1DPOTRI(1)                LAPACK routine (version 3.1)                DPOTRI(1)
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NAME

6       DPOTRI  -  the  inverse  of a real symmetric positive definite matrix A
7       using the Cholesky factorization A = U**T*U or A = L*L**T  computed  by
8       DPOTRF
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SYNOPSIS

11       SUBROUTINE DPOTRI( UPLO, N, A, LDA, INFO )
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13           CHARACTER      UPLO
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15           INTEGER        INFO, LDA, N
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17           DOUBLE         PRECISION A( LDA, * )
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PURPOSE

20       DPOTRI  computes  the  inverse  of  a  real symmetric positive definite
21       matrix A using the Cholesky factorization A = U**T*U or A = L*L**T com‐
22       puted by DPOTRF.
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ARGUMENTS

26       UPLO    (input) CHARACTER*1
27               = 'U':  Upper triangle of A is stored;
28               = 'L':  Lower triangle of A is stored.
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30       N       (input) INTEGER
31               The order of the matrix A.  N >= 0.
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33       A       (input/output) DOUBLE PRECISION array, dimension (LDA,N)
34               On  entry,  the triangular factor U or L from the Cholesky fac‐
35               torization A = U**T*U or A = L*L**T, as computed by DPOTRF.  On
36               exit, the upper or lower triangle of the (symmetric) inverse of
37               A, overwriting the input factor U or L.
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39       LDA     (input) INTEGER
40               The leading dimension of the array A.  LDA >= max(1,N).
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42       INFO    (output) INTEGER
43               = 0:  successful exit
44               < 0:  if INFO = -i, the i-th argument had an illegal value
45               > 0:  if INFO = i, the (i,i) element of the factor U  or  L  is
46               zero, and the inverse could not be computed.
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50 LAPACK routine (version 3.1)    November 2006                       DPOTRI(1)
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