成交量堆叠，单独计算。

src/index.js

@@ -1005,7 +1005,7 @@ export default class StockHeatmap extends React.Component {
       // move position only if within valid range
       this.windowedData = this.data.slice(position, position + this.windowLength + 1);
 
-      if (this.windowedData.length > 200) {
+      if (this.windowedData.length > 1000) {
         this.windowedData = this.mergeWindowedData();
         this.isMerged = true;
       } else {