Viewing the Changing Histograms

In order to view the histograms created by QOD, the Physics Analysis Workstation (PAW) package is used. Within PAW the use of a global memory section allows one to access the histograms being made by QOD. From PAW a macro (or kumac) is run which pulls up the Changing, Reference, and Total histograms for each Sample histogram which was significantly different in the short term, or the Sample and Total histograms for long term changes (see Running QOD   ). By viewing changes through various histograms the user is able to recognize their source and make appropriate adjustments.

After viewing the changing histograms one may wish to return to a certain set for a second look. This is accomplished by running a PAW macro (see Viewing Specific Sets of Histograms   ). Sometimes, the component of the experiment which has caused a change cannot be modified during the current run. In this case it is useful to ignore the resultant error messages caused by this change. A program is available allowing the user to turn off the changing histogram messages for specific plots (see Disabling Histogram Monitoring   ). The monitored parameters and details for interpreting their changes will be discussed in the next chapter.