DPOSL(3F)DPOSL(3F)NAMEDPOSL - DPOSL solves the double precision symmetric positive definite
system A * X = B using the factors computed by DPOCO or DPOFA.
SYNOPSYS
SUBROUTINE DPOSL(A,LDA,N,B)
DESCRIPTION
On Entry
A DOUBLE PRECISION(LDA, N)
the output from DPOCO or DPOFA.
LDA INTEGER
the leading dimension of the array A .
N INTEGER
the order of the matrix A .
B DOUBLE PRECISION(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 DPOCO(A,LDA,N,RCOND,Z,INFO)
IF (RCOND is too small .OR. INFO .NE. 0) GO TO ...
DO 10 J = 1, P
CALL DPOSL(A,LDA,N,C(1,J)) 10 CONTINUE LINPACK. This version dated
08/14/78 . Cleve Moler, University of New Mexico, Argonne National Lab.
Subroutines and Functions BLAS DAXPY,DDOT
Page 1