/** Process WorkspaceGroup inputs.
 *
 * Overriden from Algorithm base class.
 *
 * This should be called after checkGroups(), which sets up required members.
 * It goes through each member of the group(s), creates and sets an algorithm
 * for each and executes them one by one.
 *
 * If there are several group input workspaces, then the member of each group
 * is executed pair-wise.
 *
 * @param sourceAlg : Source algorithm
 * @param vecMultiPeriodGroups : Vector of pre-identified multiperiod groups.
 * @return true - if all the workspace members are executed.
 */
bool MultiPeriodGroupWorker::processGroups(
    Algorithm *const sourceAlg,
    const VecWSGroupType &vecMultiPeriodGroups) const {
  // If we are not processing multiperiod groups, use the base behaviour.
  if (vecMultiPeriodGroups.empty()) {
    return false; // Indicates that this is not a multiperiod group workspace.
  }
  Property *outputWorkspaceProperty = sourceAlg->getProperty("OutputWorkspace");
  const std::string outName = outputWorkspaceProperty->value();

  const size_t nPeriods = vecMultiPeriodGroups[0]->size();
  WorkspaceGroup_sptr outputWS = boost::make_shared<WorkspaceGroup>();
  AnalysisDataService::Instance().addOrReplace(outName, outputWS);

  double progress_proportion = 1.0 / static_cast<double>(nPeriods);
  // Loop through all the periods. Create spawned algorithms of the same type as
  // this to process pairs from the input groups.
  for (size_t i = 0; i < nPeriods; ++i) {
    const int periodNumber = static_cast<int>(i + 1);
    // use create Child Algorithm that look like this one
    Algorithm_sptr alg = sourceAlg->createChildAlgorithm(
        sourceAlg->name(), progress_proportion * periodNumber,
        progress_proportion * (1 + periodNumber), sourceAlg->isLogging(),
        sourceAlg->version());
    if (!alg) {
      throw std::runtime_error("Algorithm creation failed.");
    }
    // Don't make the new algorithm a child so that it's workspaces are stored
    // correctly
    alg->setChild(false);
    alg->setRethrows(true);
    alg->initialize();
    // Copy properties that aren't workspaces properties.
    sourceAlg->copyNonWorkspaceProperties(alg.get(), periodNumber);

    if (this->useCustomWorkspaceProperty()) {
      const std::string inputWorkspaces =
          createFormattedInputWorkspaceNames(i, vecMultiPeriodGroups);
      // Set the input workspace property.
      alg->setPropertyValue(this->m_workspacePropertyName, inputWorkspaces);
    } else {
      // Configure input properties that are group workspaces.
      copyInputWorkspaceProperties(alg.get(), sourceAlg, periodNumber);
    }
    const std::string outName_i = outName + "_" + Strings::toString(i + 1);
    alg->setPropertyValue("OutputWorkspace", outName_i);
    // Run the spawned algorithm.
    if (!alg->execute()) {
      throw std::runtime_error("Execution of " + sourceAlg->name() +
                               " for group entry " + Strings::toString(i + 1) +
                               " failed.");
    }
    // Add the output workpace from the spawned algorithm to the group.
    outputWS->add(outName_i);
  }

  sourceAlg->setProperty("OutputWorkspace", outputWS);

  return true;
}
/**
 * Run new CompareWorkspaces algorithm as a child algorithm.
 *
 * Result string formatted the same way as before; "Success!" when workspaces
 * match or a newline separated list of mismatch messages.
 *
 * @param group_compare Should output be formatted like group comparison?
 * @return A string containing either successString() or mismatch messages
 */
std::string CheckWorkspacesMatch::runCompareWorkspaces(bool group_compare) {
  // This algorithm produces a single result string
  std::string result;

  // Use new CompareWorkspaces algorithm to perform comparison
  Algorithm_sptr compare = this->createChildAlgorithm("CompareWorkspaces");
  compare->setRethrows(true);
  compare->setLogging(false);

  // Forward workspace properties
  Workspace_sptr ws1 = getProperty("Workspace1");
  Workspace_sptr ws2 = getProperty("Workspace2");
  compare->setProperty("Workspace1", ws1);
  compare->setProperty("Workspace2", ws2);

