Uncaught TypeError in Rotating Voronoi Example

[kahunamoore]

Uncaught TypeError: Cannot read property 'x' of null

The call stack looks like this:

Uncaught TypeError: Cannot read property 'x' of null
tr @ d3.v3.min.js:2
Ze @ d3.v3.min.js:2
ar @ d3.v3.min.js:2
t @ d3.v3.min.js:4
(anonymous function) @ rotating-voronoi.js:25538
Rn @ d3.v3.min.js:1
Tn @ d3.v3.min.js:1

The minimized version of the code looks like this (in rotating-voronoi.js:25538):

strokes.timer.call(null, function() {
var pts_5281 = rotating_voronoi.get_points.call(null);
var vnoi_5282 = rotating_voronoi.vor_obj.call(null, pts_5281); // <--- ERROR IS IN THIS CALL (lineno: 25538)
rotating_voronoi.circles.attr("transform", function(p1__5280_SHARP_, p2__5279_SHARP_) {
return[cljs.core.str("translate("), cljs.core.str(cljs.core.nth.call(null, pts_5281, p2__5279_SHARP_)), cljs.core.str(")")].join("")
});
rotating_voronoi.path.attr("d", function(pt, i) {
return rotating_voronoi.line.call(null, rotating_voronoi.resample.call(null, cljs.core.nth.call(null, vnoi_5282, i)))
});
return false
});