Robust interpolation for ShortleyWeller

for particles "on" the border of the chamber.

Author: elebelli

interp_field_for_with_border.f

@@ -88,9 +88,14 @@ subroutine int_field_border(N_mp,xn,yn, bias_x,bias_y, dx,dy,
             Ey_n(p) = Ey_n(p) + efy((i+1),(j+1))*wei_i1j1;
 
             if (anyexternal .eqv. .true.) then
+		if ((wei_ij+wei_i1j+wei_ij1+wei_i1j1)>0.) then
                 fact_correct = 1./(wei_ij+wei_i1j+wei_ij1+wei_i1j1)
                 Ex_n(p) = Ex_n(p)*fact_correct
                 Ey_n(p) = Ey_n(p)*fact_correct
+		else
+		Ex_n(p) = 0.
+                Ey_n(p) = 0.
+		end if
             end if
 
         end if