unmtr_scratchpad_size

Computes size of scratchpad memory required for unmtr function.

Description

unmtr_scratchpad_size supports the following precisions.

T
std::complex<float>
std::complex<double>

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

unmtr_scratchpad_size

Syntax

namespace oneapi::mkl::lapack {
  template <typename T>
  std::int64_t unmtr_scratchpad_size(sycl::queue &queue, oneapi::mkl::side side, oneapi::mkl::uplo upper_lower, oneapi::mkl::transpose trans, std::int64_t m, std::int64_t n, std::int64_t lda, std::int64_t ldc)
}

Input Parameters

queue

Device queue where calculations by unmtr function will be performed.

side

Must be either side::left or side::right.

If side=side::left, \(Q\) or \(Q^{H}\) is applied to \(C\) from the left.

If side=side::right, \(Q\) or \(Q^{H}\) is applied to \(C\) from the right.

upper_lower

Must be either uplo::upper or uplo::lower. Uses the same upper_lower as supplied to hetrd.

trans

Must be either transpose::nontrans or transpose::conjtrans.

If trans=transpose::nontrans, the routine multiplies \(C\) by \(Q\).

If trans=transpose::conjtrans, the routine multiplies \(C\) by \(Q^{H}\).

m

The number of rows in the matrix \(C\) (\(m \ge 0\)).

n

The number of columns the matrix \(C\) (\(n \ge 0\)).

k

The number of elementary reflectors whose product defines the matrix \(Q\) (\(0 \le k \le n\)).

lda

The leading dimension of \(a\) \((\max(1,r) \le \text{lda})\).

ldc

The leading dimension of \(c\) \((\max(1,n) \le \text{ldc})\).

Return Value

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

Parent topic: LAPACK Singular Value and Eigenvalue Problem Routines