  // Copy any other non-default properties
  const std::vector<Property *> &allProps = this->getProperties();
  auto propCount = allProps.size();
  for (size_t i = 0; i < propCount; ++i) {
    Property *prop = allProps[i];
    const std::string &pname = prop->name();

    if (!prop->isDefault() && pname != "Workspace1" && pname != "Workspace2" &&
        pname != "Result")
      compare->setPropertyValue(pname, prop->value());
  }

  // Execute comparison
  compare->execute();

  // Generate result string
  if (!compare->getProperty("Result")) {
    ITableWorkspace_sptr table = compare->getProperty("Messages");
    auto rowcount = table->rowCount();
    for (size_t i = 0; i < rowcount; ++i) {
      result += table->cell<std::string>(i, 0);

      // Emulate special case output format when comparing groups
      if (group_compare &&
          table->cell<std::string>(i, 0) !=
              "Type mismatch. One workspace is a group, the other is not." &&
          table->cell<std::string>(i, 0) != "GroupWorkspaces size mismatch.") {

        result += ". Inputs=[" + table->cell<std::string>(i, 1) + "," +
                  table->cell<std::string>(i, 2) + "]";
      }

      if (i < (rowcount - 1))
        result += "\n";
    }
  } else {
    result = successString();
  }

  return result;
}
bool ReflectometryReductionOneAuto::processGroups() {
    auto group = AnalysisDataService::Instance().retrieveWS<WorkspaceGroup>(
                     getPropertyValue("InputWorkspace"));
    const std::string outputIvsQ = this->getPropertyValue("OutputWorkspace");
    const std::string outputIvsLam =
        this->getPropertyValue("OutputWorkspaceWavelength");

    // Create a copy of ourselves
    Algorithm_sptr alg = this->createChildAlgorithm(
                             this->name(), -1, -1, this->isLogging(), this->version());
    alg->setChild(false);
    alg->setRethrows(true);

    // Copy all the non-workspace properties over
    std::vector<Property *> props = this->getProperties();
    for (auto prop = props.begin(); prop != props.end(); ++prop) {
        if (*prop) {
            IWorkspaceProperty *wsProp = dynamic_cast<IWorkspaceProperty *>(*prop);
            if (!wsProp)
                alg->setPropertyValue((*prop)->name(), (*prop)->value());
        }
    }

    // Check if the transmission runs are groups or not
    const std::string firstTrans = this->getPropertyValue("FirstTransmissionRun");
    WorkspaceGroup_sptr firstTransG;
    if (!firstTrans.empty()) {
        auto firstTransWS =
            AnalysisDataService::Instance().retrieveWS<Workspace>(firstTrans);
        firstTransG = boost::dynamic_pointer_cast<WorkspaceGroup>(firstTransWS);

        if (!firstTransG)
            alg->setProperty("FirstTransmissionRun", firstTrans);
        else if (group->size() != firstTransG->size())
            throw std::runtime_error("FirstTransmissionRun WorkspaceGroup must be "
                                     "the same size as the InputWorkspace "
                                     "WorkspaceGroup");
    }

    const std::string secondTrans =
        this->getPropertyValue("SecondTransmissionRun");
    WorkspaceGroup_sptr secondTransG;
    if (!secondTrans.empty()) {
        auto secondTransWS =
            AnalysisDataService::Instance().retrieveWS<Workspace>(secondTrans);
        secondTransG = boost::dynamic_pointer_cast<WorkspaceGroup>(secondTransWS);

        if (!secondTransG)
            alg->setProperty("SecondTransmissionRun", secondTrans);
        else if (group->size() != secondTransG->size())
            throw std::runtime_error("SecondTransmissionRun WorkspaceGroup must be "
                                     "the same size as the InputWorkspace "
                                     "WorkspaceGroup");
    }

    std::vector<std::string> IvsQGroup, IvsLamGroup;

    // Execute algorithm over each group member (or period, if this is
    // multiperiod)
    size_t numMembers = group->size();
    for (size_t i = 0; i < numMembers; ++i) {
        const std::string IvsQName =
            outputIvsQ + "_" + boost::lexical_cast<std::string>(i + 1);
        const std::string IvsLamName =
            outputIvsLam + "_" + boost::lexical_cast<std::string>(i + 1);

        alg->setProperty("InputWorkspace", group->getItem(i)->name());
        alg->setProperty("OutputWorkspace", IvsQName);
        alg->setProperty("OutputWorkspaceWavelength", IvsLamName);

