anchor.diff:  !*calc_press_area:* Calculates new radii based on pressure area relnships
   
   subroutine calc_press_area(grav_type,grav_vect,KOUNT,depvar_at_node,prq_solution,&
  -    mesh_dof,ptrans,vessel_type,elasticity_parameters,pleural_density)
  +    mesh_dof,vessel_type,elasticity_parameters,mechanics_type,mechanics_parameters)
   
       use indices
       use arrays,only: dp,num_nodes,num_elems,elem_field,elem_nodes,node_xyz
       use diagnostics, only: enter_exit
       character(len=60), intent(in) :: grav_type
       character(len=60), intent(in) :: vessel_type
  +    character(len=60), intent(in) :: mechanics_type
       real(dp), intent(in) :: grav_vect(3)
       integer,intent(in) :: KOUNT,mesh_dof
       integer,intent(in) :: depvar_at_node(num_nodes,0:2,2)
       real(dp),intent(in) ::  prq_solution(mesh_dof,2)
  -    real(dp),intent(in) :: elasticity_parameters(3),ptrans,pleural_density
  +    real(dp),intent(in) :: elasticity_parameters(3),mechanics_parameters(2)
   
   !local variables
       integer :: nj,np,ne,ny,nn
  
positive.code:      elasticity_parameters(2)=0.1_dp!this is a fraction of the radius so is unitless
       elasticity_parameters(3)=0.0_dp !Not used
  else
      print *, 'Your chosen vessel type does not seem to be implemented assuming rigid'
      vessel_type='rigid'
      elasticity_parameters=0.0_dp
  endif
  
  grav_dirn=2
  
negative.code:     logical :: ADD=.FALSE.,CONVERGED=.FALSE.
      character(len=60) :: sub_name,mesh_type,vessel_type,mechanics_type,bc_type,grav_type
      integer :: grav_dirn,no,depvar,KOUNT,nz,ne,SOLVER_FLAG
      real(dp) :: MIN_ERR,N_MIN_ERR,elasticity_parameters(3),mechanics_parameters(2),grav_factor
  
      sub_name = 'evaluate_prq'
      call enter_exit(sub_name,1)
  