?getri_oop_batch

Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

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ID 766686

Date 4/28/2026

Version

Public

?getri_oop_batch_strided

Computes the inverses of a group of LU factored matrices that are stored at a constant stride from each other in a contiguous block of memory.

Syntax

call sgetri_oop_batch_strided ( n , A , lda , stride_a , ipiv , stride_ipiv , Ainv , ldainv , stride_ainv , batch_size , info )

call dgetri_oop_batch_strided ( n , A , lda , stride_a , ipiv , stride_ipiv , Ainv , ldainv , stride_ainv , batch_size , info )

call cgetri_oop_batch_strided ( n , A , lda , stride_a , ipiv , stride_ipiv , Ainv , ldainv , stride_ainv , batch_size , info )

call zgetri_oop_batch_strided ( n , A , lda , stride_a , ipiv , stride_ipiv , Ainv , ldainv , stride_ainv , batch_size , info )

Include Files

mkl.fi

Description

The ?getri_oop_batch_strided routines are similar to the ?getri counterparts, but instead compute the inverses for a group of LU factored matrices.

All matrices have the same parameters (matrix size, leading dimension) and are stored at constant stride_a from each other in a contiguous block of memory. The output arrays are stored at constant stride_ainv from each other in a contiguous block of memory. Their respective pivot arrays associated with each of the LU-factored A(i) matrices are stored at constant stride_ipiv from each other.

The operation is defined as

for i = 0 … batch_size-1
     A(i) is a matrix at offset i * stride_a from A
     ipiv(i) is an array at offset i * stride_ipiv from ipiv
     Ainv(i) is a matrix at offset i * stride_ainv from Ainv
     Ainv(i) :=  inv(P(i) * L(i)* U(i))
end for

where P(i) is a permutation matrix, L(i) is lower triangular with unit diagonal elements (lower trapezoidal if m > n ), and U(i) is upper triangular (upper trapezoidal if m < n ). The routine uses partial pivoting, with row interchanges.

Input Parameters

n

INTEGER . The number of columns in the A(i) matrices; n ≥ 0.

A: REAL for sgetri_oop_batch_strided DOUBLE PRECISION for dgetri_oop_batch_strided COMPLEX for cgetri_oop_batch_strided DOUBLE COMPLEX for zgetri_oop_batch_strided The A array of size at least stride_a * batch_size holding the A(i) matrices.

lda

INTEGER . Specifies the leading dimension of the A(i) matrices; lda ≥ n .

stride_a

INTEGER . Stride between two consecutive A(i) matrices; ; stride_a ≥ lda * n .

ipiv: Array of size at least stride_ipiv * batch_size , holding the pivot array associated with each of the LU-factored A(i) matrices, as returned by ?getrf_batch_strided .
stride_ipiv: Stride between two consecutive pivot arrays; stride_ipiv ≥ n .

ldainv

INTEGER . Specifies the leading dimension of the Ainv(i) matrices; ldainv ≥ n .

stride_ainv

INTEGER . Stride between two consecutive Ainv(i) matrices; ; stride_ainv ≥ ldainv * n .

batch_size: INTEGER . Number of A(i) matrices to be factorized. Must be at least 0.

Output Parameters

Ainv: Array holding the inverses Ainv(i) matrices. Each matrix is overwritten by their respective L(i) and U(i) factors. The unit diagonal elements of L are not stored.

info

INTEGER .

Array of size batch_size , which reports the factorization status for each matrix.
If info(i) = 0, the execution is successful for A(i) .
If info(i) = - j , the j -th parameter had an illegal value for A(i) .
If info(i) = j , the j -th diagonal element of the factor U(i) is 0, U(i) is exactly singular. Division by - will occur if you use the factor U(i) to solve a system of linear equations.

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