SLATEC Routines --- CPRODP ---

*DECK CPRODP
      SUBROUTINE CPRODP (ND, BD, NM1, BM1, NM2, BM2, NA, AA, X, YY, M,
     +   A, B, C, D, U, Y)
C***BEGIN PROLOGUE  CPRODP
C***SUBSIDIARY
C***PURPOSE  Subsidiary to BLKTRI
C***LIBRARY   SLATEC
C***TYPE      SINGLE PRECISION (CPRODP-S, CPROCP-C)
C***AUTHOR  (UNKNOWN)
C***DESCRIPTION
C
C PRODP applies a sequence of matrix operations to the vector X and
C stores the result in YY. (Periodic boundary conditions and COMPLEX
C case)
C
C BD,BM1,BM2     are arrays containing roots of certain B polynomials.
C ND,NM1,NM2     are the lengths of the arrays BD,BM1,BM2 respectively.
C AA             Array containing scalar multipliers of the vector X.
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,U,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  CPRODP