+ // Now we remove series from seriesToAxisMap_ which are not visible. We do
+ // this last so that hiding the first series doesn't destroy the axis
+ // properties of the primary axis.
+ var seriesToAxisFiltered = {};
+ var vis = this.visibility();
+ for (var i = 1; i < labels.length; i++) {
+ var s = labels[i];
+ if (vis[i - 1]) seriesToAxisFiltered[s] = this.seriesToAxisMap_[s];
+ }
+ this.seriesToAxisMap_ = seriesToAxisFiltered;
+
+ if (valueWindow != undefined) {
+ // Restore valueWindow settings.
+ for (var index = 0; index < valueWindow.length; index++) {
+ this.axes_[index].valueWindow = valueWindow[index];
+ }
+ }
+};
+
+/**
+ * Returns the number of y-axes on the chart.
+ * @return {Number} the number of axes.
+ */
+Dygraph.prototype.numAxes = function() {
+ var last_axis = 0;
+ for (var series in this.seriesToAxisMap_) {
+ if (!this.seriesToAxisMap_.hasOwnProperty(series)) continue;
+ var idx = this.seriesToAxisMap_[series];
+ if (idx > last_axis) last_axis = idx;
+ }
+ return 1 + last_axis;
+};
+
+/**
+ * Determine the value range and tick marks for each axis.
+ * @param {Object} extremes A mapping from seriesName -> [low, high]
+ * This fills in the valueRange and ticks fields in each entry of this.axes_.
+ */
+Dygraph.prototype.computeYAxisRanges_ = function(extremes) {
+ // Build a map from axis number -> [list of series names]
+ var seriesForAxis = [];
+ for (var series in this.seriesToAxisMap_) {
+ if (!this.seriesToAxisMap_.hasOwnProperty(series)) continue;
+ var idx = this.seriesToAxisMap_[series];
+ while (seriesForAxis.length <= idx) seriesForAxis.push([]);
+ seriesForAxis[idx].push(series);
+ }
+