問題描述
我在此鏈接從@DanS 獲得了以下代碼 如何顯示-a-map-still-image-file-with-a-moving-current-location
I got the below code from @DanS at this link how-to-display-a-map-still-image-file-with-a-moving-current-location
onCurrentPosition(Location current){
double hypotenuse = upperLeft.distanceTo(current);
double bearing = upperLeft.bearingTo(current);
double currentDistanceX = Math.cos(bearing) * hypotenuse;
// "percentage to mark the position"
double currentPixelX = (currentDistanceX / upperLeft.distanceTo(lowerRight) * Math.cos(upperLeft.bearingTo(lowerRight))) * mapWidth;
moveIndicatorX(currentPixelX);
}
以下是值:
- 當前:41.850033,-87.65005229999997
- 左上:41.866514127810355,-87.6720142364502
- 右下:41.83397145565242,-87.62824058532715
- 地圖寬度:512 x 512 像素
這是位置、斜邊(距離)、方位角(方位角)的在線計算器
Here are the calculator online for Location, hypotenuse(Distance), bearing(Azimuths)
- 將 LatLng 轉換為位置格式(例如 41° 51′ 59.45″ N 87° 40′ 19.25〃W)
- 計算距離&給定位置的方位角
我得到了以下結果:
- 斜邊 = 2581
- 軸承 = 135.21
- currentDistanceX = -2562
- currentPixelX = 311.9
想請大家:
- 確認我的計算結果是否正確.
- 如何計算 currentPixelY(另一點)?
順便說一句，我打算用它來計算給定現實生活 LatLng(current) 的位置，并與我的靜止圖像映射將靜止圖像的左上角和右下角結合到現實生活 LatLng 中.
By the way, I am planning to use that to compute the location of a given real life LatLng(current) against with my still image map which bonded the upperLeft and lowerRight corners of the still image into real life LatLng.
如果您想查看實際的 &預期的輸出，并希望輕松了解整個情況.請參考此鏈接-> 如何將當前位置標記為靜止圖像地圖
If you want to see the actual & expected output and want to easily understand the whole picture. Please refer to this link -> How to mark the current location into a still image map
推薦答案
這是我實際使用的代碼，不是之前貼的偽代碼:
This is the actual code I'm using, not pseudo code posted previously:
Location upperLeft = new Location("");
upperLeft.setLatitude(41.866514127810355);
upperLeft.setLongitude(-87.6720142364502);
Location lowerRight = new Location("");
lowerRight.setLatitude(41.83397145565242);
lowerRight.setLongitude(-87.62824058532715);
Location current = new Location("");
current.setLatitude(41.850033);
current.setLongitude(-87.65005229999997);
double hypotenuse = upperLeft.distanceTo(current);
double bearing = upperLeft.bearingTo(current);
double currentDistanceX = Math.cos(bearing * Math.PI / 180.0) * hypotenuse;
// "percentage to mark the position"
double totalHypotenuse = upperLeft.distanceTo(lowerRight);
double totalDistanceX = totalHypotenuse * Math.cos(upperLeft.bearingTo(lowerRight) * Math.PI / 180.0);
double currentPixelX = currentDistanceX / totalDistanceX * 512;
System.out.println(currentPixelX); // 259.3345493341548
您計算出來的答案看起來有點不對勁.要計算 Y 更改復制所有 X 標記的計算和變量以使用 Math.sin() 而不是 Math.cos().
Your calculated answer looks a bit off.
To calculate Y change copy all the X marked calculations and variables to use Math.sin() instead of Math.cos().
這篇關于如何計算斜邊和方位的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！