unmrq (USM Version)#
Multiplies a complex matrix by the unitary matrix Q of the RQ
factorization formed by the gerqf (USM Version) function. This routine
belongs to the oneapi::mkl::lapack namespace.
Description#
The routine multiplies a complex m-by-n matrix C by Q
or QT, where Q is the orthogonal matrix Q of the
RQ factorization formed by the routine gerqf (USM Version) .
Depending on the parameters side and trans, the routine can
form one of the matrix products Q*C, QT*C,
C*Q, or C*QT (overwriting the result over C).
API#
Syntax#
namespace oneapi::mkl::lapack {
sycl::event unmrq(sycl::queue &queue,
mkl::side side,
mkl::transpose trans,
int64_t m,
int64_t n,
int64_t k,
const T *a,
int64_t lda,
const T *tau,
T *c,
int64_t ldc,
T *scratchpad,
int64_t scratchpad_size,
const std::vector<sycl::event> &events = {})
}
unmrq (USM version) supports the following precisions and devices:
T |
Devices supported |
|---|---|
|
CPU |
|
CPU |
Input Parameters#
- queue
Device queue where calculations will be performed.
- side
If
side=mkl::side::left,QorQT is applied toCfrom the left. Ifside=mkl::side::right,QorQT is applied toCfrom the right.- trans
If
trans=mkl::transpose::trans, the routine multipliesCbyQ.If
trans=mkl::transpose::nontrans, the routine multipliesCbyQT.- m
The number of rows in the matrix
A(0 ≤ m).- n
The number of columns in the matrix
A(0 ≤ n ≤ m).- k
The number of elementary reflectors whose product defines the matrix
Q(0 ≤ k ≤ n).- a
The pointer to the result of the gerqf (USM Version) function. The size of
amust be at leastlda*k.- lda
The leading dimension of a.
- tau
The pointer to tau returned by the gerqf (USM Version) function.
- c
The pointer to the matrix
C. The size of c must be at leastldc*n.- ldc
The leading dimension of c.
- scratchpad
Pointer to scratchpad memory to be used by the routine for storing intermediate results.
- scratchpad_size
Size of scratchpad memory as a number of floating point elements of type
T. Size should not be less than the value returned by the unmrq_scratchpad_size function.- events
List of events to wait for before starting computation. Defaults to empty list.
Output Parameters#
- c
Overwritten by the product
Q*C,QT*C,C*Q, orC*QT (as specified by side and trans).
Exceptions#
Exception |
Description |
|---|---|
|
This exception is thrown when problems occur during calculations. You can obtain the info code of the problem using the info() method of the exception object: If If |
Return Values#
Output event to wait on to ensure computation is complete.