Re #16959 changed for loop to std funcs

Framework/Algorithms/src/GetAllEi.cpp

@@ -381,12 +381,12 @@ void GetAllEi::exec() {
   std::transform(peaks.cbegin(), peaks.cend(), peaks_positions.begin(),
                  [](peakKeeper peak) { return peak.position; });
   auto &Signal =
-      result_ws->mutableY(0); // Signal[i] = peaks[i].height; to transform
+      result_ws->mutableY(0); 
   std::transform(peaks.cbegin(), peaks.cend(), Signal.begin(),
                  [](peakKeeper peak) { return peak.height; });
 
   auto &Error =
-      result_ws->mutableE(0); // Error[i] = peaks[i].sigma; to transform
+      result_ws->mutableE(0);
   std::transform(peaks.cbegin(), peaks.cend(), Error.begin(),
                  [](peakKeeper peak) { return peak.sigma; });
 
@@ -746,7 +746,7 @@ namespace { // for lambda extracted from findBinRanges
 void getBinRange(const HistogramData::HistogramX &eBins, double eMin,
                  double eMax, size_t &index_min, size_t &index_max) {
 
-  auto bins = eBins.rawData();
+  auto &bins = eBins.rawData();
   size_t nBins = bins.size();
   if (eMin <= bins[0]) {
     index_min = 0;
@@ -891,7 +891,7 @@ GetAllEi::buildWorkspaceToFit(const API::MatrixWorkspace_sptr &inputWS,
   // auto bins       = inputWS->dataX(wsIndex0);
   auto bins = pSpectr1.ptrX();
   size_t XLength = bins->size();
-  size_t YLength = inputWS->mutableY(wsIndex0).size();
+  size_t YLength = inputWS->y(wsIndex0).size();
   auto working_ws =
       API::WorkspaceFactory::Instance().create(inputWS, 2, XLength, YLength);
   // copy data --> very bad as implicitly assigns pointer

Framework/Algorithms/src/GetEi.cpp

@@ -10,6 +10,7 @@
 
 #include <boost/lexical_cast.hpp>
 #include <cmath>
+#include <numeric>
 
 namespace Mantid {
 namespace Algorithms {
@@ -377,14 +378,9 @@ void GetEi::getPeakEstimates(double &height, int64_t &centreInd,
   centreInd = 0;
 
   // then loop through all the Y values and find the tallest peak
-  for (size_t i = 1; i < Y.size() - 1; ++i) {
-    background += Y[i];
-    if (Y[i] > height) {
-      centreInd = i;
-      height = Y[centreInd];
-    }
-  }
-
+  std::accumulate(Y.begin(), Y.end(), background);
+  std::max(Y.begin(), Y.end(), height);
+ 
   background = background / static_cast<double>(Y.size());
   if (height < PEAK_THRESH_H * background) {
     throw std::invalid_argument(