php - 如何最好地计算两个城市(加拿大)之间的距离？

Question

我有一个客户要我计算城市之间的距离(以英里为单位)。我正在用 PHP、javascript 做项目，我一直在阅读一些 long/lat 数据库，但仍然无法找到从哪里开始以及如何使用它。有没有我可以通过传递两个城市名称来查询的网络服务，它可以返回以英里或公里为单位的距离？请帮忙

Answer 1

http://code.google.com/apis/maps/documentation/javascript/geometry.html#Distance

Distance and Area FunctionsThe distance between two points is the length of the shortest path between them. This shortest path is called a geodesic. On a sphere all geodesics are segments of a great circle. To compute this distance, call computeDistanceBetween(), passing it two LatLng objects.

You may instead use computeLength() to calculate the length of a given path if you have several locations.

To compute the area of polygonal area, call computeArea(), passing the array of LatLng objects defining a closed loop.

如果您不想维护一个 GEO 数据库来维护某个地方/城市的纬度/经度，那么您还可以使用 Google API 检索“地址”的坐标: http://code.google.com/apis/maps/documentation/javascript/services.html#GeocodingRequests

如果您不是谷歌粉丝，另一种选择是使用在 Javascript 中实现的大圆计算器的变体:

https://gist.github.com/missinglink/ab7c8b9b8699622539986373e6237fd4

https://www.edwilliams.org/gccalc.htm