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Error Handling

The MAPGEN program checks for errors from the user and from I/O operations. Errors detected are reported on the terminal and the program may abort depending on the condition after writing an appropriate message.

The program first checks for errors that occur during the input phase and do not require access to the data. Typical errors are: invalid options, invalid dates and times, values out of range and so forth. These errors are flagged with a short explanatory message and the user is requested to correct them. The user may also safely cancel the execution at any time during the input phase by clicking on the Quit menu option.

Other input errors such as incompatible sky limits have to be checked after the input step is completed. The program also verifies that the bin size selected by the user does not generate a number of bins on any axis that exceeds 360 on the X axis and 180 on the Y axis. In addition the total number of bins (all energy levels) may not exceed 648000. For rectangular plots, the program forces the number of bins on both axis to be even numbers by removing the last bin and writing a warning message if necessary.

If no data is found within the user time range, the error is reported after checking the catalog. In the case where no data meets the other selection criteria, the program must first read all the input files before detecting and reporting the problem. In all of these cases, an explanatory message is written and the program terminates with a non zero return code.

Errors will occur either in the input phase or while the program is running if the environment variables do not point to the correct directories. Other errors will be generated if the SMDB or SELECT files are not in the correct format. If these files are brought over from the IBM mainframe, they must be converted to Sun format with the /analysis/data/smdb/TOOLS/convsmdb and /analysis/data/select/TOOLS/convselect programs. Errors in opening and reading files will be generally flagged by system messages.


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Next: About this document ... Up: No Title Previous: Outputs
CGRO SSC
1998-06-29