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spotri

 NAME
      SPOTRI - compute the inverse of a real symmetric positive
      definite matrix A using the Cholesky factorization A =
      U**T*U or A = L*L**T computed by SPOTRF

 SYNOPSIS
      SUBROUTINE SPOTRI( UPLO, N, A, LDA, INFO )

          CHARACTER      UPLO

          INTEGER        INFO, LDA, N

          REAL           A( LDA, * )

 PURPOSE
      SPOTRI computes the inverse of a real symmetric positive
      definite matrix A using the Cholesky factorization A =
      U**T*U or A = L*L**T computed by SPOTRF.

 ARGUMENTS
      UPLO    (input) CHARACTER*1
              = 'U':  Upper triangle of A is stored;
              = 'L':  Lower triangle of A is stored.

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

      A       (input/output) REAL array, dimension (LDA,N)
              On entry, the triangular factor U or L from the
              Cholesky factorization A = U**T*U or A = L*L**T, as
              computed by SPOTRF.  On exit, the upper or lower
              triangle of the (symmetric) inverse of A, overwrit-
              ing the input factor U or L.

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

      INFO    (output) INTEGER
              = 0:  successful exit
              < 0:  if INFO = -i, the i-th argument had an illegal
              value
              > 0:  if INFO = i, the (i,i) element of the factor U
              or L is zero, and the inverse could not be computed.