Refs #4980 use reduce in GatherWorkspaces

mantidproject · Mar 16, 2012 · cd334a4 · cd334a4
1 parent e5aa854
commit cd334a4
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Showing 2 changed files with 40 additions and 37 deletions.
diff --git a/Code/Mantid/Framework/MPIAlgorithms/inc/MantidMPIAlgorithms/GatherWorkspaces.h b/Code/Mantid/Framework/MPIAlgorithms/inc/MantidMPIAlgorithms/GatherWorkspaces.h
@@ -60,10 +60,44 @@ class GatherWorkspaces : public API::Algorithm
   virtual int version() const { return (1); }
   /// Algorithm's category for identification
   virtual const std::string category() const { return "MPI"; }
+  /// Sum for boostmpi MantidVec
+  struct vplus
+        : public std::binary_function<MantidVec, MantidVec, MantidVec>
+  {       // functor for operator+
+        MantidVec operator()(const MantidVec& _Left, const MantidVec& _Right) const
+        {       // apply operator+ to operands
+                MantidVec v(_Left.size());
+                std::transform(_Left.begin(), _Left.end(), _Right.begin(), v.begin(), std::plus<double>());
+                return (v);
+        }
+
+  };
+   /// Sum for error for boostmpi MantidVec
+  struct eplus : public std::binary_function<MantidVec, MantidVec, MantidVec>
+  {       // functor for operator+
+        MantidVec operator()(const MantidVec& _Left, const MantidVec& _Right) const
+        {       // apply operator+ to operands
+                MantidVec v(_Left.size());
+                std::transform(_Left.begin(), _Left.end(), _Right.begin(), v.begin(), SumGaussError<double>());
+                return (v);
+        }
+  };
+
 
 private:
   void init();
   void exec();
+  //! Functor used for computing the sum of the square values of a vector, using the accumulate algorithm
+  template <class T> struct SumGaussError: public std::binary_function<T,T,T>
+  {
+    SumGaussError(){}
+    /// Sums the arguments in quadrature
+    inline T operator()(const T& l, const T& r) const
+    {
+      return std::sqrt(l*l+r*r);
+    }
+  };
+
   //void execEvent(); TODO: Make event-aware? (might lead to transmission of too much data)
 
 };

diff --git a/Code/Mantid/Framework/MPIAlgorithms/src/GatherWorkspaces.cpp b/Code/Mantid/Framework/MPIAlgorithms/src/GatherWorkspaces.cpp
@@ -79,59 +79,28 @@ void GatherWorkspaces::exec()
   {
     g_log.debug() << "Total number of spectra is " << totalSpec << "\n";
     // Create the workspace for the output
-    outputWorkspace = WorkspaceFactory::Instance().create(inputWorkspace,totalSpec,numBins+hist,numBins);
+    outputWorkspace = WorkspaceFactory::Instance().create(inputWorkspace,1,numBins+hist,numBins);
     setProperty("OutputWorkspace",outputWorkspace);
-
-    // Keep it lean-and-mean and don't bother with the spectra map, etc.
-    // This line is needed to stop a crash on a subsequent SaveNexus
-//    outputWorkspace->replaceSpectraMap(new SpectraDetectorMap);
   }
 
   // Let's assume 1 spectrum in each workspace for the first try....
   // TODO: Generalise
 
+  MantidVec out;
   if ( world.rank() == 0 )
   {
-    // Copy over data from own input workspace
     outputWorkspace->dataX(0) = inputWorkspace->readX(0);
-    outputWorkspace->dataY(0) = inputWorkspace->readY(0);
-    outputWorkspace->dataE(0) = inputWorkspace->readE(0);
+    reduce(included, inputWorkspace->readY(0), outputWorkspace->dataY(0), vplus(), 0);
+    reduce(included, inputWorkspace->readE(0), outputWorkspace->dataE(0), eplus(), 0);
     const ISpectrum * inSpec = inputWorkspace->getSpectrum(0);
     ISpectrum * outSpec = outputWorkspace->getSpectrum(0);
     outSpec->clearDetectorIDs();
     outSpec->addDetectorIDs( inSpec->getDetectorIDs() );
-
-    const int numReqs(3*(included.size()-1));
-    mpi::request reqs[numReqs];
-    int j(0);
-
-    // Receive data from all the other processes
-    // This works because the process ranks are ordered the same in 'included' as
-    // they are in 'world', but in general this is not guaranteed. TODO: robustify
-    for ( int i = 1; i < included.size(); ++i )
-    {
-      reqs[j++] = included.irecv(i,0,outputWorkspace->dataX(i));
-      reqs[j++] = included.irecv(i,1,outputWorkspace->dataY(i));
-      reqs[j++] = included.irecv(i,2,outputWorkspace->dataE(i));
-      ISpectrum * outSpec = outputWorkspace->getSpectrum(i);
-      outSpec->clearDetectorIDs();
-      outSpec->addDetectorIDs( inSpec->getDetectorIDs() );
-    }
-
-    // Make sure everything's been received before exiting the algorithm
-    mpi::wait_all(reqs,reqs+numReqs);
   }
   else
   {
-    mpi::request reqs[3];
-
-    // Send the spectrum to the root process
-    reqs[0] = included.isend(0,0,inputWorkspace->readX(0));
-    reqs[1] = included.isend(0,1,inputWorkspace->readY(0));
-    reqs[2] = included.isend(0,2,inputWorkspace->readE(0));
-
-    // Make sure the sends have completed before exiting the algorithm
-    mpi::wait_all(reqs,reqs+3);
+    reduce(included, inputWorkspace->readY(0), vplus(), 0);
+    reduce(included, inputWorkspace->readE(0), eplus(), 0);
   }
 
 }