        // Handle transmission runs
        if (firstTransG)
            alg->setProperty("FirstTransmissionRun", firstTransG->getItem(i)->name());
        if (secondTransG)
            alg->setProperty("SecondTransmissionRun",
                             secondTransG->getItem(i)->name());

        alg->execute();

        IvsQGroup.push_back(IvsQName);
        IvsLamGroup.push_back(IvsLamName);

        // We use the first group member for our thetaout value
        if (i == 0)
            this->setPropertyValue("ThetaOut", alg->getPropertyValue("ThetaOut"));
    }

    // Group the IvsQ and IvsLam workspaces
    Algorithm_sptr groupAlg = this->createChildAlgorithm("GroupWorkspaces");
    groupAlg->setChild(false);
    groupAlg->setRethrows(true);

    groupAlg->setProperty("InputWorkspaces", IvsLamGroup);
    groupAlg->setProperty("OutputWorkspace", outputIvsLam);
    groupAlg->execute();

    groupAlg->setProperty("InputWorkspaces", IvsQGroup);
    groupAlg->setProperty("OutputWorkspace", outputIvsQ);
    groupAlg->execute();

    // If this is a multiperiod workspace and we have polarization corrections
    // enabled
    if (this->getPropertyValue("PolarizationAnalysis") !=
            noPolarizationCorrectionMode()) {
        if (group->isMultiperiod()) {
            // Perform polarization correction over the IvsLam group
            Algorithm_sptr polAlg =
                this->createChildAlgorithm("PolarizationCorrection");
            polAlg->setChild(false);
            polAlg->setRethrows(true);

            polAlg->setProperty("InputWorkspace", outputIvsLam);
            polAlg->setProperty("OutputWorkspace", outputIvsLam);
            polAlg->setProperty("PolarizationAnalysis",
                                this->getPropertyValue("PolarizationAnalysis"));
            polAlg->setProperty("CPp", this->getPropertyValue(cppLabel()));
            polAlg->setProperty("CRho", this->getPropertyValue(crhoLabel()));
            polAlg->setProperty("CAp", this->getPropertyValue(cApLabel()));
            polAlg->setProperty("CAlpha", this->getPropertyValue(cAlphaLabel()));
            polAlg->execute();

            // Now we've overwritten the IvsLam workspaces, we'll need to recalculate
            // the IvsQ ones
            alg->setProperty("FirstTransmissionRun", "");
            alg->setProperty("SecondTransmissionRun", "");
            for (size_t i = 0; i < numMembers; ++i) {
                const std::string IvsQName =
                    outputIvsQ + "_" + boost::lexical_cast<std::string>(i + 1);
                const std::string IvsLamName =
                    outputIvsLam + "_" + boost::lexical_cast<std::string>(i + 1);
                alg->setProperty("InputWorkspace", IvsLamName);
                alg->setProperty("OutputWorkspace", IvsQName);
                alg->setProperty("OutputWorkspaceWavelength", IvsLamName);
                alg->execute();
            }
        } else {
            g_log.warning("Polarization corrections can only be performed on "
                          "multiperiod workspaces.");
        }
    }

    // We finished successfully
    this->setPropertyValue("OutputWorkspace", outputIvsQ);
    this->setPropertyValue("OutputWorkspaceWavelength", outputIvsLam);
    setExecuted(true);
    notificationCenter().postNotification(
        new FinishedNotification(this, isExecuted()));
    return true;
}
/** Process groups. Groups are processed differently depending on transmission
 * runs and polarization analysis. If transmission run is a matrix workspace, it
 * will be applied to each of the members in the input workspace group. If
 * transmission run is a workspace group, the behaviour is different depending
 * on polarization analysis. If polarization analysis is off (i.e.
 * 'PolarizationAnalysis' is set to 'None') each item in the transmission group
 * is associated with the corresponding item in the input workspace group. If
 * polarization analysis is on (i.e. 'PolarizationAnalysis' is 'PA' or 'PNR')
 * items in the transmission group will be summed to produce a matrix workspace
 * that will be applied to each of the items in the input workspace group. See
 * documentation of this algorithm for more details.
*/
bool ReflectometryReductionOneAuto2::processGroups() {
  // this algorithm effectively behaves as MultiPeriodGroupAlgorithm
  m_usingBaseProcessGroups = true;

