===== Data Processing School :: Exercise CR1 =====

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

==== Context ====

This exercise demonstrates the usage of the DataReader and its ability to abstract the file format from the user. 

=== Prerequisite ===

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

==== Description ====

In this exercise you use the [[public:User Software:cr-tools:DataReader]] to open different types of files with time-series data and make some simple plots.

==== Files & Directories ====

<code>
/data/lofarschool/data/Exercise-CR
|-- 2006.02.23.04:02:50.283.event
|-- rw_20071121
|   `-- rw_20071121_000001_0100.dat
`-- rw_20080701_162002_0109.h5
</code>

And the ''exercise_cr1'' executable.



==== Step-by-step instructions ====

  - Execute the ''exercise_cr1'' executable
    * This produces some output and some plots in postscript files
  - Check in the source code how this is done.
  - Modify the source, compile it, and see what it does.
    * Check the documentation of the [[http://usg.lofar.org/doxygen/classCR_1_1DataReader.html|DataReader]] to, e.g., change the block-size, block number, or plot different data.




==== Example outputs ====

The unmodified ''exercise_cr1'' executable should produce the following output and six postscript files:
<code>
(horneffer)lioff024> ./exercise_cr1          
Loading LOPES event.                         
genOutput: Observatory: LOPES                
           Date: 1140667370                  
           Filesize: 65536                   
           plotting voltage, #xpoints:65536 #ypoints:65536
           plotting FFT, #xpoints:32769 #ypoints:32769    
Loading raw tbbctl data.                                  
genOutput: Observatory: LOFAR                             
           Date: 1195603201                               
           Filesize: 2048000                              
           plotting voltage, #xpoints:2048000 #ypoints:2048000
           plotting FFT, #xpoints:1024001 #ypoints:1024001    
Loading LOFAR hdf5 data.                                      
-- nof dipole datasets = 1
-- sample frequencies = [200]
-- Setting up DataIterator objects ...
-- Setting up header record ...
genOutput: Observatory: LOFAR
           Date: 1214929202
           Filesize: 2048000
           plotting voltage, #xpoints:2048 #ypoints:2048
           plotting FFT, #xpoints:1025 #ypoints:1025
</code>

==== Bug Reports ====

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