public void returns_undefined_for_a_set_of_all_positive_numbers()
{
//arrange
var inputData = new[] { 1.0, 1.0, 2.0, 3.0 };
//act
var lossStdDev = inputData.LossStandardDeviation();
//assert
Assert.AreEqual(double.NaN, lossStdDev);
}
public void returns_undefined_with_single_negative_input()
{
//arrange
var inputData = new[] { -1.0 };
//act
var lossStdDev = inputData.LossStandardDeviation();
//assert
Assert.AreEqual(double.NaN, lossStdDev);
}
public void handles_zero_in_the_data_input_as_a_positive_number()
{
//arrange
var inputData = new[] { -1.0, 0.0, -6.0, 2.0 };
var expectedLossStdDeviation = inputData.Where(x => x < 0).StandardDeviation();
//act
var lossStdDev = inputData.LossStandardDeviation();
//assert
Assert.AreEqual(expectedLossStdDeviation, lossStdDev);
}
public void does_not_use_positive_input_data()
{
//arrange
var inputData = new[] { -1.0, 1.0, -2.0, 2.0 };
var expectedLossStdDeviation = inputData.Where(x => x < 0).StandardDeviation();
//act
var lossStdDev = inputData.LossStandardDeviation();
//assert
Assert.AreEqual(expectedLossStdDeviation, lossStdDev);
}