uses MLABC;

begin
  var df := CsvLoader.Load('towns_russia.csv',
    inferCategorical := true);
  
  df := df.Select([
    'population',
    'lat',
    'lon',
    'region_name',
    'federal_district'
  ]);
  
  // Препроцессинг
  var imputer := new Imputer(['population', 'lat', 'lon']);
  df := imputer.FitTransform(df);
  
  var le1 := new OrdinalEncoder('region_name');
  df := le1.FitTransform(df);
  
  var le2 := new OrdinalEncoder('federal_district');
  df := le2.FitTransform(df);
  
  // Явно задаём признаки
  var features := ['lat', 'lon', 'region_name', 'federal_district'];
  
  var X := df.ToMatrix(features);
  var y := df.ToVector('population');
  
  // Модель
  var model := new LinearRegression;
  model.Fit(X, y);
  
  var preds := model.Predict(X);
  
  Println('RMSE:', Metrics.RMSE(y, preds):0:3);
end.