Installing Geant4

For the sake of demonstration I will assume you are installing geant4.10.00.p01 and that you 
wish to install Geant4 on your '''Desktop'''. The unzipped Geant4 package will have the 
following directory <span style="color:##00ff00> /home/your_name/Desktop/geant4.10.00.p01 </span>

In the same directory (i.e: on the '''Desktop''') create a folder called ''''Geant4-build'''
In the same directory (i.e: on the '''Desktop''') create another folder called '''Geant4-install'''

Now using the terminal as a root user, type the command:

<pre style="color: #800000; background-color: #dcdcdc">
cd /home/your_name/Desktop/Geant4-build
</pre>

This command will change your present working directory to the folder “Geant4-build”. This is important because the Terminal will use present working directory as the destination for the build files. 

Using the '''terminal''' as root user type the command:

<pre style="color: #800000; background-color: #dcdcdc">
cmake -DCMAKE_INSTALL_PREFIX = /home/your_name/Desktop/Geant4-install -DGEANT4_INSTALL_DATA=ON -DGEANT4_USE_OPENGL_X11=ON -DGEANT4_INSTALL_EXAMPLES=ON -DBUILD_SHARED_LIBS=ON -DBUILD_STATIC_LIBS=ON /home/your_name/Desktop/geant4.10.00.p01
</pre>

'''ENSURE YOU CORRECTLY TYPE THE ENTIRE PHRASE. IF YOU MISTYPE SOMETHING CERTAIN FEATURES MAY NOT WORK'''

'''Explanation'''

'''DGEANT4_INSTALL_DATA=ON''' ensures that the all of the '''optional''' modules (data files) are 
included with the installation. Failure to include these modules '''may''' prevent you from running '''certain''' simulations. It is better to include these modules; they will NOT slow your simulations 
down as they will only be called if they are needed. 

'''DGEANT4_USE_OPENGL_X11=ON''' ensures that your Geant4 installation is correctly linked to the 
visualizer '''OpenGL'''. If you do not include this command you will not be able to see the output 
of any of your simulations

'''DGEANT4_INSTALL_EXAMPLES=ON''' ensures that the example simulations included with Geant4 are insatalled

After this command has been processed you should receive the message 

<pre style="color: #800000; background-color: #dcdcdc">
-- Configuring Done
-- Generating done
-- Build files have been written to…..
</pre>

If you receive this message, type the command

<pre style="color: #800000; background-color: #dcdcdc"> 
make
</pre> 

If an error occurs during the '''“make”''' processes, retype the command '''make'''. 

This error will most likely occur if the terminal has trouble connecting to the internet. Make sure 
you have a fully functioning internet connection. It is advised to use a wired internet connection 
as some of the data files are large and will take a long time to download). 

If your internet connection is faulty (but functional) then you may have to re-type the command 
several times! Personally, I have had to retype if (on one occasion) as many as 6 times!


The '''make''' command will download the necessary extra data files and will set up the Geant4 build files in the Geant4-build directory. 

When this has been done type the command

<pre style="color: #800000; background-color: #dcdcdc">
make install
</pre>
 
to install Geant4. 


'''THE INSTALLATION PROCESS CAN TAKE SEVERAL HOURS!!'''