Refs #5534 extended ftq_Re and fqt_Im to negative times

modified: LoadSassena.cpp modified: LoadSassenaTest.h
mantidproject · Jun 23, 2012 · 1f38dad · 1f38dad
1 parent 8e6ea00
commit 1f38dad
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Showing 2 changed files with 19 additions and 10 deletions.
diff --git a/Code/Mantid/Framework/DataHandling/src/LoadSassena.cpp b/Code/Mantid/Framework/DataHandling/src/LoadSassena.cpp
@@ -182,7 +182,8 @@ void LoadSassena::loadFQ(const hid_t& h5file, API::WorkspaceGroup_sptr gws, cons
 }
 
 /**
- * Create one workspace to hold the real part and another to hold the imaginary part
+ * Create one workspace to hold the real part and another to hold the imaginary part.
+ * We symmetrize the structure factor to negative times
  * Y-values are structure factor for each Q-value
  * X-values are time bins
  * @param h5file file identifier
@@ -197,8 +198,10 @@ void LoadSassena::loadFQT(const hid_t& h5file, API::WorkspaceGroup_sptr gws, con
   double dt = 1.0; //time unit increment;
   hsize_t dims[3];
   this->dataSetInfo(h5file, setName, dims);
-  int nt = static_cast<int>( dims[1] ); //number of time points
-  double* buf = new double[nq*nt*2];
+  int nnt = static_cast<int>( dims[1] ); //number of non-negative time points
+  int nt = 2*nnt - 1; //number of time points
+  int origin = nnt-1;
+  double* buf = new double[nq*nnt*2];
   this->dataSetDouble(h5file,setName,buf);
 
   DataObjects::Workspace2D_sptr wsRe = boost::dynamic_pointer_cast<DataObjects::Workspace2D>(API::WorkspaceFactory::Instance().create("Workspace2D", nq, nt, nt));
@@ -216,13 +219,17 @@ void LoadSassena::loadFQT(const hid_t& h5file, API::WorkspaceGroup_sptr gws, con
     MantidVec& imX = wsIm->dataX(iq);
     MantidVec& reY = wsRe->dataY(iq);
     MantidVec& imY = wsIm->dataY(iq);
-    for(int it=0; it<nt; it++)
+    for(int it=0; it<nnt; it++)
     {
-      reX[it] = it*dt;  // time point for the real part
-      reY[it] = *curr;  // real part of the intermediate structure factor
+      reX[origin+it] = it*dt;  // time point for the real part
+      reY[origin+it] = *curr;  // real part of the intermediate structure factor
+      reX[origin-it] = -it*dt; // symmetric negative time
+      reY[origin-it] = *curr;  // symmetric value for the negative time
       curr ++;
-      imX[it] = it*dt;
-      imY[it] = *curr;
+      imX[origin+it] = it*dt;
+      imY[origin+it] = *curr;
+      imX[origin-it] = -it*dt;
+      imY[origin-it] = *curr;
       curr ++;
     }
   }

diff --git a/Code/Mantid/Framework/DataHandling/test/LoadSassenaTest.h b/Code/Mantid/Framework/DataHandling/test/LoadSassenaTest.h
@@ -70,11 +70,13 @@ class LoadSassenaTest : public CxxTest::TestSuite
 
     //Test fq Real part
     ws = boost::dynamic_pointer_cast<DataObjects::Workspace2D>( gws->getItem("outGWS_fqt.Re") );
-    TS_ASSERT_DELTA( ws->readY(4)[7], 1918.2156, 1e-04 );
+    TS_ASSERT_DELTA( ws->readY(4)[0], 1918.2156, 1e-04 );
+    TS_ASSERT_DELTA( ws->readY(4)[14], 1918.2156, 1e-04 );
 
     //Test fq Imaginary part
     ws = boost::dynamic_pointer_cast<DataObjects::Workspace2D>( gws->getItem("outGWS_fqt.Im") );
-    TS_ASSERT_DELTA( ws->readY(4)[7], 656.82368, 1e-05 );
+    TS_ASSERT_DELTA( ws->readY(4)[0], 656.82368, 1e-05 );
+    TS_ASSERT_DELTA( ws->readY(4)[14], 656.82368, 1e-05 );
 
   } // end of testExec