ModelEvaluatorRegression.cs

public class ModelEvaluator
{
    /// <summary>
    /// Ussing passed testing data and model, it calculates model's accuracy.
    /// </summary>
    /// <returns>Accuracy of the model.</returns>
    public RegressionMetrics Evaluate(PredictionModel<BikeSharingDemandSample, BikeSharingDemandPrediction> model, string testDataLocation)
    {
        var testData = new TextLoader(testDataLocation).CreateFrom<BikeSharingDemandSample>(useHeader: true, separator: ',');
        var metrics = new RegressionEvaluator().Evaluate(model, testData);
        return metrics;
    }
}