zgetri (3p)

Name

zgetri - compute the inverse of a matrix using the LU factorization computed by ZGETRF

Synopsis

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

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

SUBROUTINE ZGETRI_64(N, A, LDA, IPIVOT, WORK, LDWORK, INFO)

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

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

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




C INTERFACE
#include <sunperf.h>

void zgetri(int n, doublecomplex *a, int lda, int *ipivot, int *info);

void zgetri_64(long n, doublecomplex *a, long lda, long  *ipivot,  long
*info);

Description

Oracle Solaris Studio Performance Library                           zgetri(3P)



NAME
       zgetri  -  compute  the  inverse of a matrix using the LU factorization
       computed by ZGETRF


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

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

       SUBROUTINE ZGETRI_64(N, A, LDA, IPIVOT, WORK, LDWORK, INFO)

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

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

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




   C INTERFACE
       #include <sunperf.h>

       void zgetri(int n, doublecomplex *a, int lda, int *ipivot, int *info);

       void zgetri_64(long n, doublecomplex *a, long lda, long  *ipivot,  long
                 *info);



PURPOSE
       zgetri computes the inverse of a matrix using the LU factorization com-
       puted by ZGETRF.

       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 ZGETRF.  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  ZGETRF;  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                        zgetri(3P)