BNSLV(3)

SYNOPSIS
SUBROUTINE BNSLV (W, NROWW, NROW, NBANDL, NBANDU, B)

NAME
bnslv - Subsidiary to BINT4 and BINTK

LIBRARY
SLATEC

TYPE
SINGLE PRECISION (BNSLV-S, DBNSLV-D)

AUTHOR
(UNKNOWN)

DESCRIPTION
BNSLV is the BANSLV routine from * A Practical Guide to Splines * by C. de Boor Companion routine to BNFAC . It returns the solution X of the linear system A*X = B in place of B , given the LU-factorization for A in the work array W from BNFAC. ***** I N P U T ****** W, NROWW,NROW,NBANDL,NBANDU.....Describe the LU-factorization of a banded matrix A of order NROW as constructed in BNFAC . For details, see BNFAC . B.....Right side of the system to be solved . ***** O U T P U T ****** B.....Contains the solution X , of order NROW . ***** M E T H O D ****** (With A = L*U, as stored in W,) the unit lower triangular system L(U*X) = B is solved for Y = U*X, and Y stored in B . Then the upper triangular system U*X = Y is solved for X . The calcul- ations are so arranged that the innermost loops stay within columns.

SEE ALSO
BINT4, BINTK

ROUTINES CALLED
(NONE)

REVISION HISTORY (YYMMDD)
800901 DATE WRITTEN
890531 Changed all specific intrinsics to generic. (WRB)
890831 Modified array declarations. (WRB)
891214 Prologue converted to Version 4.0 format. (BAB)
900328 Added TYPE section. (WRB)