+ * Returns the full range of the x-axis, as determined by the most extreme
+ * values in the data set. Not affected by zooming, visibility, etc.
+ * TODO(danvk): merge w/ xAxisExtremes
+ * @return { Array<Number> } A [low, high] pair
+ * @private
+ */
+Dygraph.prototype.fullXRange_ = function() {
+ if (this.numRows() > 0) {
+ return [this.rawData_[0][0], this.rawData_[this.numRows() - 1][0]];
+ } else {
+ return [0, 1];
+ }
+};
+
+/**