*DECK CPROD SUBROUTINE CPROD (ND, BD, NM1, BM1, NM2, BM2, NA, AA, X, YY, M, A, + B, C, D, W, Y) C***BEGIN PROLOGUE CPROD C***SUBSIDIARY C***PURPOSE Subsidiary to BLKTRI C***LIBRARY SLATEC C***TYPE SINGLE PRECISION (CPROD-S, CPROC-C) C***AUTHOR (UNKNOWN) C***DESCRIPTION C C PROD applies a sequence of matrix operations to the vector X and C stores the result in YY. (COMPLEX case) C AA array containing scalar multipliers of the vector X. C ND,NM1,NM2 are the lengths of the arrays BD,BM1,BM2 respectively. C BD,BM1,BM2 are arrays containing roots of certain B polynomials. C NA is the length of the array AA. C X,YY The matrix operations are applied to X and the result is YY. C A,B,C are arrays which contain the tridiagonal matrix. C M is the order of the matrix. C D,W,Y are working arrays. C ISGN determines whether or not a change in sign is made. C C***SEE ALSO BLKTRI C***ROUTINES CALLED (NONE) C***REVISION HISTORY (YYMMDD) C 801001 DATE WRITTEN C 890531 Changed all specific intrinsics to generic. (WRB) C 891214 Prologue converted to Version 4.0 format. (BAB) C 900402 Added TYPE section. (WRB) C***END PROLOGUE CPROD