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,
               overwriting 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 ille­
               gal value
               > 0:  if INFO = i, the (i,i) element of the factor
               U or L is zero, and the inverse could not be  com­
               puted.


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