Dijkstra算法 - 如何计算距离？

Question

I got the PHP class from the website : http://www.giswiki.org/wiki/Algorithmus_von_Dijkstra

In the code I see :

// $points is an array in the following format: (router1,router2,distance-between-them)
$points = array(
    array(0,1,4),
    array(0,2,I),
    array(1,2,5),
    array(1,3,5),
    array(2,3,5),
    array(3,4,5),
    array(4,5,5),
    array(4,5,5),
    array(2,10,30),
    array(2,11,40),
    array(5,19,20),
    array(10,11,20),
    array(12,13,20),
);

What is the math to get the "distance-between-them" ? I cannot figure out the math behind that.

I have WSG84 coords (GPS... example: 56.292157,-88.022461). I did the math to get the same coordinates in UTM (UTM give number X and Y, I got 4142193, 601021). I got my first and second value to populate my array. I don't know how to get the distance for the third value.

Any clues ?

Answer 1

The third value should be calculated using the Great-circle_distance algorithm. Then you can use dijkstra's algorithm.