===== Data Processing School :: Exercise CR2 =====

^ Source directory | /data/lofarschool/data/Exercise-CR1 |
^ Contact person | Andreas Horneffer, Lars Bähren |

==== Context ====

Have a look at some LOFAR TBB data.

=== Prerequisite ===

  * Some C/C++ programming.
  * Installed USG software ([[public:user software:CR-Tools]] package)
  * Successful completion of [[Exercise CR0]]

==== Description ====

Use a simple tool to generate a dynamic spectrum from LOFAR TBB data.
Track down files with high RFI.

==== Files & Directories ====

<code>
/data/lofarschool/data/Exercise-CR
|-- files.txt
|-- files_sm.txt
|-- rw_20071121
|   `-- <many data files>
|-- rw_20071122
|   `-- <many data files>
`-- rw_20071123
    `-- <many data files>
</code>

And the ''exercise_cr2'' executable.

==== Step-by-step instructions ====
  - Execute the ''exercise_cr'' programm giving a list of files as the argument. E.g.:<code>
exercise_cr2 /data/lofarschool/data/Exercise-CR/files_sm.txt
</code> or <code>
exercise_cr2 /data/lofarschool/data/Exercise-CR/files_sm.txt
</code>
  - This generates a dynamic spectrum of LOFAR data.
  - Make a local copy of the "files.txt" file and e.g. try to hunt down an event with excessive RFI. Then e.g. use the programm from ''exercise_cr1'' to plot it.



==== Example outputs ====

Executing:
<code>
exercise_cr2 /data/lofarschool/data/Exercise-CR/files_sm.txt
</code>
produces the following output on the shell and two postscript plots with the dynamic spectrum (log and linear scales):
<code>
(horneffer)lioff024> exercise_cr2 /data/lofarschool/data/Exercise-CR/files_sm.txt
Excercise-CR2 read in 50 filenames.
tbbctlIn:attachFile: Files [/data/lofarschool/data/Exercise-CR/rw_20071121/rw_20071121_011001_0100.dat] contain more than 8388608 samples! Truncating to 8388608 samples/channel!
tbbctlIn:attachFile: Files [/data/lofarschool/data/Exercise-CR/rw_20071121/rw_20071121_025501_0100.dat] contain more than 8388608 samples! Truncating to 8388608 samples/channel!
GenDynSpec: processed 50 files out of 50!
Excercise-CR2 generated Dynamic-Spectrum with shape: [1025, 50]
Elapsed: 0:42.22 - CPU: 31.601u+3.612s = 83.3%
</code>

==== Bug Reports ====

//If you are experiencing trouble getting the exercise to work, this is the place to leave a note about it.//