SPBSL(3F)SPBSL(3F)NAMESPBSL - SPBSL solves the real symmetric positive definite band system
A*X = B using the factors computed by SPBCO or SPBFA.
SYNOPSYS
SUBROUTINE SPBSL(ABD,LDA,N,M,B)
DESCRIPTION
On Entry
ABD REAL(LDA, N)
the output from SPBCO or SPBFA.
LDA INTEGER
the leading dimension of the array ABD .
N INTEGER
the order of the matrix A .
M INTEGER
the number of diagonals above the main diagonal.
B REAL(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 SPBCO(ABD,LDA,N,RCOND,Z,INFO)
IF (RCOND is too small .OR. INFO .NE. 0) GO TO ...
DO 10 J = 1, P
CALL SPBSL(ABD,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 SAXPY,SDOT Fortran MIN0
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