Fix curve-pot example [ci skip]

examples/curve-pot.py

@@ -161,6 +161,7 @@ def draw_pot_figure(aspect_ratio,
             evt, (y,) = lpot(queue, native_curve.pos, ovsmp_curve.pos,
                     centers,
                     [xovsmp * ovsmp_curve.speed * ovsmp_weights],
+                    expansion_radii=np.ones(centers.shape[1]),
                     **lpot_kwargs)
 
             return y
@@ -185,6 +186,7 @@ def draw_pot_figure(aspect_ratio,
     evt, (curve_pot,) = lpot(queue, native_curve.pos, ovsmp_curve.pos,
             centers,
             [ovsmp_density * ovsmp_curve.speed * ovsmp_weights],
+            expansion_radii=np.ones(centers.shape[1]),
             **lpot_kwargs)
 
     # }}}
@@ -263,7 +265,7 @@ def draw_pot_figure(aspect_ratio,
 
 
 if __name__ == "__main__":
-    draw_pot_figure(aspect_ratio=1, nsrc=100, novsmp=100, helmholtz_k=(15+4j)*0.3,
+    draw_pot_figure(aspect_ratio=1, nsrc=100, novsmp=100, helmholtz_k=(35+4j)*0.3,
             what_operator="D", what_operator_lpot="D", force_center_side=1)
 
 #    pt.savefig("eigvals-ext-nsrc100-novsmp100.pdf")