subroutine plotv(v,s,sp,etot,eplas,ecreep,t,m,nn,layer,ndi,
     * nshear,jpltcd)
c
c CONTACT: ap@marc.de
c      
c* * * * * *
c
c     select a variable contour plotting (user subroutine).
c
c     v            variable
c     s (idss)     stress array
c     sp           stresses in preferred direction
c     etot         total strain (generalized)
c     eplas        total plastic strain
c     ecreep       total creep strain
c     t            current temperature
c     m            element number
c     nn           integration point number
c     layer        layer number
c     ndi (3)      number of direct stress components
c     nshear (3)   number of shear stress components
c
c* * * * * *
      implicit real*8 (a-h,o-z)                                               dp
      dimension s(1),etot(1),eplas(1),ecreep(1),sp(1)
      dimension pv(3),r(3,3)
c
c pv(1) = largest principal value
c pv(2) = intermediate principal value
c pv(3) = smallest principal value
c
c r(i,1) = direction cosines for pv(1) (i=1,2,3)
c r(i,2) = direction cosines for pv(2) (i=1,2,3)
c r(i,3) = direction cosines for pv(3) (i=1,2,3)
c
c... compute principal stresses
c input:  s,ndi,nshear,iss
c output: pv,r
      iss = 0
      call princv(pv,r,s,ndi,nshear,iss,0,0,0)
c... compute principal strains
c input:  etot,ndi,nshear,iss
c output: pv,r
      iss = 1
      call princv(pv,r,etot,ndi,nshear,iss,0,0,0)
c
      return
      end