Description

API

namespace oneapi::mkl::lapack {
  cl::sycl::event geqrf_batch(cl::sycl::queue &queue,
  std::int64_t *m,
  std::int64_t *n,
  T **a,
  std::int64_t *lda,
  T **tau,
  std::int64_t group_count,
  std::int64_t *group_sizes,
  T *scratchpad,
  std::int64_t scratchpad_size,
  const std::vector<cl::sycl::event> &events = {})
}

queue

Device queue where calculations will be performed.

m

Array of

group_count

parameters m

g

parameters.

Each of m

g

specifies the number of rows in the matrices

A

i

from array

a

, belonging to group

g

.

n

Array of

group_count

parameters n

g

parameters.

Each of n

g

specifies the number of columns in the matrices

A

i

from array

a

, belonging to group

g

.

a

Array of

batch_size

pointers to input matrices

A

i

, each being of size

lda

g

*

n

g

(

g

is an index of group to which

A

i

belongs).

lda

Array of

group_count

lda

g

parameters, each representing the leading dimensions of input matrices

A

i

, from array

a

, belonging to group

g

.

group_count

Specifies the number of groups of parameters. Must be at least 0.

group_sizes

Array of group_count integers. Array element with index

g

specifies the number of problems to solve for each of the groups of parameters

g

. So the total number of problems to solve,

batch_size

, is a sum of all parameter group sizes.

scratchpad

Scratchpad memory to be used by 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 then the value returned by geqrf_batch_scratchpad_size (Group Version).

events

List of events to wait for before starting computation. Defaults to empty list.

a

Matrices pointed to by array

a

are overwritten by the factorization data as follows:

The elements on and above the diagonal of

A

i

contain the

min(mg,mng)

-by-

n

g

upper trapezoidal matrices

R

i

(

R

i

is upper triangular if

mg≥ng

); the elements below the diagonal, with the array

tau

i

, present the orthogonal matrix

Q

i

as a rpoduct of

min(mg,ng)

elementary reflectors.

Here,

g

is an index of parameters group corresponding to

i

-th decomposition.

tau

Array of pointers to store

tau

i

, each of size

m

g

,

n

g

, containing scalars that define elementary reflectors for the matrices

Q

i

in its decomposition in a product of elementary reflectors.

Here,

g

is an index of parameters group corresponding to

i

-th decomposition.