*DECK BNSLV SUBROUTINE BNSLV (W, NROWW, NROW, NBANDL, NBANDU, B) C***BEGIN PROLOGUE BNSLV C***SUBSIDIARY C***PURPOSE Subsidiary to BINT4 and BINTK C***LIBRARY SLATEC C***TYPE SINGLE PRECISION (BNSLV-S, DBNSLV-D) C***AUTHOR (UNKNOWN) C***DESCRIPTION C C BNSLV is the BANSLV routine from C * A Practical Guide to Splines * by C. de Boor C C Companion routine to BNFAC . It returns the solution X of the C linear system A*X = B in place of B , given the LU-factorization C for A in the work array W from BNFAC. C C ***** I N P U T ****** C W, NROWW,NROW,NBANDL,NBANDU.....Describe the LU-factorization of a C banded matrix A of order NROW as constructed in BNFAC . C For details, see BNFAC . C B.....Right side of the system to be solved . C C ***** O U T P U T ****** C B.....Contains the solution X , of order NROW . C C ***** M E T H O D ****** C (With A = L*U, as stored in W,) the unit lower triangular system C L(U*X) = B is solved for Y = U*X, and Y stored in B . Then the C upper triangular system U*X = Y is solved for X . The calcul- C ations are so arranged that the innermost loops stay within columns. C C***SEE ALSO BINT4, BINTK C***ROUTINES CALLED (NONE) C***REVISION HISTORY (YYMMDD) C 800901 DATE WRITTEN C 890531 Changed all specific intrinsics to generic. (WRB) C 890831 Modified array declarations. (WRB) C 891214 Prologue converted to Version 4.0 format. (BAB) C 900328 Added TYPE section. (WRB) C***END PROLOGUE BNSLV