Re #16959 applied feedback

Framework/Algorithms/src/GeneralisedSecondDifference.cpp

@@ -143,7 +143,7 @@ void GeneralisedSecondDifference::computePrefactors() {
     m_Cij.resize(3);
     m_Cij.assign(previous.begin(), previous.end());
     m_Cij2.resize(3);
-    std::transform(m_Cij.begin(), m_Cij.end(), m_Cij2.begin(),
+    std::transform(m_Cij.cbegin(), m_Cij.cend(), m_Cij2.begin(),
                    VectorHelper::Squares<double>());
     return;
   }
@@ -163,9 +163,7 @@ void GeneralisedSecondDifference::computePrefactors() {
           next[i] += previous[index];
       }
     }
-    previous.resize(n_el);
-    std::copy(next.begin(), next.end(), previous.begin());
-    previous.assign(next.begin(), next.end());
+	previous = next;
     max_index_prev = max_index;
     n_el_prev = n_el;
   } while (zz != m_z);
@@ -173,7 +171,7 @@ void GeneralisedSecondDifference::computePrefactors() {
   m_Cij.resize(2 * m_z * m_m + 3);
   m_Cij.assign(previous.begin(), previous.end());
   m_Cij2.resize(2 * m_z * m_m + 3);
-  std::transform(m_Cij.begin(), m_Cij.end(), m_Cij2.begin(),
+  std::transform(m_Cij.cbegin(), m_Cij.cend(), m_Cij2.begin(),
                  VectorHelper::Squares<double>());
 }
 

Framework/Algorithms/src/GetEi.cpp

@@ -377,9 +377,12 @@ void GetEi::getPeakEstimates(double &height, int64_t &centreInd,
   height = Y[0];
   centreInd = 0;
 
+  background = std::accumulate(Y.begin(), Y.end(), 0.0);
   // then loop through all the Y values and find the tallest peak
-  std::accumulate(Y.begin(), Y.end(), background);
-  std::max(Y.begin(), Y.end(), height);
+  // Todo use std::max to find max element and record index?
+  auto maxHeight = std::max_element(Y.begin(), Y.end());
+  height = *maxHeight;
+  centreInd = std::distance(Y.begin(), maxHeight);
 
   background = background / static_cast<double>(Y.size());
   if (height < PEAK_THRESH_H * background) {