your working place:

# cd /home/ceres/minjung/nora

if you want to edit the code.

# emacs coincidence_rate1.C & 

then, you will see text editor.
in the text editor, on top of your editor, you will see
how you save file and quit. 

once you finish modifying code, run root

# root coincidence_rate1.C

for exiting root session, type .q and enter.
then, you will get plot name below. 

coincidence_rate2.gif

to see files under your directory, type:

# ll

for copy file:
#cp coincidence_rate1.gif ~/public_html/www/trd/

then, you can find the file under:
https://www.physi.uni-heidelberg.de/~minjung/www/trd/