Fixed a typo in the "qwparity" instructions in README.md and found a bug

for ALMA9 compilation.

In the README.md, the instructions for running "qwparity" had a typo;
the commandline flag to specify the data handler map file should be
"--datahandlers".

Then, running with the data handlers active on the ALMA9 machines, we
found a segfault during the program initiallization due to a
non-initialized pointer in the VQwDataHandler class.  That pointer is
now explicitly zeroed during construction.

The correlator and the linear regression corrector are now executed, but
we need to verify that their opperation is correct.

Parity/src/VQwDataHandler.cc

@@ -44,7 +44,7 @@ VQwDataHandler::VQwDataHandler(const TString& name)
   fSubsystemArray(0),
   fHelicityPattern(0),
   fKeepRunningSum(kFALSE)
-{ }
+{ fRunningsum=NULL;}
 
 VQwDataHandler::VQwDataHandler(const VQwDataHandler &source)
 : fPriority(source.fPriority),
@@ -70,7 +70,11 @@ VQwDataHandler::VQwDataHandler(const VQwDataHandler &source)
     this->fOutputVar[i] = source.fOutputVar[i]->Clone(VQwDataElement::kDerived);
     //this->fOutputVar[i] = new QwVQWK_Channel(*vqwk, VQwDataElement::kDerived);
   }
-
+  if (source.fRunningsum!=NULL){
+    fRunningsum = source.fRunningsum->Clone();
+  } else {
+    fRunningsum = NULL;
+  }
 }
 
 

README.md

@@ -49,7 +49,7 @@ build/qwmockdatagenerator -r 4 -e 1:20000 --config qwparity_simple.conf --detect
 
 The command to analyze that mock-data file and produce a root file is:
 ```
-build/qwparity -r 4 --config qwparity_simple.conf --detectors mock_newdets.map --data-handler mock_datahandlers.map --data . --rootfiles .
+build/qwparity -r 4 --config qwparity_simple.conf --detectors mock_newdets.map --datahandlers mock_datahandlers.map --data . --rootfiles .
 ```
 
 The parameter files are searched for within the Parity/prminputs directory.