!:NoEntropyFix:!
            DO mw=1,mwaves
              DO j=2-mbc,mx+mbc
                IF (speed(j,mw) < zero) THEN
                  Amdq(j,1:NrVars) = Amdq(j,1:NrVars) +  &
                                     speed(j,mw) * wave(j,1:NrVars,mw)
                ELSE
                  Apdq(j,1:NrVars) = Apdq(j,1:NrVars) +  &
                                     speed(j,mw) * wave(j,1:NrVars,mw)
                END IF
              END DO
            END DO
          END IF