Difference between revisions of "HOWTO create a ROOT tree of detector hits and display event data with the tree"
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| + | ==Getting started== | ||
The data in an evio file can be coverted into a ROOT tree by using the '''janaroot''' plugin. Suppose you want to look at the CDC hits in more detail. To do so, invoke the JANA framework using the following command line: | The data in an evio file can be coverted into a ROOT tree by using the '''janaroot''' plugin. Suppose you want to look at the CDC hits in more detail. To do so, invoke the JANA framework using the following command line: | ||
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The '''-PAUTOACTIVATE''' command-line parameter invokes the code that produces the DCDCHit object in memory. | The '''-PAUTOACTIVATE''' command-line parameter invokes the code that produces the DCDCHit object in memory. | ||
| − | To look at the janaroot.root file, run root (root janaroot.root) and at the root command line invoke the browser: | + | To look at the janaroot.root file, run root (''root janaroot.root'') and at the root command line invoke the browser (type ''TBrowser T''; this will pop up another window). |
| − | + | In the browser window, under ROOT files select janaroot.root, which gives you a list of branches on the tree. In the example below I have selected the distribution of the number of hits ''N'' in the CDC: | |
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| − | + | [[File:TBrowserView.png]] | |
| − | In the | + | |
| + | In addition to the DCDCHit data, all the raw event data types (Df250PulseIntegral, etc.) are available for perusal. | ||
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| + | ==Looking at correlations== | ||
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| + | A leaf quantity can be plotted against another leaf quantity in a given branch using the root command line interface. | ||
Revision as of 10:33, 30 September 2014
Getting started
The data in an evio file can be coverted into a ROOT tree by using the janaroot plugin. Suppose you want to look at the CDC hits in more detail. To do so, invoke the JANA framework using the following command line:
hd_ana -PPLUGINS=DAQ,TTab,janaroot file.evio -PAUTOACTIVATE=DCDCHit
The DAQ plugin converts the evio data into raw detector objects in memory. The TTab plugin applies the translation tables. The janaroot plugin fills a ROOT tree and writes it out to a file called janaroot.root in the current working directory. The -PAUTOACTIVATE command-line parameter invokes the code that produces the DCDCHit object in memory.
To look at the janaroot.root file, run root (root janaroot.root) and at the root command line invoke the browser (type TBrowser T; this will pop up another window). In the browser window, under ROOT files select janaroot.root, which gives you a list of branches on the tree. In the example below I have selected the distribution of the number of hits N in the CDC:
In addition to the DCDCHit data, all the raw event data types (Df250PulseIntegral, etc.) are available for perusal.
Looking at correlations
A leaf quantity can be plotted against another leaf quantity in a given branch using the root command line interface.
