如何计算斜边和轴承 [英] How to compute hypotenuse and bearing
问题描述
我从@DanS下面code这个链接<一个href="http://stackoverflow.com/questions/7062115/android-how-to-display-a-map-still-image-file-with-a-moving-current-location">how-to-display-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);
}
下面是值:
- 电流:41.850033,-87.65005229999997
- upperLeft:41.866514127810355,-87.6720142364502
- lowerRight:41.83397145565242,-87.62824058532715
- mapWidth:512×512像素
下面是计算器在线位置,斜边(距离),轴承(方位角)
Here are the calculator online for Location, hypotenuse(Distance), bearing(Azimuths)
- convert LatLng to Location format(e.g. 41° 51′ 59.45″ N 87° 40′ 19.25″ W)
- compute distance & azimuths from the given Location
我得到的结果:
- 斜边= 2581
- 轴承= 135.21
- currentDistanceX = -2562
- currentPixelX = 311.9
想问问你们到:
- 以确认如果我的计算结果是正确的。
- 如何计算currentPixelY(在1分)?
- to confirm if my computed results are correct.
- on how to compute the currentPixelY (the another one point)?
顺便说一句,我打算用它来计算给定的现实生活中的位置的经纬度(电流)对我的静止图像地图,保税静止图像转化为现实生活中经纬度的upperLeft和lowerRight角落。
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.
如果你想看到的实际和放大器;预期产出,想方便地了解全貌。请参考此链接 - > <一个href="http://stackoverflow.com/questions/7072400/android-how-to-mark-the-current-location-into-a-map-still-image-source-$c$c">How标记当前位置为静止图像地图
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
推荐答案
这是实际的code我用,而不是伪code贴previously:
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
您计算出答案看起来有点假。
为了计算y变为复制所有的X标记的计算和变量使用 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()
.
这篇关于如何计算斜边和轴承的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!