cd $ROOTSYS

cd tutorials/

## find tutorials for roofit:

cd roofit/

## find example for RooAddPdf

grep RooAddPdf *

##This method just give you some examples of function, you can also check https://root.cern/doc/master/index.html to get the meaning and definition of a fucniton. 在cern服务器上无法使用，04上面可以用