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

6       CPOTRF  -  the  Cholesky  factorization of a complex Hermitian positive
7       definite matrix A
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SYNOPSIS

10       SUBROUTINE CPOTRF( UPLO, N, A, LDA, INFO )
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12           CHARACTER      UPLO
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14           INTEGER        INFO, LDA, N
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16           COMPLEX        A( LDA, * )
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PURPOSE

19       CPOTRF computes the Cholesky factorization of a complex Hermitian posi‐
20       tive definite matrix A.
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22       The factorization has the form
23          A = U**H * U,  if UPLO = 'U', or
24          A = L  * L**H,  if UPLO = 'L',
25       where U is an upper triangular matrix and L is lower triangular.
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27       This is the block version of the algorithm, calling Level 3 BLAS.
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ARGUMENTS

31       UPLO    (input) CHARACTER*1
32               = 'U':  Upper triangle of A is stored;
33               = 'L':  Lower triangle of A is stored.
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35       N       (input) INTEGER
36               The order of the matrix A.  N >= 0.
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38       A       (input/output) COMPLEX array, dimension (LDA,N)
39               On  entry,  the Hermitian matrix A.  If UPLO = 'U', the leading
40               N-by-N upper triangular part of A contains the upper triangular
41               part of the matrix A, and the strictly lower triangular part of
42               A is not referenced.  If UPLO = 'L', the leading  N-by-N  lower
43               triangular  part of A contains the lower triangular part of the
44               matrix A, and the strictly upper triangular part of  A  is  not
45               referenced.
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47               On  exit, if INFO = 0, the factor U or L from the Cholesky fac‐
48               torization A = U**H*U or A = L*L**H.
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50       LDA     (input) INTEGER
51               The leading dimension of the array A.  LDA >= max(1,N).
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53       INFO    (output) INTEGER
54               = 0:  successful exit
55               < 0:  if INFO = -i, the i-th argument had an illegal value
56               > 0:  if INFO = i, the leading minor of order i is not positive
57               definite, and the factorization could not be completed.
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61 LAPACK routine (version 3.1)    November 2006                       CPOTRF(1)
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