CPOFA(3)

SYNOPSIS
SUBROUTINE CPOFA (A, LDA, N, INFO)

NAME
cpofa - Factor a complex Hermitian positive definite matrix.

LIBRARY
SLATEC (LINPACK)

CATEGORY
D2D1B

TYPE
COMPLEX (SPOFA-S, DPOFA-D, CPOFA-C)

KEYWORDS
LINEAR ALGEBRA, LINPACK, MATRIX FACTORIZATION, POSITIVE DEFINITE

AUTHOR
Moler, C. B., (U. of New Mexico)

DESCRIPTION
CPOFA factors a complex Hermitian positive definite matrix. CPOFA is usually called by CPOCO, but it can be called directly with a saving in time if RCOND is not needed. (Time for CPOCO) = (1 + 18/N)*(Time for CPOFA) . On Entry A COMPLEX(LDA, N) the Hermitian matrix to be factored. Only the diagonal and upper triangle are used. LDA INTEGER the leading dimension of the array A . N INTEGER the order of the matrix A . On Return A an upper triangular matrix R so that A = CTRANS(R)*R where CTRANS(R) is the conjugate transpose. The strict lower triangle is unaltered. If INFO .NE. 0 , the factorization is not complete. INFO INTEGER = 0 for normal return. = K signals an error condition. The leading minor of order K is not positive definite.

REFERENCES
J. J. Dongarra, J. R. Bunch, C. B. Moler, and G. W. Stewart, LINPACK Users' Guide, SIAM, 1979.

ROUTINES CALLED
CDOTC

REVISION HISTORY (YYMMDD)
780814 DATE WRITTEN
890831 Modified array declarations. (WRB)
890831 REVISION DATE from Version 3.2
891214 Prologue converted to Version 4.0 format. (BAB)
900326 Removed duplicate information from DESCRIPTION section. (WRB)
920501 Reformatted the REFERENCES section. (WRB)