so you'd have to calculate the increment gained each time the GPS collects data (say, every 30 seconds, or so?), and add up the result:
delta_x = horizontal distance
delta_z = vertical distance
pathlength += Sqrt[ delta_x^2 + delta_z^2 ]
That's what we're doing with this script. In the first instance of the "while" loop we get the difference from the values in lines 1 and 2. In the next instance we use lines 2 and 3, and so on until we've processed all the lines in the data record.
Okay, I already have the value for delta_z in the $difference variable .
I can get the value for delta_x easy enough, but I've going to need some help with the pathlength math. That's all a foreign language to me. After I get the delta_x value if you all can help me break it down so I can convert it to perl code we'll have the results we're looking for.
After that I can convert this code into a "Web App" that you can upload your track file to and get the results.