Developer Reference for Intel® oneAPI Math Kernel Library for C
mkl_?getrinp
Computes the inverse of an LU-factored general matrix without pivoting.
Syntax
lapack_int LAPACKE_mkl_sgetrinp(int matrix_layout, lapack_int n, float *a,
lapack_int lda);
lapack_int LAPACKE_mkl_dgetrinp(int matrix_layout, lapack_int n, double *a,
lapack_int lda);
lapack_int LAPACKE_mkl_cgetrinp(int matrix_layout, lapack_int n, lapack_complex_float *a,
lapack_int lda);
lapack_int LAPACKE_mkl_zgetrinp(int matrix_layout, lapack_int n, lapack_complex_double *a,
lapack_int lda);
Include Files
mkl.h
Description
The routine computes the inverse inv(A) of a general matrix A . Before calling this routine, call mkl_?getrfnp (Computes the LU factorization of a general m-by-n matrix without pivoting.) to factorize A .
Input Parameters
matrix_layout
Specifies whether matrix storage layout is row major ( LAPACK_ROW_MAJOR ) or column major ( LAPACK_COL_MAJOR ).
- n
-
Specifies the order of the matrix A . The value of n must be at least zero.
a , work
Arrays: a(lda,*) , work(*) .
a(lda,*) contains the factorization of the matrix A , as returned by mkl_?getrfnp (Computes the LU factorization of a general m-by-n matrix without pivoting.) : A = L*U .
work(*) is a workspace array of dimension at least max(1,lwork) .
a
Array a (size max(1, lda * n )) contains the factorization of the matrix A , as returned by GUID-9544C788-A2E3-4B56-94CA-04C81C15ADF0.xml : A = L*U . The second dimension of a must be at least max(1,n) .
lda
The leading dimension of a ; lda≥ max(1, n) .
lwork
The size of the work array; lwork ≥ n .
If lwork = -1 , then a workspace query is assumed; the routine only calculates the optimal size of the work array, returns this value as the first entry of the work array, and no error message related to lwork is issued by xerbla .
Output Parameters
a
Overwritten by the n -by- n matrix inv(A) .
work(1)
If info = 0 , on exit work(1) contains the minimum value of lwork required for optimum performance. Use this lwork for subsequent runs.
Return Values
This function returns a value info .
If info = 0 , the execution is successful.
If info = -i , parameter i had an illegal value.
If info = i , the i -th diagonal element of the factor U is zero, U is singular, and the inversion could not be completed.
Application Notes
The total number of floating-point operations is approximately \((4/3)n^{3}\) for real flavors and \((16/3)n^{3}\) for complex flavors.