CXML
        	    
LAPACK version 3.0
csptri(3)

PURPOSE
  CSPTRI - compute the inverse of a complex symmetric indefinite matrix A in
  packed storage using the factorization A = U*D*U**T or A = L*D*L**T
  computed by CSPTRF

SYNTAX
  SUBROUTINE CSPTRI( UPLO, N, AP, IPIV, WORK, INFO )

      CHARACTER	     UPLO

      INTEGER	     INFO, N

      INTEGER	     IPIV( * )

      COMPLEX	     AP( * ), WORK( * )

DESCRIPTION
  CSPTRI computes the inverse of a complex symmetric indefinite matrix A in
  packed storage using the factorization A = U*D*U**T or A = L*D*L**T
  computed by CSPTRF.

ARGUMENTS
  UPLO	  (input) CHARACTER*1
	  Specifies whether the details of the factorization are stored as an
	  upper or lower triangular matrix.  = 'U':  Upper triangular, form
	  is A = U*D*U**T;
	  = 'L':  Lower triangular, form is A = L*D*L**T.

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

  AP	  (input/output) COMPLEX array, dimension (N*(N+1)/2)
	  On entry, the block diagonal matrix D and the multipliers used to
	  obtain the factor U or L as computed by CSPTRF, stored as a packed
	  triangular matrix.

	  On exit, if INFO = 0, the (symmetric) inverse of the original
	  matrix, stored as a packed triangular matrix. The j-th column of
	  inv(A) is stored in the array AP as follows: if UPLO = 'U', AP(i +
	  (j-1)*j/2) = inv(A)(i,j) for 1<=i<=j; if UPLO = 'L', AP(i + (j-
	  1)*(2n-j)/2) = inv(A)(i,j) for j<=i<=n.

  IPIV	  (input) INTEGER array, dimension (N)
	  Details of the interchanges and the block structure of D as
	  determined by CSPTRF.

  WORK	  (workspace) COMPLEX array, dimension (N)

  INFO	  (output) INTEGER
	  = 0: successful exit
	  < 0: if INFO = -i, the i-th argument had an illegal value
	  > 0: if INFO = i, D(i,i) = 0; the matrix is singular and its
	  inverse could not be computed.