1CPPTRI(1)                LAPACK routine (version 3.2)                CPPTRI(1)
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NAME

6       CPPTRI  - computes the inverse of a complex Hermitian positive definite
7       matrix A using the Cholesky factorization A = U**H*U or A = L*L**H com‐
8       puted by CPPTRF
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SYNOPSIS

11       SUBROUTINE CPPTRI( UPLO, N, AP, INFO )
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13           CHARACTER      UPLO
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15           INTEGER        INFO, N
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17           COMPLEX        AP( * )
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PURPOSE

20       CPPTRI  computes  the  inverse of a complex Hermitian positive definite
21       matrix A using the Cholesky factorization A = U**H*U or A = L*L**H com‐
22       puted by CPPTRF.
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ARGUMENTS

25       UPLO    (input) CHARACTER*1
26               = 'U':  Upper triangular factor is stored in AP;
27               = 'L':  Lower triangular factor is stored in AP.
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29       N       (input) INTEGER
30               The order of the matrix A.  N >= 0.
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32       AP      (input/output) COMPLEX array, dimension (N*(N+1)/2)
33               On  entry,  the triangular factor U or L from the Cholesky fac‐
34               torization A = U**H*U or A = L*L**H,  packed  columnwise  as  a
35               linear array.  The j-th column of U or L is stored in the array
36               AP as follows: if UPLO = 'U', AP(i + (j-1)*j/2)  =  U(i,j)  for
37               1<=i<=j;  if  UPLO  =  'L', AP(i + (j-1)*(2n-j)/2) = L(i,j) for
38               j<=i<=n.  On exit, the upper or lower triangle of the  (Hermit‐
39               ian) inverse of A, overwriting the input factor U or L.
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41       INFO    (output) INTEGER
42               = 0:  successful exit
43               < 0:  if INFO = -i, the i-th argument had an illegal value
44               >  0:   if  INFO = i, the (i,i) element of the factor U or L is
45               zero, and the inverse could not be computed.
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49 LAPACK routine (version 3.2)    November 2008                       CPPTRI(1)
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