installation.md

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+# Installation
+These instructions assume that your operating system is [Ubuntu](http://www.ubuntu.com/).
+
+## 1. Install ROOT
+This is most easily accomplished with the command: `sudo apt-get install root-system`
+
+## 2. Install GEANT4
+Follow the [official installation instructions](http://geant4.web.cern.ch/geant4/support/gettingstarted.shtml).
+
+## 3. Install VeikonKone
+
+1. Install ``git``
+   It is most likely already installed. Run `git --version` to check. If it is not installed, run `sudo apt-get install git cmake`
+
+2. Get CMake: `sudo apt-get install cmake`
+
+3. Add your ssh key to you gitlab profile  
+   1. (if you already have a ssh key skip this)  
+     `ssh-keygen -t rsa -C "<your_email>"`
+   2. Copy the output from   
+     `cat ~/.ssh/id_rsa.pub`
+   3. Insert it here  
+     https://git.kern.phys.au.dk/profile/keys
+
+4. In the parent directory to where you want AUSAlib  
+   `git clone git@git.kern.phys.au.dk:ausa/ausalib.git`
+5. cd into ausalib  
+   `cd ausalib`
+6. switch to latest stable edition  
+   `git checkout stable`
+7. Build a makefile for AUSAlib  
+   `cmake ./`
+8. Build AUSAlib.   
+   `make -j 4`  
+    You will now have a libAUSA.a
+9. You install AUSAlib two ways 
+    * __System wide install:__ If you want the headers copied to `/usr/local/include` and the library to `/usr/local/lib` i.e. where to compiler normally looks for this `sudo make install`  
+    * __Local install:__ Here you must define the two environment variables `AUSALIB_INC_DIR` the AUSAlib include directory and `AUSALIB_LIB_DIR` to the location of `libAUSA.a`. A convenient way to do this is to add the following lines to you `~/.bashrc` or `~/.profile`
+```
+    export AUSALIB_INC_DIR=<path to ausalib>/ausalib/include
+    export AUSALIB_LIB_DIR=<path to ausalib>/ausalib/build
+```
+__OSX__: OSX users should add it to `~/.profile` and NOT to `~/.bashrc`
+10. Export the resource directory environment variable, `AUSALIB_RES_DIR`. This can also conveniently be added to `~/.bashrc` or `~/.profile`:
+    ```export AUSALIB_RES_DIR=<path to ausalib>/ausalib/res```
+
+**OBS: When you pull AUSAlib remember to cmake ./**
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