# Exercise 10: Writing histograms to a file 
**(10 minutes)**

In all the analysis scripts we've worked with, we've drawn any plots in
the Wrap-up section. Pick one of your scripts that creates histograms
and revise it so that it does not draw the histograms on the screen but
writes them to a file instead. Make sure that you don't try to write the
histograms to {file}`experiment.root`; write them to a different file named
{file}`analysis.root`. When you're done, open {file}`analysis.root` with the
TBrowser in command-line ROOT and check that your plots are what you
expect.

:::{hint}
In {ref}`Saving your work, part 2 <savework2>`, I described all
the commands you'll need.

Don't forget to use the ROOT web site as a reference. Here's a
question that's also a bit of a hint: What's the difference between
opening your new file with "UPDATE" access, "RECREATE" access, and
"NEW" access? Why might it be a bad idea to open a file with "NEW"
access? (A hint within a hint: what would happen if you ran your script
twice?)
:::