Contents

getri

Computes the inverse of an LU-factored general matrix determined by getrf. This routine belongs to the oneapi::mkl::lapack namespace.

Description

The routine computes the inverse inv(A) of a general matrix A. Before calling this routine, call getrf to factorize A.

API

Syntax

 namespace oneapi::mkl::lapack {
   void getri(cl::sycl::queue &queue,
   std::int64_t n,
   cl::sycl::buffer<T> &a,
   std::int64_t lda,
   std::int64_t *ipiv,
   cl::sycl::buffer<T> &scratchpad, std::int64_t scratchpad_size)
}

getri supports the following precisions and devices:

T

Devices supported

float

Host, CPU, and GPU

double

Host, CPU, and GPU

std::complex<float>

Host, CPU, and GPU

std::complex<double>

Host, CPU, and GPU

Input Parameters

queue

Device queue where calculations will be performed.

n

The order of the matrix A(0≤n).

a

The buffer returned by getrf. Must be of size at least lda*max(1,n).

lda

The leading dimension of a(n≤lda).

ipiv

The array as returned by getrf. The dimension of ipiv must be at least max(1, n).

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 getri_scratchpad_size function.

Output Parameters

a

Overwritten by the n-by-n matrix A.

Exceptions

Exception

Description

mkl::lapack::exception

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 info = -i, the i-th parameter had an illegal value.

If info is equal to the value passed as scratchpad size, and detail() returns non zero, then the passed scratchpad has an insufficient size, and the required size should not be less than the value returned by the detail() method of the exception object.

Known Limitations

  • GPU support is for only real precisions.

  • For GPU support, errors are reported through the info parameter, but computation does not halt for an algorithmic error.

getrf_scratchpad_size getri (USM Version)