  // Get our input workspace group
  auto group = AnalysisDataService::Instance().retrieveWS<WorkspaceGroup>(
      getPropertyValue("InputWorkspace"));
  // Get name of IvsQ workspace (native binning)
  const std::string outputIvsQ = getPropertyValue("OutputWorkspace");
  // Get name of IvsQ (native binning) workspace
  const std::string outputIvsQBinned =
      getPropertyValue("OutputWorkspaceBinned");
  // Get name of IvsLam workspace
  const std::string outputIvsLam =
      getPropertyValue("OutputWorkspaceWavelength");

  // Create a copy of ourselves
  Algorithm_sptr alg =
      createChildAlgorithm(name(), -1, -1, isLogging(), version());
  alg->setChild(false);
  alg->setRethrows(true);

  // Copy all the non-workspace properties over
  const std::vector<Property *> props = getProperties();
  for (auto &prop : props) {
    if (prop) {
      IWorkspaceProperty *wsProp = dynamic_cast<IWorkspaceProperty *>(prop);
      if (!wsProp)
        alg->setPropertyValue(prop->name(), prop->value());
    }
  }

  const bool polarizationAnalysisOn =
      getPropertyValue("PolarizationAnalysis") != "None";

  // Check if the transmission runs are groups or not

  const std::string firstTrans = getPropertyValue("FirstTransmissionRun");
  WorkspaceGroup_sptr firstTransG;
  MatrixWorkspace_sptr firstTransSum;
  if (!firstTrans.empty()) {
    auto firstTransWS =
        AnalysisDataService::Instance().retrieveWS<Workspace>(firstTrans);
    firstTransG = boost::dynamic_pointer_cast<WorkspaceGroup>(firstTransWS);
    if (!firstTransG) {
      alg->setProperty("FirstTransmissionRun", firstTrans);
    } else if (polarizationAnalysisOn) {
      firstTransSum = sumTransmissionWorkspaces(firstTransG);
    }
  }
  const std::string secondTrans = getPropertyValue("SecondTransmissionRun");
  WorkspaceGroup_sptr secondTransG;
  MatrixWorkspace_sptr secondTransSum;
  if (!secondTrans.empty()) {
    auto secondTransWS =
        AnalysisDataService::Instance().retrieveWS<Workspace>(secondTrans);
    secondTransG = boost::dynamic_pointer_cast<WorkspaceGroup>(secondTransWS);
    if (!secondTransG) {
      alg->setProperty("SecondTransmissionRun", secondTrans);
    } else if (polarizationAnalysisOn) {
      secondTransSum = sumTransmissionWorkspaces(secondTransG);
    }
  }

  std::vector<std::string> IvsQGroup, IvsQUnbinnedGroup, IvsLamGroup;

  // Execute algorithm over each group member
  for (size_t i = 0; i < group->size(); ++i) {

    const std::string IvsQName = outputIvsQ + "_" + std::to_string(i + 1);
    const std::string IvsQBinnedName =
        outputIvsQBinned + "_" + std::to_string(i + 1);
    const std::string IvsLamName = outputIvsLam + "_" + std::to_string(i + 1);

    if (firstTransG) {
      if (!polarizationAnalysisOn)
        alg->setProperty("FirstTransmissionRun",
                         firstTransG->getItem(i)->getName());
      else
        alg->setProperty("FirstTransmissionRun", firstTransSum);
    }
    if (secondTransG) {
      if (!polarizationAnalysisOn)
        alg->setProperty("SecondTransmissionRun",
                         secondTransG->getItem(i)->getName());
      else
        alg->setProperty("SecondTransmissionRun", secondTransSum);
    }

    alg->setProperty("InputWorkspace", group->getItem(i)->getName());
    alg->setProperty("OutputWorkspace", IvsQName);
    alg->setProperty("OutputWorkspaceBinned", IvsQBinnedName);
    alg->setProperty("OutputWorkspaceWavelength", IvsLamName);
    alg->execute();

    IvsQGroup.push_back(IvsQName);
    IvsQUnbinnedGroup.push_back(IvsQBinnedName);
    IvsLamGroup.push_back(IvsLamName);
  }

