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*DECK ALDDLM
SUBROUTINE ALDDLM (L4,ASS,VEC,Z,MU1,ITY)
*
*-----------------------------------------------------------------------
*
*Purpose:
* multiplication of a symmetric matrix in compressed diagonal storage
* mode by a vector.
* Double precision version.
*
*Copyright:
* Copyright (C) 1989 Ecole Polytechnique de Montreal
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version
*
*Author(s): A. Hebert
*
*Parameters: input
* L4 order of the coefficient matrix.
* ASS coefficient matrix in compressed diagonal storage mode.
* DIMENSION ASS(MU1(L4))
* VEC vector to multiply.
* Z vector that will be added to the result if ITY=2.
* MU1 position of each diagonal element in vector ASS.
* ITY type of multiplication (ITY=1: Z=ASS*VEC;
* ITY=2: Z=Z+(ASS-DIAG(ASS))*VEC).
*
*Parameters: output
* Z solution of the multiplication.
*
*-----------------------------------------------------------------------
*
*----
* SUBROUTINE ARGUMENTS
*----
INTEGER L4,MU1(L4),ITY
DOUBLE PRECISION ASS(*),VEC(L4),Z(L4)
*----
* LOCAL VARIABLES
*----
DOUBLE PRECISION ZK
*
GO TO (10,60),ITY
*
* CALCULATION OF Z=ASS*VEC.
10 Z(1)=ASS(MU1(1))*VEC(1)
I1=MU1(1)+1
DO 50 K=2,L4
I2=MU1(K)
KEY1=I2-K
ZK=0.0D0
DO 30 L=I1-I2+K,K-1
ZK=ZK+ASS(KEY1+L)*VEC(L)
Z(L)=Z(L)+ASS(KEY1+L)*VEC(K)
30 CONTINUE
Z(K)=ZK+ASS(KEY1+K)*VEC(K)
I1=I2+1
50 CONTINUE
RETURN
*
* CALCULATION OF Z=Z+(ASS-DIAG(ASS))*VEC.
60 I1=MU1(1)+1
DO 80 K=2,L4
I2=MU1(K)
KEY1=I2-K
DO 70 L=I1-I2+K,K-1
Z(K)=Z(K)+ASS(KEY1+L)*VEC(L)
Z(L)=Z(L)+ASS(KEY1+L)*VEC(K)
70 CONTINUE
I1=I2+1
80 CONTINUE
RETURN
END
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