cgetri (3p)

Name

cgetri - compute the inverse of a matrix using the LU factorization computed by CGETRF

Synopsis

SUBROUTINE CGETRI(N, A, LDA, IPIVOT, WORK, LDWORK, INFO)

COMPLEX A(LDA,*), WORK(*)
INTEGER N, LDA, LDWORK, INFO
INTEGER IPIVOT(*)

SUBROUTINE CGETRI_64(N, A, LDA, IPIVOT, WORK, LDWORK, INFO)

COMPLEX A(LDA,*), WORK(*)
INTEGER*8 N, LDA, LDWORK, INFO
INTEGER*8 IPIVOT(*)




F95 INTERFACE
SUBROUTINE GETRI(N, A, LDA, IPIVOT, WORK, LDWORK, INFO)

COMPLEX, DIMENSION(:) :: WORK
COMPLEX, DIMENSION(:,:) :: A
INTEGER :: N, LDA, LDWORK, INFO
INTEGER, DIMENSION(:) :: IPIVOT

SUBROUTINE GETRI_64(N, A, LDA, IPIVOT, WORK, LDWORK, INFO)

COMPLEX, DIMENSION(:) :: WORK
COMPLEX, DIMENSION(:,:) :: A
INTEGER(8) :: N, LDA, LDWORK, INFO
INTEGER(8), DIMENSION(:) :: IPIVOT




C INTERFACE
#include <sunperf.h>

void cgetri(int n, complex *a, int lda, int *ipivot, int *info);

void cgetri_64(long n, complex *a, long lda, long *ipivot, long *info);

Description

Oracle Solaris Studio Performance Library                           cgetri(3P)



NAME
       cgetri  -  compute  the  inverse of a matrix using the LU factorization
       computed by CGETRF


SYNOPSIS
       SUBROUTINE CGETRI(N, A, LDA, IPIVOT, WORK, LDWORK, INFO)

       COMPLEX A(LDA,*), WORK(*)
       INTEGER N, LDA, LDWORK, INFO
       INTEGER IPIVOT(*)

       SUBROUTINE CGETRI_64(N, A, LDA, IPIVOT, WORK, LDWORK, INFO)

       COMPLEX A(LDA,*), WORK(*)
       INTEGER*8 N, LDA, LDWORK, INFO
       INTEGER*8 IPIVOT(*)




   F95 INTERFACE
       SUBROUTINE GETRI(N, A, LDA, IPIVOT, WORK, LDWORK, INFO)

       COMPLEX, DIMENSION(:) :: WORK
       COMPLEX, DIMENSION(:,:) :: A
       INTEGER :: N, LDA, LDWORK, INFO
       INTEGER, DIMENSION(:) :: IPIVOT

       SUBROUTINE GETRI_64(N, A, LDA, IPIVOT, WORK, LDWORK, INFO)

       COMPLEX, DIMENSION(:) :: WORK
       COMPLEX, DIMENSION(:,:) :: A
       INTEGER(8) :: N, LDA, LDWORK, INFO
       INTEGER(8), DIMENSION(:) :: IPIVOT




   C INTERFACE
       #include <sunperf.h>

       void cgetri(int n, complex *a, int lda, int *ipivot, int *info);

       void cgetri_64(long n, complex *a, long lda, long *ipivot, long *info);



PURPOSE
       cgetri computes the inverse of a matrix using the LU factorization com-
       puted by CGETRF.

       This method inverts U and then computes inv(A) by  solving  the  system
       inv(A)*L = inv(U) for inv(A).


ARGUMENTS
       N (input) The order of the matrix A.  N >= 0.


       A (input/output)
                 On  entry,  the  factors  L  and U from the factorization A =
                 P*L*U as computed by CGETRF.  On  exit,  if  INFO  =  0,  the
                 inverse of the original matrix A.


       LDA (input)
                 The leading dimension of the array A.  LDA >= max(1,N).


       IPIVOT (input)
                 The  pivot  indices  from  CGETRF;  for 1<=i<=N, row i of the
                 matrix was interchanged with row IPIVOT(i).


       WORK (workspace)
                 On exit, if INFO=0, then WORK(1) returns the optimal  LDWORK.


       LDWORK (input)
                 The  dimension  of  the array WORK.  LDWORK >= max(1,N).  For
                 optimal performance LDWORK >= N*NB, where NB is  the  optimal
                 blocksize returned by ILAENV.

                 If  LDWORK  = -1, then a workspace query is assumed; the rou-
                 tine 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.


       INFO (output)
                 = 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 sin-
                 gular and its inverse could not be computed.




                                  7 Nov 2015                        cgetri(3P)