如何計算斜邊和軸承

Question

我從@DanS下面的代碼，在此鏈接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); 
} 

這裏是值：

• 電流：41.850033，-87.65005229999997
• upperLeft： 41.866514127810355，-87.6720142364502
• lowerRight：41.83397145565242，-87.62824058532715
• mapWidth：512×512像素

這裏有計算器在線位置，斜邊（距離），軸承（方位角）

• convert LatLng to Location format(e.g. 41° 51′ 59.45″ N 87° 40′ 19.25″ W)
• compute distance & azimuths from the given Location

我得到了結果：

• hyp otenuse = 2581
• 軸承= 135.21
• currentDistanceX = -2562
• currentPixelX = 311.9

想問一下你們到：

1. 確認，如果我的計算結果正確。
2. 關於如何計算currentPixelY（另一個點）？

順便說一句，我打算用它來計算給定現實生活中的位置，經緯度（電流）對與粘接靜止圖像的upperLeft和lowerRight角落到現實生活中我的靜態圖像地圖經緯度。

如果你想看到實際的&預期輸出，並且想要輕鬆理解整個圖片。請參考此鏈接 - >How to mark the current location into a still image map

Answer 1

這是我用實際的代碼，而不是僞代碼以前發佈的：

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 

你的答案計算看起來有點假。 要計算Y更改，請複製使用Math.sin()而不是Math.cos()的所有X標記的計算和變量。