Digi.md

Digi stands for Digit and it represents something similar to a [[Hit]], however, instead of giving exact values, they will output currents and voltages in order to simulate the output of a real detector more closely. This class is a child class of the G4VDigi base class.

Just like hits, you can define an array of digits into a digi collection that can be used for further processing. In order to utilise digits, the user must define a [[DigitizerModule]] concrete class.

The basic header file for a digit is very similar to the [[Hit]] as it is just a container for data. Therefore, it will contain a number of getxxx() and setxxx() methods. This example will continue from the example its [[Hit]] and will record the position of the particle.

class ExampleDigi: public G4VDigi {
public:
	ExampleDigi();
	~ExampleDigi();
	
	inline void SetPosition(G4ThreeVector pos) {fpos = pos;};
	inline G4ThreeVector GetPosition() {return fpos;};

private:
	G4ThreeVector fpos;

};

typedef G4TDigiCollection<ExampleDigi> ExampleDigitsCollection;
}

In reality, the position would be represented by some copy numbers given to the [[SensitiveDetector]] that was hit by the particle, therefore, digitizing the output e.g. if you had a grid of sensitive detectors, if a particle hits the detector at (1,2), the hit would record these copy numbers, which is what the digit would extract.