parseCSVFile method

Future<ARFF> parseCSVFile({ required String fileName, })

Implementation

Future<ARFF> parseCSVFile({required String fileName}) async {
  final fileContent = await rootBundle.loadString(fileName);
  final lines = fileContent.split('\n');
  String relation = fileName;
  List<ARFFAttributes> attributesList = [];
  List<List<ARFFData>> arffData = [];

  if (lines.isEmpty) return ARFF(relation, attributesList, arffData);

  List<String> header = lines.first
      .split(',')
      .map((h) => h.trim().replaceAll('"', ''))
      .toList();
  lines.removeAt(0);

  List<Set<String>> nominalValues =
      List.generate(header.length, (_) => <String>{});
  List<bool> isNumericColumn = List.generate(header.length, (_) => true);

  for (var line in lines) {
    line = line.trim();
    if (line.isEmpty) continue;

    final values =
        line.split(',').map((v) => v.trim().replaceAll('"', '')).toList();

    for (int i = 0; i < values.length; i++) {
      final value = values[i];

      if (double.tryParse(value) == null) {
        isNumericColumn[i] = false;
        nominalValues[i].add(value);
      }
    }
  }

  for (int i = 0; i < header.length; i++) {
    final name = header[i];

    if (isNumericColumn[i]) {
      attributesList.add(ARFFAttributes(name, 'numeric'));
    } else {
      attributesList
          .add(ARFFAttributes(name, 'nominal', nominalValues[i].toList()));
    }
  }
  for (var line in lines) {
    final values =
        line.split(',').map((v) => v.trim().replaceAll('"', '')).toList();
    List<ARFFData> arffDtList = [];
    for (int index = 0; index < attributesList.length; index++) {
      ARFFData arffDt =
          ARFFData(name: attributesList[index].name, value: values[index]);
      arffDtList.add(arffDt);
    }

    arffData.add(arffDtList);
  }
  return ARFF(relation, attributesList, arffData);
}