Fix for FE_OVERFLOW in PHOS

shahor02 · shahor02 · commit 301f42a964ea · 2023-08-22T17:26:58.000+02:00
2 problems: (1)if the chi2 is too large, its implicit conversion to float leads to overflow
(2) in my FST run the getChi2 was called before it was assigned in the fit, and since it was
not initialized in the fitter c-tor, it returned a random huge value. Initialization helps
to avoid random value but one should avoid querying getChi2 w/o fit.
diff --git a/Detectors/PHOS/reconstruction/include/PHOSReconstruction/CaloRawFitter.h b/Detectors/PHOS/reconstruction/include/PHOSReconstruction/CaloRawFitter.h
@@ -97,8 +97,8 @@ class CaloRawFitter
   FitStatus mStatus = kNotEvaluated; ///< status of last evaluated sample: -1: not yet evaluated; 0: OK; 1: overflow; 2: too large RMS; 3: single spikes
   short mMaxSample = 0;              ///< maximal sample
   float mAmp;                        ///< amplitude of last processed sample
-  float mTime;                       ///< time of last processed sample
-  float mChi2;                       ///< chi2 calculated in last fit
+  float mTime = 0;                   ///< time of last processed sample
+  float mChi2 = 1e10;                ///< chi2 calculated in last fit
   short mSpikeThreshold;
   short mBaseLine;
   short mPreSamples;
diff --git a/Detectors/PHOS/reconstruction/src/AltroDecoder.cxx b/Detectors/PHOS/reconstruction/src/AltroDecoder.cxx
@@ -9,14 +9,14 @@
 // granted to it by virtue of its status as an Intergovernmental Organization
 // or submit itself to any jurisdiction.
 #include <cstring>
+#include <cstdint>
 #include <boost/format.hpp>
 #include "InfoLogger/InfoLogger.hxx"
 #include "PHOSBase/PHOSSimParams.h"
 #include "PHOSBase/Geometry.h"
 #include "PHOSReconstruction/AltroDecoder.h"
 #include "PHOSReconstruction/RawReaderMemory.h"
 #include "PHOSReconstruction/RawDecodingError.h"
-
 #include "DetectorsRaw/RDHUtils.h"
 #include <fairlogger/Logger.h>
 
@@ -162,7 +162,7 @@ void AltroDecoder::readChannels(const std::vector<uint32_t>& buffer, CaloRawFitt
           short chiAddr = absId;
           chiAddr |= caloFlag << 14;
           mOutputFitChi.emplace_back(chiAddr);
-          mOutputFitChi.emplace_back(short(5 * rawFitter->getChi2())); // 0.2 accuracy
+          mOutputFitChi.emplace_back(short(std::min(5.f * rawFitter->getChi2(), float(SHRT_MAX - 1)))); // 0.2 accuracy
         }
         if (fitResult == CaloRawFitter::FitStatus::kOK || fitResult == CaloRawFitter::FitStatus::kNoTime) {
           if (!mPedestalRun) {
