函數 createHeatMap

createHeatMap(
    terrainView: TerrainView,
    sensorThings: SensorThingsResource,
    setting: DrawSetting,
    onProgress: (progressRate: number) => void,
    onCompleted: (overlay: null | TerrainVisualizedDataGridOverlay) => void,
): void
用SensorThings資料建立熱圖圖層。
參數
- terrainView: TerrainView
  圖台手柄。
- sensorThings: SensorThingsResource
  SensorThings資料。
- setting: DrawSetting
  作畫設定參數。
- onProgress: (progressRate: number) => void
  處理進度的回呼，傳回取資料的進度。
- onCompleted: (overlay: null | TerrainVisualizedDataGridOverlay) => void
  處理完成的回呼，傳回熱圖圖層。
回傳 void
範例
```
let drawSetting = new ov.SensorThings.PM25DrawSetting();
let overlay = null;
ov.SensorThings.createHeatMap(terrainView, resource, drawSetting, console.log, function(layer){ overlay = layer; });
```
- 定義於 src/common/sensorThings/PilotGaea-SensorThings.ts:180