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authorstainer_t <thomas.stainer@oecd-nea.org>2025-09-08 13:48:49 +0200
committerstainer_t <thomas.stainer@oecd-nea.org>2025-09-08 13:48:49 +0200
commit7dfcc480ba1e19bd3232349fc733caef94034292 (patch)
tree03ee104eb8846d5cc1a981d267687a729185d3f3 /Utilib/src/ALLDLM.f
Initial commit from Polytechnique Montreal
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+*DECK ALLDLM
+ SUBROUTINE ALLDLM (L4,ASS,VEC,Z,MU1,ITY)
+*
+*-----------------------------------------------------------------------
+*
+*Purpose:
+* multiplication of a symmetric matrix in compressed diagonal storage
+* mode by a vector.
+*
+*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
+ REAL ASS(*),VEC(L4),Z(L4)
+*
+ 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=0.0
+ 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