function will be performed.

gen

Must be generate::q or generate::p.

If gen = generate::q, the routine generates the matrix Q.

If gen = generate::p, the routine generates the matrix P^T.

m

The number of rows in the matrix Q or P^T to be returned (0 ≤ m).

If gen = generate::q, m ≥ n ≥ min(m, k).

If gen = generate::p, n ≥ m ≥ min(n, k).

n

The number of columns in the matrix Q or P^T to be returned (0 ≤ n). See m for constraints.

k

If gen = generate::q, the number of columns in the original m-by-k matrix reduced by gebrd.

If gen = generate::p, the number of rows in the original k-by-n matrix reduced by gebrd.

lda

The leading dimension of a.

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 ungbr function should be able to hold.

Parent topic: LAPACK Singular Value and Eigenvalue Problem Routines