1 files changed, 21 insertions, 8 deletions
diff --git a/src/EHFinder_FindSurface.F90 b/src/EHFinder_FindSurface.F90
index bbd9521..221d969 100644
--- a/src/EHFinder_FindSurface.F90
+++ b/src/EHFinder_FindSurface.F90
@@ -21,6 +21,10 @@ subroutine EHFinder_FindSurface(CCTK_ARGUMENTS)
   CCTK_INT :: interp_handle2
 
   character(len=30) :: info_message
+  character(len=200) :: surface_interp
+  CCTK_INT :: surface_interp_len
+  character(len=7) :: surface_order
+
   CCTK_INT, dimension(4) :: bbox
   CCTK_INT, dimension(2) :: gsh, lsh, lbnd, ubnd, nghost, maxl
 
@@ -398,18 +402,27 @@ subroutine EHFinder_FindSurface(CCTK_ARGUMENTS)
   rsurf = zero
   n_since_last_reduction = -1
 
-  ! Get and interpolation handle for Hermite polynomial interpolation. This
-  ! is used to avoid problems with non-continuous derivatives in the Newton
-  ! iteration later on.
-!  call CCTK_InterpHandle ( interp_handle, "Lagrange polynomial interpolation" )
-  call CCTK_InterpHandle ( interp_handle, "Hermite polynomial interpolation" )
+  ! Get and interpolation handle for required polynomial interpolation.
+  ! If Lagrange polynomial interpolation does not work try Hermite
+  ! polynomial interpolation, which avoids problems with non-continuous
+  !  derivatives in the Newton iteration later on.
+
+  ! First convert the string parameter to a Fortran string.
+  call CCTK_FortranString ( surface_interp_len, surface_interpolator, &
+                                                surface_interp )
+
+  ! Then get the hande ...
+  call CCTK_InterpHandle ( interp_handle, surface_interp(1:surface_interp_len) )
+
   if ( interp_handle .lt. 0 ) then
     call CCTK_WARN( 0, "Cannot get handle for interpolation. Forgot to activate an implementation providing interpolation operators??" )
   end if
 
-  ! For now order=2 is hard wired.
-!  call Util_TableCreateFromString ( table_handle, "order=3" )
-  call Util_TableCreateFromString ( table_handle, "order=2" )
+  ! Write the required interpolation order parameter into a fortran string.
+  write(surface_order,'(a6,i1)') 'order=',surface_interpolation_order
+
+  ! Then create a table from the string.
+  call Util_TableCreateFromString ( table_handle, surface_order )
   if ( table_handle .lt. 0 ) then
     call CCTK_WARN( 0, "Cannot create parameter table for interpolator" )
   end if