sgetri - compute the inverse of a matrix using the LU factorization computed by SGETRF
SUBROUTINE SGETRI( N, A, LDA, IPIVOT, WORK, LDWORK, INFO) INTEGER N, LDA, LDWORK, INFO INTEGER IPIVOT(*) REAL A(LDA,*), WORK(*)
SUBROUTINE SGETRI_64( N, A, LDA, IPIVOT, WORK, LDWORK, INFO) INTEGER*8 N, LDA, LDWORK, INFO INTEGER*8 IPIVOT(*) REAL A(LDA,*), WORK(*)
SUBROUTINE GETRI( [N], A, [LDA], IPIVOT, [WORK], [LDWORK], [INFO]) INTEGER :: N, LDA, LDWORK, INFO INTEGER, DIMENSION(:) :: IPIVOT REAL, DIMENSION(:) :: WORK REAL, DIMENSION(:,:) :: A
SUBROUTINE GETRI_64( [N], A, [LDA], IPIVOT, [WORK], [LDWORK], [INFO]) INTEGER(8) :: N, LDA, LDWORK, INFO INTEGER(8), DIMENSION(:) :: IPIVOT REAL, DIMENSION(:) :: WORK REAL, DIMENSION(:,:) :: A
#include <sunperf.h>
void sgetri(int n, float *a, int lda, int *ipivot, int *info);
void sgetri_64(long n, float *a, long lda, long *ipivot, long *info);
sgetri computes the inverse of a matrix using the LU factorization computed by SGETRF.
This method inverts U and then computes inv(A)
by solving the system
inv(A)*L = inv(U)
for inv(A).
WORK(1)
returns the optimal LDWORK.
If LDWORK = -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 LDWORK is issued by XERBLA.
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
> 0: if INFO = i, U(i,i) is exactly zero; the matrix is singular and its inverse could not be computed.