1. Please unzip the tutorial.tar

2. In the folder, you will get 3 *.C files. Please upload these 3 files onto DiCOS.

On the data management, you can copy it, edit it, and delete it.

3. Generate data.

a) In the file generate.C, 2 random number generator is defined. You can get 10k of random number of X and Y value if you run this file one time. This code will save the results in the "output.root".

b) Here, with the advantage of using DiCOS, we can generate 100 times of this code in parallel which means 1 million. Follow the steps the picture showed below.

c) After submitted, DiCOS will automatically distribute computing resources and you can check the job status in job monitor page.

Those output.root files will transmit utomatically to folder Output/rootgen/

So far, we have got the 100 *output.root using DiCOS. Pretty cool to use DiCOS for the parallel computing right?

How to analysis current data? (100 *.root files)

1. Pretty much like previous steps. All you need to change is the input files, choose the whole folder of Output/rootgen/ as input data. No of jobs set as one. Then you can get your plots when computing is finished.

2. Get your plots back to your PC! After the jobs are finished.

Let’s check what we get…

Feeling great? Let’ try another example.

If you want to get your output as jpg, gif etc., you can read example.C carefully. It is not that hard to understand.

Please do this yourself, submit example.C with the same procedure before. Please do not chose any input data and set Num of jobs to be 1.

You will get the pretty awesome color wheel below.

Example file

tutorial.tar.txt (After downloading, remember to remove the ".txt" behind file name)

To get more about root, please check:

https://root.cern.ch/drupal/content/root--‐users--‐guide--‐600
https://root.cern.ch/root/htmldoc/tutorials/hist/index.html
https://root.cern.ch/root/htmldoc/tutorials/graphs/index.html
https://root.cern.ch/root/htmldoc/tutorials/graphics/index.html