!     CalculiX - A 3-dimensional finite element program
!              Copyright (C) 1998-2021 Guido Dhondt
!
!     This program is free software; you can redistribute it and/or
!     modify it under the terms of the GNU General Public License as
!     published by the Free Software Foundation(version 2);
!     
!
!     This program is distributed in the hope that it will be useful,
!     but WITHOUT ANY WARRANTY; without even the implied warranty of 
!     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
!     GNU General Public License for more details.
!
!     You should have received a copy of the GNU General Public License
!     along with this program; if not, write to the Free Software
!     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
!
      subroutine materialdata_dvi(shcon,nshcon,imat,dvi,t1l,ntmat_,
     &  ithermal)
!
      implicit none
!
!     determines the dynamic viscosity
!
      integer imat,ntmat_,id,nshcon(*),four,ithermal
!
      real*8 t1l,shcon(0:3,ntmat_,*),dvi
!
      four=4
!     
      if(ithermal.eq.0) then
         dvi=shcon(2,1,imat)
      else
         call ident2(shcon(0,1,imat),t1l,nshcon(imat),four,id)
         if(nshcon(imat).eq.0) then
            continue
         elseif(nshcon(imat).eq.1) then
            dvi=shcon(2,1,imat)
         elseif(id.eq.0) then
            dvi=shcon(2,1,imat)
         elseif(id.eq.nshcon(imat)) then
            dvi=shcon(2,id,imat)
         else
            dvi=shcon(2,id,imat)+
     &           (shcon(2,id+1,imat)-shcon(2,id,imat))*
     &           (t1l-shcon(0,id,imat))/
     &           (shcon(0,id+1,imat)-shcon(0,id,imat))
         endif
      endif
!
      return
      end







