Event display for LArPix.
Clone or download this repository. It includes all of the library files and dependencies, so long as you have a WebGL-enabled browser, such as any modern version of Chrome, Firefox, Safari, etc. You can verify WebGL works on your browser here.
Once the repository is downloaded, you must make sure all the files have
the appropriate permissions, namely world-readable. There is a helper
script, set_permissions.sh which you can use to set the permissions
for most of the files. It just has a list of files, though, and doesn't
do anything fancy. So, particularly for your own data files and geometry
files, you'll have to update those permissions yourself using
chmod a+r data/file1.json data/file2.json .... Also, all the directories
must be made world-examinable using the helper script or chmod a+x folder.
Lastly, every time a file is updated by git, the permissions are reset. So if
there is a problem after an update, first make sure all the files have the
correct permissions.
This event loads LArPix Event HDF5 files, createable from a LArPix+HDF5 file using the scripts here (TODO: add link).
The data files should be stored in the static/data directory. In addition,
a new file called fileList.json must be manually added to the
data directory. This file contains a listing of all the data files
and also associates a geometry file to each data file. An example
fileList.json file is located at data/fileList.json.example.
The geometry files must be copied from LArPix Geometry and renamed to
have a .txt extension.
Run python app.py (optionally specify a port other than 5000 using
e.g. -p 5001.
Navigate in your browser to localhost:5000 (or whatever custom port you used).
Select a data file to load using the drop-down menu at the top right.
Navigate by left-clicking and dragging to rotate, right-clicking and dragging pan, and scrolling to zoom in and out.
Hits will load such that the earliest hit on screen is at z = 0, i.e. at
the pixel plane. This is because we have no t0.
The legend will display basic information about the event. In addition, if any hits are not currently visible on the screen, a red warning will appear.
The URL will automatically update every time you load new hits. This way, you can save the URLs for important events, share them, etc.
The terms hits and packets are used interchangeably.
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Hit index The sequential packet number of the earliest hit displayed on screen. Resets to 0 for each new file.
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Next cluster Search and load the next cluster. A cluster is defined as a certain number of hits within a certain time window. In the Details drop-down, you can configure the multiplicity cut and time window using "Multiplicity cut" and "Time cut". Adjust the "Hits displayed" value to change the number of hits actually displayed, e.g. if you want to show more hits or fewer hits than required by the multiplicity cut.
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Next anticluster Search and load the next anticluster. An anticluster is defined as all the hits between two quiet periods, subject to a multiplicity cut. For example:
Time -------------->
[ x x x x x x x x x x x x x x x x ]
<--Anticluster 1--> <Anticluster 2> <Anticluster 3>
<---dt----> <----dt---->
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Reset camera Bring the camera back to the original zoom, pan, and rotation so that the pixel plane is centered and parallel to the screen.
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Data file Pick the data file to view from the drop-down menu.
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Details > Hits displayed The number of hits which are loaded onto the display. If not all of them are actually displayed on the screen (because of the camera's perspective) then a warning will appear below the legend in the bottom left of the screen. Note that for clusters, this value is an input to the display, while for anticlusters, it is an output.
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Details > Multiplicity cut The minimum number of hits required for either a cluster or an anticluster.
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Details > Time cut The time interval used for identifying clusters and anticlusters.
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Details > Z scale Controls the Z scale (time coordinate), where a larger Z scale means the points appear closer together. For an accurate conversion between Z (position) and time, the Z scale should be set to 1/(drift speed) in units of ns/mm. The orange ruler for the Z axis will adjust in length as the Z scale is adjusted.
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Details > min/max_index The range of the "Hit index" slider. These fields are automatically adjusted by both "Next" buttons so that it is easy to slide a little bit forward and backward. You can also manually adjust these sliders, but they will be reset the next time you click either "Next" button.
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Colors > shading Turn on/off the shading/shadow effects for the hit objects. The shading helps with the 3d effect, but it can make colors. like yellow and orange look similar. Turn off shading when the color scale interpretation is critical.