  // Group the IvsQ and IvsLam workspaces
  Algorithm_sptr groupAlg = createChildAlgorithm("GroupWorkspaces");
  groupAlg->setChild(false);
  groupAlg->setRethrows(true);
  groupAlg->setProperty("InputWorkspaces", IvsLamGroup);
  groupAlg->setProperty("OutputWorkspace", outputIvsLam);
  groupAlg->execute();
  groupAlg->setProperty("InputWorkspaces", IvsQGroup);
  groupAlg->setProperty("OutputWorkspace", outputIvsQ);
  groupAlg->execute();
  groupAlg->setProperty("InputWorkspaces", IvsQUnbinnedGroup);
  groupAlg->setProperty("OutputWorkspace", outputIvsQBinned);
  groupAlg->execute();

  // Set other properties so they can be updated in the Reflectometry interface
  setPropertyValue("ThetaIn", alg->getPropertyValue("ThetaIn"));
  setPropertyValue("MomentumTransferMin",
                   alg->getPropertyValue("MomentumTransferMin"));
  setPropertyValue("MomentumTransferMax",
                   alg->getPropertyValue("MomentumTransferMax"));
  setPropertyValue("MomentumTransferStep",
                   alg->getPropertyValue("MomentumTransferStep"));
  setPropertyValue("ScaleFactor", alg->getPropertyValue("ScaleFactor"));

  if (!polarizationAnalysisOn) {
    // No polarization analysis. Reduction stops here
    setPropertyValue("OutputWorkspace", outputIvsQ);
    setPropertyValue("OutputWorkspaceBinned", outputIvsQBinned);
    setPropertyValue("OutputWorkspaceWavelength", outputIvsLam);
    return true;
  }

  if (!group->isMultiperiod()) {
    g_log.warning("Polarization corrections can only be performed on "
                  "multiperiod workspaces.");
    setPropertyValue("OutputWorkspace", outputIvsQ);
    setPropertyValue("OutputWorkspaceBinned", outputIvsQBinned);
    setPropertyValue("OutputWorkspaceWavelength", outputIvsLam);
    return true;
  }

  Algorithm_sptr polAlg = createChildAlgorithm("PolarizationCorrection");
  polAlg->setChild(false);
  polAlg->setRethrows(true);
  polAlg->setProperty("InputWorkspace", outputIvsLam);
  polAlg->setProperty("OutputWorkspace", outputIvsLam);
  polAlg->setProperty("PolarizationAnalysis",
                      getPropertyValue("PolarizationAnalysis"));
  polAlg->setProperty("CPp", getPropertyValue("CPp"));
  polAlg->setProperty("CRho", getPropertyValue("CRho"));
  polAlg->setProperty("CAp", getPropertyValue("CAp"));
  polAlg->setProperty("CAlpha", getPropertyValue("CAlpha"));
  polAlg->execute();

  // Now we've overwritten the IvsLam workspaces, we'll need to recalculate
  // the IvsQ ones
  alg->setProperty("FirstTransmissionRun", "");
  alg->setProperty("SecondTransmissionRun", "");
  alg->setProperty("CorrectionAlgorithm", "None");
  alg->setProperty("ThetaIn", Mantid::EMPTY_DBL());
  alg->setProperty("ProcessingInstructions", "0");
  for (size_t i = 0; i < group->size(); ++i) {
    const std::string IvsQName = outputIvsQ + "_" + std::to_string(i + 1);
    const std::string IvsQBinnedName =
        outputIvsQBinned + "_" + std::to_string(i + 1);
    const std::string IvsLamName = outputIvsLam + "_" + std::to_string(i + 1);
    alg->setProperty("InputWorkspace", IvsLamName);
    alg->setProperty("OutputWorkspace", IvsQName);
    alg->setProperty("OutputWorkspaceBinned", IvsQBinnedName);
    alg->setProperty("OutputWorkspaceWavelength", IvsLamName);
    alg->execute();
  }

  setPropertyValue("OutputWorkspace", outputIvsQ);
  setPropertyValue("OutputWorkspaceBinned", outputIvsQBinned);
  setPropertyValue("OutputWorkspaceWavelength", outputIvsLam);

