| package stats |
| |
| import ( |
| "math" |
| "testing" |
| |
| "github.com/stretchr/testify/assert" |
| "github.com/stretchr/testify/require" |
| ) |
| |
| const tol = 0.0001 |
| |
| func TestZeroIn_GivenFuncInputsWithoutZero_ReturnsError(t *testing.T) { |
| // Cannot find root |
| root, err := zeroin(1.96, 0, 0.5, tol, []float64{1, 2}, TwoSided, true, asymptoticW) |
| require.Error(t, err) |
| assert.True(t, math.IsNaN(root)) |
| } |
| |
| func TestZeroIn_GivenFunctionNaN_ContinuesCalculation(t *testing.T) { |
| // f(a) = 0 |
| expected := 0.0 |
| root, err := zeroin(1.96, 0, 0, tol, []float64{0, 0, 0, 0, 0}, TwoSided, true, asymptoticW) |
| require.NoError(t, err) |
| assert.InDelta(t, expected, root, tol) |
| |
| // f(b) = 0 |
| expected = 0.9999 |
| root, err = zeroin(1.96, 0.3, 1.0, tol, []float64{1, 1}, TwoSided, true, asymptoticW) |
| require.NoError(t, err) |
| assert.InDelta(t, expected, root, tol) |
| } |
| |
| func TestZeroIn_GivenFaVsFb_ReturnsCorrectResult(t *testing.T) { |
| zq := 1.9599 |
| nums := []float64{141, 15, -411, -753, -169, 696, -522, 98, -24, 696, -452} |
| expected := -411.0000 |
| |
| test := func(name string, a, b float64, correct bool) { |
| t.Run(name, func(t *testing.T) { |
| result, err := zeroin(zq, a, b, tol, nums, TwoSided, correct, asymptoticW) |
| require.NoError(t, err) |
| assert.InDelta(t, expected, result, tol) |
| }) |
| } |
| test("verify result for math.Abs(fa) < math.Abs(fb)", -753, 696, true) |
| test("verify result for math.Abs(fa) >= math.Abs(fb)", 696, -753, true) |
| } |
| |
| func TestZeroIn_GivenDifferentHypothesis_ReturnsCorrectResult(t *testing.T) { |
| test := func(name string, zq, a, b float64, nums []float64, alt Hypothesis, correct bool, expected float64) { |
| t.Run(name, func(t *testing.T) { |
| result, err := zeroin(zq, a, b, tol, nums, alt, correct, asymptoticW) |
| require.NoError(t, err) |
| assert.InDelta(t, expected, result, tol) |
| }) |
| } |
| nums := []float64{141, 15, -411, -753, -169, 696, -522, 98, -24, 696, -452} |
| test("alternative hypothesis = Less", 1.9599, 696, -753, nums, Less, true, -388.500067) |
| |
| nums = []float64{-555, 258, -193, -209, 18, -408, -593, -121, 296, 86, -246, -481, 23} |
| test("alternative hypothesis = TwoSided", 1.6448, -593, 296, nums, TwoSided, true, -327.0000) |
| test("alternative hypothesis = Greater", 1.6448, -593, 296, nums, Greater, true, -327.0000) |
| } |
| |
| func TestZeroIn_GivenFalseCorrection_ReturnsCorrectResult(t *testing.T) { |
| nums := []float64{-555, 258, -193, -209, 18, -408, -593, -121, 296, 86, -246, -481, 23} |
| result, err := zeroin(1.6448, -593, 296, tol, nums, TwoSided, false, asymptoticW) |
| require.NoError(t, err) |
| assert.InDelta(t, -326.9999, result, tol) |
| } |
