How to read

I have started learning ROOT and am learning things in bits and pieces. I still dont know how to find out how a particular function can be used. For example

TDecompChol

Is there a general prescription.

On the following diagram there is a chart, what does that mean ?
root.cern.ch/root/html/TDecompChol.html

How to understand so many functions described on the page mentioned.

I will be glad if someone can explain, so that I dont have to ask people how to use a particular function when I intend to use it.

Thank You

See:

  1. “A Little C++” and “CINT the C++ Interpreter” chapters in ROOT User’s Guide http://root.cern.ch/drupal/content/users-guide
  2. “Object Oriented Programming” in “C++ Language Tutorial” http://www.cplusplus.com/doc/tutorial/