  return true;
}
bool ReflectometryReductionOneAuto::processGroups() {
  // isPolarizationCorrectionOn is used to decide whether
  // we should process our Transmission WorkspaceGroup members
  // as individuals (not multiperiod) when PolarizationCorrection is off,
  // or sum over all of the workspaces in the group
  // and used that sum as our TransmissionWorkspace when PolarizationCorrection
  // is on.
  const bool isPolarizationCorrectionOn =
      this->getPropertyValue("PolarizationAnalysis") !=
      noPolarizationCorrectionMode();
  // Get our input workspace group
  auto group = AnalysisDataService::Instance().retrieveWS<WorkspaceGroup>(
      getPropertyValue("InputWorkspace"));
  // Get name of IvsQ workspace
  const std::string outputIvsQ = this->getPropertyValue("OutputWorkspace");
  // Get name of IvsLam workspace
  const std::string outputIvsLam =
      this->getPropertyValue("OutputWorkspaceWavelength");

  // Create a copy of ourselves
  Algorithm_sptr alg = this->createChildAlgorithm(
      this->name(), -1, -1, this->isLogging(), this->version());
  alg->setChild(false);
  alg->setRethrows(true);

  // Copy all the non-workspace properties over
  std::vector<Property *> props = this->getProperties();
  for (auto &prop : props) {
    if (prop) {
      IWorkspaceProperty *wsProp = dynamic_cast<IWorkspaceProperty *>(prop);
      if (!wsProp)
        alg->setPropertyValue(prop->name(), prop->value());
    }
  }

  // Check if the transmission runs are groups or not
  const std::string firstTrans = this->getPropertyValue("FirstTransmissionRun");
  WorkspaceGroup_sptr firstTransG;
  if (!firstTrans.empty()) {
    auto firstTransWS =
        AnalysisDataService::Instance().retrieveWS<Workspace>(firstTrans);
    firstTransG = boost::dynamic_pointer_cast<WorkspaceGroup>(firstTransWS);

    if (!firstTransG) {
      // we only have one transmission workspace, so we use it as it is.
      alg->setProperty("FirstTransmissionRun", firstTrans);
    } else if (group->size() != firstTransG->size() &&
               !isPolarizationCorrectionOn) {
      // if they are not the same size then we cannot associate a transmission
      // group workspace member with every input group workpspace member.
      throw std::runtime_error("FirstTransmissionRun WorkspaceGroup must be "
                               "the same size as the InputWorkspace "
                               "WorkspaceGroup");
    }
  }

  const std::string secondTrans =
      this->getPropertyValue("SecondTransmissionRun");
  WorkspaceGroup_sptr secondTransG;
  if (!secondTrans.empty()) {
    auto secondTransWS =
        AnalysisDataService::Instance().retrieveWS<Workspace>(secondTrans);
    secondTransG = boost::dynamic_pointer_cast<WorkspaceGroup>(secondTransWS);

    if (!secondTransG)
      // we only have one transmission workspace, so we use it as it is.
      alg->setProperty("SecondTransmissionRun", secondTrans);

    else if (group->size() != secondTransG->size() &&
             !isPolarizationCorrectionOn) {
      // if they are not the same size then we cannot associate a transmission
      // group workspace member with every input group workpspace member.
      throw std::runtime_error("SecondTransmissionRun WorkspaceGroup must be "
                               "the same size as the InputWorkspace "
                               "WorkspaceGroup");
    }
  }
  std::vector<std::string> IvsQGroup, IvsLamGroup;

  // Execute algorithm over each group member (or period, if this is
  // multiperiod)
  size_t numMembers = group->size();
  for (size_t i = 0; i < numMembers; ++i) {
    const std::string IvsQName =
        outputIvsQ + "_" + boost::lexical_cast<std::string>(i + 1);
    const std::string IvsLamName =
        outputIvsLam + "_" + boost::lexical_cast<std::string>(i + 1);

    // If our transmission run is a group and PolarizationCorrection is on
    // then we sum our transmission group members.
    //
    // This is done inside of the for loop to avoid the wrong workspace being
    // used when these arguments are passed through to the exec() method.
    // If this is not set in the loop, exec() will fetch the first workspace
    // from the specified Transmission Group workspace that the user entered.
    if (firstTransG && isPolarizationCorrectionOn) {
      auto firstTransmissionSum = sumOverTransmissionGroup(firstTransG);
      alg->setProperty("FirstTransmissionRun", firstTransmissionSum);
    }
    if (secondTransG && isPolarizationCorrectionOn) {
      auto secondTransmissionSum = sumOverTransmissionGroup(secondTransG);
      alg->setProperty("SecondTransmissionRun", secondTransmissionSum);
    }

