Use zoomed display range when toggling y-axis. Add code comments

Author: shefalijoshi

src/plugins/plot/MctPlot.vue

@@ -642,11 +642,23 @@ export default {
 
       this.startLoading();
       const bounds = this.timeContext.getBounds();
+      let rangeBounds = {
+        start: bounds.start,
+        end: bounds.end
+      };
+      // If we have pan/zoom history, load based on the last viewed range instead of time conductor
+      if (this.plotHistory.length > 0) {
+        const historyRange = this.plotHistory.slice(-1)[0];
+        rangeBounds = {
+          start: historyRange.x.min,
+          end: historyRange.x.max
+        };
+      }
       const options = {
         size: this.$parent.$refs.plotWrapper.offsetWidth,
         domain: this.config.xAxis.get('key'),
-        start: bounds.start,
-        end: bounds.end
+        start: rangeBounds.start,
+        end: rangeBounds.end
       };
 
       series.load(options).then(this.stopLoading.bind(this));

src/plugins/plot/chart/MctChart.vue

@@ -510,13 +510,20 @@ export default {
         pointSet.reset();
       });
     },
+    // This function is designed to establish a relative coordinate system for a data series.
+    // It defines a specific data point as the new origin (0, 0).
+    // In the context of plotting large time-series data using relative time,
+    // this function is a key step in implementing the "Relative Time".
+    // It shifts the entire series so that one chosen point (offsets) now corresponds to zero on both the X and Y axes.
+    // Any subsequent data points are then plotted relative to this new origin (x - offsets.x and y - offsets.y)
     setOffset(offsetPoint, series) {
       const mainYAxisId = this.config.yAxis.get('id');
       const yAxisId = series.get('yAxisId') || mainYAxisId;
       if (this.offset[yAxisId].x && this.offset[yAxisId].y) {
         return;
       }
 
+      // Set the origin point.
       let offsets = {};
       offsets.x = series.getXVal(offsetPoint);
       offsets.y = series.getYVal(offsetPoint);