var parse = this.attr_('xValueParser') || function(x) { return x; };
for (var i = 0; i < ann.length; i++) {
var a = {};
- if (!ann[i].xval && !ann[i].x) {
+ if (!ann[i].xval && ann[i].x === undefined) {
this.dygraph_.error("Annotations must have an 'x' property");
return;
}