Implementing generic analysis methods inside detectorlib

[juanangp]

Implementing generic methods inside detectorlib after being implemented here rest-for-physics/framework#379

Summary of changes:

• TRestDetectorSignal implementing generic methods from TRestSignalAnalysis
• TRestDetectorSignal moving to std iterators rather than custom ones
• TRestDetectorSignalToHitsProcess implementing generic methods from TRestSignalAnalysis
• TRestDetectorSignalToHitsProcess added new function GetHitZCoordinate to avoid code duplication
• Removal of baseline calculation methods

[jgalan]

For me it makes no sense to have a baseline at the detector signal level. This is a stage where we have already applied data reduction. And in the best case reduced our waveforms into physical times and amplitudes.

It was kind of first approach to take all points from raw to detector signal. But we should move towards a reconstruction that reduces the data.

I understand the issue with short_t precision in rawlib, that's why I think having a std::vector <float_t> or even std::vector <double> implemented inside TRestRawSignal would solve this problem, so it this vector is not empty it means a process has filled it, and then processing will continue at float_t or double_t levels.

That way you leave also all time-signal processing routines contained within rawlib, which was one of the duties of the raw library. To compile all those codes used for time signal processing into a single entity.

[juanangp]

These functions can be indeed deleted, however I don't know if it is a good idea to define a std::vector <float_t> inside rawlib since it could be misleading. Which data is supposse to hold? Data with baseline substracted, points over threshold or smoothed data?

There are as well signal processing functions that can be used in other context, e.g. tripleMax, GausFit and many others are currently implemented inside detectorlib (actually tripleMax was duplicated inside rawlib). But in principle one could try to perform a gaussian fit to a TRestRawSignalEvent.

I believe that to make a generic class or namespace inside framework for signal analysis or processing is the way to go...