    // Otherwise, if polarization correction is off, we process them
    // using one transmission group member at a time.
    if (firstTransG && !isPolarizationCorrectionOn) // polarization off
      alg->setProperty("FirstTransmissionRun", firstTransG->getItem(i)->name());
    if (secondTransG && !isPolarizationCorrectionOn) // polarization off
      alg->setProperty("SecondTransmissionRun",
                       secondTransG->getItem(i)->name());

    alg->setProperty("InputWorkspace", group->getItem(i)->name());
    alg->setProperty("OutputWorkspace", IvsQName);
    alg->setProperty("OutputWorkspaceWavelength", IvsLamName);
    alg->execute();

    MatrixWorkspace_sptr tempFirstTransWS =
        alg->getProperty("FirstTransmissionRun");

    IvsQGroup.push_back(IvsQName);
    IvsLamGroup.push_back(IvsLamName);

    // We use the first group member for our thetaout value
    if (i == 0)
      this->setPropertyValue("ThetaOut", alg->getPropertyValue("ThetaOut"));
  }

  // Group the IvsQ and IvsLam workspaces
  Algorithm_sptr groupAlg = this->createChildAlgorithm("GroupWorkspaces");
  groupAlg->setChild(false);
  groupAlg->setRethrows(true);

  groupAlg->setProperty("InputWorkspaces", IvsLamGroup);
  groupAlg->setProperty("OutputWorkspace", outputIvsLam);
  groupAlg->execute();

  groupAlg->setProperty("InputWorkspaces", IvsQGroup);
  groupAlg->setProperty("OutputWorkspace", outputIvsQ);
  groupAlg->execute();

  // If this is a multiperiod workspace and we have polarization corrections
  // enabled
  if (isPolarizationCorrectionOn) {
    if (group->isMultiperiod()) {
      // Perform polarization correction over the IvsLam group
      Algorithm_sptr polAlg =
          this->createChildAlgorithm("PolarizationCorrection");
      polAlg->setChild(false);
      polAlg->setRethrows(true);

      polAlg->setProperty("InputWorkspace", outputIvsLam);
      polAlg->setProperty("OutputWorkspace", outputIvsLam);
      polAlg->setProperty("PolarizationAnalysis",
                          this->getPropertyValue("PolarizationAnalysis"));
      polAlg->setProperty("CPp", this->getPropertyValue(cppLabel()));
      polAlg->setProperty("CRho", this->getPropertyValue(crhoLabel()));
      polAlg->setProperty("CAp", this->getPropertyValue(cApLabel()));
      polAlg->setProperty("CAlpha", this->getPropertyValue(cAlphaLabel()));
      polAlg->execute();

      // Now we've overwritten the IvsLam workspaces, we'll need to recalculate
      // the IvsQ ones
      alg->setProperty("FirstTransmissionRun", "");
      alg->setProperty("SecondTransmissionRun", "");
      for (size_t i = 0; i < numMembers; ++i) {
        const std::string IvsQName =
            outputIvsQ + "_" + boost::lexical_cast<std::string>(i + 1);
        const std::string IvsLamName =
            outputIvsLam + "_" + boost::lexical_cast<std::string>(i + 1);
        alg->setProperty("InputWorkspace", IvsLamName);
        alg->setProperty("OutputWorkspace", IvsQName);
        alg->setProperty("CorrectionAlgorithm", "None");
        alg->setProperty("OutputWorkspaceWavelength", IvsLamName);
        alg->execute();
      }
    } else {
      g_log.warning("Polarization corrections can only be performed on "
                    "multiperiod workspaces.");
    }
  }

  // We finished successfully
  this->setPropertyValue("OutputWorkspace", outputIvsQ);
  this->setPropertyValue("OutputWorkspaceWavelength", outputIvsLam);
  setExecuted(true);
  notificationCenter().postNotification(
      new FinishedNotification(this, isExecuted()));
  return true;
}