diff --git a/src/element.py b/src/element.py
index 816e907..87b4211 100644
--- a/src/element.py
+++ b/src/element.py
@@ -282,3 +282,16 @@ class Element_circle(Element):
     def move_along(self,delta,element):
         x=element.pos-self.pos+delta
         return x/l_2(x)*(element.size+self.size)/2+self.pos-element.pos
+
+    # for use with lattices
+    # list of lattice points covered by square
+    def lattice_points(self,lattice):
+        out=[]
+        dx=math.floor(0.5*self.size/lattice.spacing)
+        for i in range(-dx,dx+1):
+            for j in range(-dx,dx+1):
+                if i*i+j*j<=2*dx*dx:
+                    out.append(Point(self.pos.x+i*lattice.spacing,self.pos.y+j*lattice.spacing))
+        return out
+
+