graphhopper/graphhopper — pull request #169 by karussell (2014-03-18 16:14:43+00:00)
Title: Possibility to take elevation data into account

This pull request adds elevation data to GraphHopper. Please have a look and report back any issues you get or you see!

Several things were necessary to do so:

* several data structure needed an elevation property
* the import process needs to import elevation data, we currently use SRTM but others like CGIAR will follow
* If a special FlagEncoder is used there are two speed values (up and down hill). Useful for traffic jams too. This is already merged to master. See Bike2FlagEncoder for an example.
* The UI now displays the elevation nicely per route if imported, see below

The master branch already has cherry picked some changes from this:
* the introduced reverse property in e.g. the Weighting.calcWeight method
* the algorithms now have a notion of two weights per edge
* CH is working for two weights per edge

There are still some things to do:
* speed up of several things
* the web API should be moved to #164 in order to avoid "clear text" coordinates for instructions which is especially bad for biking & hiking tours
* trying out world wide coverage and preparation
* currently not possible to use elevation only for speed changes and throw away after import

![ele-screenshot](https://f.cloud.github.com/assets/129644/2450114/4b10626e-aeb8-11e3-8db0-810884318d23.png)