void writePopulationStructure() {

    List<String[]> populationParams = new ArrayList<String[]>();
    populationParams.add(new String[] {"NumberOfDemes", "" + numberOfDemes});
    populationParams.add(new String[] {"NetworkType", popType.toString()});
    populationParams.add(new String[] {"Directed", dirType});

    if (popType.equals(PopulationType.RANDOM)) {
      populationParams.add(new String[] {"ProbabilityConnect", "" + probConnect});
    }

    populationParams.add(new String[] {"ModelType", modelType.toString()});
    populationParams.add(infectionParams);
    populationParams.add(new String[] {"DemeType", demeType});
    populationParams.add(new String[] {"NumberOfHostsPerDeme", "" + hostsInDeme});
    populationParams.add(new String[] {"ProbabilityInfectionAnyOtherDeme", "" + pinfectother});

    populationParams.add(new String[] {"ReportSummary", reportSummary});

    logFile.write("<PopulationStructure>");
    logFile.writeParametersXML(populationParams, 1);
    logFile.write("</PopulationStructure>");
  }
 @Override
 public void setModelType(String mt) {
   this.modelType = ModelType.valueOf(mt);
 }