CPOSL(3)

SYNOPSIS
SUBROUTINE CPOSL (A, LDA, N, B)

NAME
cposl - Solve the complex Hermitian positive definite linear system using the factors computed by CPOCO or CPOFA.

LIBRARY
SLATEC (LINPACK)

CATEGORY
D2D1B

TYPE
COMPLEX (SPOSL-S, DPOSL-D, CPOSL-C)

KEYWORDS
LINEAR ALGEBRA, LINPACK, MATRIX, POSITIVE DEFINITE, SOLVE

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

DESCRIPTION
CPOSL solves the COMPLEX Hermitian positive definite system A * X = B using the factors computed by CPOCO or CPOFA. On Entry A COMPLEX(LDA, N) the output from CPOCO or CPOFA. LDA INTEGER the leading dimension of the array A . N INTEGER the order of the matrix A . B COMPLEX(N) the right hand side vector. On Return B the solution vector X . Error Condition A division by zero will occur if the input factor contains a zero on the diagonal. Technically this indicates singularity but it is usually caused by improper subroutine arguments. It will not occur if the subroutines are called correctly and INFO .EQ. 0 . To compute INVERSE(A) * C where C is a matrix with P columns CALL CPOCO(A,LDA,N,RCOND,Z,INFO) IF (RCOND is too small .OR. INFO .NE. 0) GO TO ... DO 10 J = 1, P CALL CPOSL(A,LDA,N,C(1,J)) 10 CONTINUE

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

ROUTINES CALLED
CAXPY, 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)