Particle Simulation Parser (PSP)

PSP organizes the simulation data for part II of the Elementary Particles Experiment (TAU). This is an extension of the ParticleSimulation (Python) project by @elaav. PSP processes the output of injects.py and organizes the events into an array in a logical manner.

Getting Started

Although PSP only needs the simulation output file it is recommended to use it in conjunction with the ParticleSimulation script (which should be installed on the TAU server).

Prerequisites

• XAMPP or any other Apache Distribution in order to execute the PHP scripts on your computer

• (Optional) PhpSpreadsheet library for producing Excel spreadsheet

Configuring the script

If you chose to install the PhpSpreadsheet library you must specify the Composer directory in config.php. It usually looks like C:/Users/<USER_NAME>/vendor/autoload.php in Windows.

Using the script

By default, the simulation output (.txt file) must be placed in the root directory (i.e. the same directory as parser.php), but you can change this setting (SIM_OUTPUT_FILE_PATH) in config.php.

The method Event::getEvents() (located in lib/event.php) constitutes the core of the parser. It scans the events from the output text file and organizes them in an array of Event objects. Each such object has the following structure:

Code Snippet

Event Object
(
	[injection_momentum] => 8.0 // Value of the initial momentum (in this example 8.0)
	[spectrometer_data] => Array // Stores the spectrometer data (empty if there's no data)
		(
			[track_data] => Array
				(
					[1] => Array // The index corresponds to the track number (here it means Track No. 1)
						(
							[curvature] => Array
								(
									[value] => -0.130972825E-02
									[error] => 0.10885E-09
								)

							[tandip] => Array
								(
									[value] => 0.099900089
									[error] => 0.22033E-03
								)

						)

					[2] => Array
						(
							[curvature] => Array
								(
									[value] => ...
									[error] => ...
								)

							[tandip] => Array
								(
									[value] => ...
									[error] => ...
								)

						)
			.
			.
			.
				)

			[vertices_data] => Array
				(
					[0] => Array
						(
							[tracks] => Array // Always contains 2 elements - the two tracks corresponding to this vertex
								(
									[0] => 1
									[1] => 2
								)

							[data] => Array
								(
									[coordinates] => Array
										(
											[x] => Array
												(
													[value] => 81.17825
													[error] => 24.59993
												)

											[y] => Array
												(
													[value] => -6.81394
													[error] => 4.69129
												)

											[z] => Array
												(
													[value] => 8.87917
													[error] => 1.97983
												)

										)

									[angle] => Array
										(
											[value] => 0.00072
											[error] => 0.09287
										)

								)

						)
			.
			.
			.
				)

		)

	[cluster_number] => 1 // The number of clusters in the calorimeter
	[cluster_data] => Array // Array with cluster data
		(
			[0] => Array
				(
					[pulse_height] => 23.0
					[x] => 133.0
					[y] => -23.0
					[z] => 16.0
				)

		)

	[has_charged_products] => Boolean // TRUE if charged particles were produced, FALSE otherwise
	[has_muon_hits] => Boolean // Self-explanatory
	[number_of_tracks] => 3 // Self-explanatory
	[number_of_vertices] => 3 // Self-explanatory
)

We perform the loading and the filtering of events in parser.php. In essence, that's the only file you need to work with.

Important note: if you prefer .txt output over .xlsx use plain_parser.php instead (no need to install PhpSpreadsheet in this case)

Results are saved to results/parsed_output(.xlsx/.txt) by default, but you can modify the path and the file name in config.php.

Classes & Methods

Table (.xlsx)

• $table = new Table(<table_column_labels>, <table_position>) creates a new Table object and loads it to the variable $table. The first argument to the object constructor is <table_column_labels> - an array of strings containing the column labels (e.g. ['First column', 'Second column', ...]). The second argument is <table_position> - a string which has the format of an Excel spreadsheet cell and specifies where the table should be put (by default it is set to A1, i.e. the first column label will be placed there)

• $table->addTableRow(<value>) adds a row to the previous $table. The argument <value> is an array which should have the same order as the column labels. In other words, <value> should have the following form ['First cell value', 'Second cell value', ...]

• $table->createHeader(<title>, <range>, <data>) creates a header with specified title (<title>) and data provided by an array (<data>). Range is a string of the form 'J2:Q' (default value) and it specifies where the header should be placed and how wide it should be (the height is adjusted automatically, which is why Q in this example is not followed by a number). The last argument is <data> - an array of the format ['Property' => ['value' => <some_value>, 'unit' => <some_unit>], 'Unitless Property' => <some_value>, ...]. For instance, the code

  $table->createHeader('Pion', 'A1:H', [
    	'Momentum' => ['value' => 10, 'unit' => 'GeV'], 
    	'Total number of injections' => 1234, 
    	'Number of times that a pion decayed into two photons' => 678
  ]);

  produces the following result (notice the box starts at A1 and ends on column H, as expected):