Notes on using the ROOT libraries in standalone C++ programs

Starting with problem sheet 6 you will need to write C++ programs that
use classes from the ROOT library, and you will also produce plots
with the program root.  To do this on linappserv1 you need to make a
small modification to your set-up.  On other computers the procedure
should be similar.

Go to your home directory and type ls -la.  You will see that you have
a file called .cshrc (it starts with a dot).  This is a file that gets
executed when you login and it sets up your environment.  You will see
in it lines of the form "setenv LESS -M" and other commands.  Using
your preferred text editor, insert in this file (e.g., below the
setenv commands) the line

source /usr/local/root/v5.20.00/slc4.gcc3.4/setup.csh

Save the file and then enter 

source .cshrc

You only have to do this once, as it will now automatically be done
every time you log in.  This defines some things needed to work with
the ROOT libraries.  

Alternatively you can simply copy the file 

/usr/local/root/v5.20.00/slc4.gcc3.4/setup.csh

to your local area and type source setup.csh whenever you want
to use the ROOT libaraies. 

For people not at RHUL, the location of the setup.csh file should be
similar -- it should work (I think) if you copy the setup.csh file
from the web page above.  Note that if you're using a shell other than
C or TC, you should use the file setup.sh (not setup.csh).

Once you have done the above, download the files from

http://www.pp.rhul.ac.uk/~cowan/stat/root/mc/

into a convenient subdirectory and build the program simpleMC by
typing gmake.  More info as well as instructions on how to produce
plots with the program root can be found in the file readme.txt in the
web area above.  More general information about root can be found at
root.cern.ch.


Glen Cowan
11 November, 2008