Digi speed up

Speed up the calo and scent digs by a factor of ~5 by factorising the time and energy loops.

This was tested on 100 single electron events and gave identical results. This is good in that it shows the new code is working but had since the results should have slight differences due to the baseline randomisation. Turns out that the default TRandom3() sets a specific seed so the random numbers always start from the same point (WTF) and you need to call TRandom3(0) to get a random seed. This has now also been updated.

Calorimeter/CaloDigiAlgs/src/CaloWaveformDigiAlg.cxx

@@ -99,12 +99,24 @@ CaloWaveformDigiAlg::execute(const EventContext& ctx) const {
   // Create structure to store pulse for each channel
   std::map<Identifier, std::vector<uint16_t>> waveforms = m_digiTool->create_waveform_map(m_ecalID);
 
+  // Sum energy for each channel (i.e. identifier)
+  std::map<unsigned int, float> esum;  
+  for (const auto& hit : *caloHitHandle) { 
+    esum[hit.identify()] += hit.energyLoss();
+  }
+
+  // Loop over time samples
   for (const auto& tk : m_timekernel) {
     std::map<unsigned int, float> counts;    
 
     // Convolve hit energy with evaluated kernel and sum for each hit id (i.e. channel)
-    for (const auto& hit : *caloHitHandle) { 
-      counts[hit.identify()] += tk * hit.energyLoss();
+    //for (const auto& hit : *caloHitHandle) { 
+    //  counts[hit.identify()] += tk * hit.energyLoss();
+    //}
+
+    // Convolve summed energy with evaluated kernel for each hit id (i.e. channel)
+    for (const auto& e : esum) {
+      counts[e.first] = tk * e.second;
     }
 
     // Subtract count from basleine and add result to correct waveform vector