FT0 EventsPerBc calibration: storing histograms in float format, updated readme

Author: wpierozak

Detectors/FIT/FT0/calibration/README.md

@@ -19,6 +19,13 @@ Generates histograms of **Events per Bunch Crossing (BC)**. Events can be filter
 ## How to Run
 
 ### Simulation Data
+First, it is important to digitize data with a non-zero run number, orbit, and timestamp. To set these parameters, one can use the `--configKeyValues` option, as shown in the example below.
+```
+o2-sim-digitizer-workflow \
+--onlyDet FT0 \
+--configKeyValues="HBFUtils.nHBFPerTF=128;HBFUtils.orbitFirst=128;HBFUtils.orbitFirstSampled=256;HBFUtils.runNumber=560560;HBFUtils.timestamp=1768464099000"
+```
+
 To process simulation data, digits must first be converted to RAW format. The `o2-ft0-digi2raw` tool performs this conversion and generates the required configuration file.
 
 Once converted, you can run the calibration either as a single integrated workflow or by spawning as the sender and receiver components separately.

Detectors/FIT/FT0/calibration/include/FT0Calibration/EventsPerBcCalibrator.h

@@ -30,7 +30,7 @@ namespace o2::ft0
       const int32_t mMinAmplitudeSideA;
       const int32_t mMinAmplitudeSideC;
 
-      std::array<double, o2::constants::lhc::LHCMaxBunches> mTvx{0.0};
+      std::array<float, o2::constants::lhc::LHCMaxBunches> mTvx{0.0};
       size_t entries{0};
       long startTimeStamp{0};
       long stopTimeStamp{0};

Detectors/FIT/FT0/calibration/src/EventsPerBcCalibrator.cxx

@@ -12,14 +12,14 @@ namespace o2::ft0
     {
         size_t oldEntries = entries;
         for(const auto& digit: data) {
-            double isVertex = digit.mTriggers.getVertex();
+            float isVertex = digit.mTriggers.getVertex();
             if (digit.mTriggers.getAmplA() < mMinAmplitudeSideA || digit.mTriggers.getAmplC() < mMinAmplitudeSideC) {
               continue;
             }
             mTvx[digit.mIntRecord.bc] += isVertex;
             entries += isVertex;
         }
-        LOG(debug) << "Container is filled with " << entries - oldEntries << " new VTX events";
+        LOG(debug) << "Container is filled with " << entries - oldEntries << " new events";
     }
 
     void EventsPerBc::merge(const EventsPerBc* prev)