| // Copyright ©2017 The Gonum Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package distuv |
| |
| import ( |
| "math" |
| "sort" |
| "testing" |
| |
| "golang.org/x/exp/rand" |
| |
| "gonum.org/v1/gonum/floats/scalar" |
| ) |
| |
| func TestParetoProb(t *testing.T) { |
| t.Parallel() |
| for _, test := range []struct { |
| x, xm, alpha, want float64 |
| }{ |
| {0, 1, 1, 0}, |
| {0.5, 1, 1, 0}, |
| {1, 1, 1, 1.0}, |
| {1.5, 1, 1, 0.444444444444444}, |
| {2, 1, 1, 0.25}, |
| {2.5, 1, 1, 0.16}, |
| {3, 1, 1, 0.1111111111111111}, |
| {3.5, 1, 1, 0.081632653061224}, |
| {4, 1, 1, 0.0625}, |
| {4.5, 1, 1, 0.049382716049383}, |
| {5, 1, 1, 0.04}, |
| |
| {0, 1, 2, 0}, |
| {0.5, 1, 2, 0}, |
| {1, 1, 2, 2}, |
| {1.5, 1, 2, 0.592592592592593}, |
| {2, 1, 2, 0.25}, |
| {2.5, 1, 2, 0.128}, |
| {3, 1, 2, 0.074074074074074}, |
| {3.5, 1, 2, 0.046647230320700}, |
| {4, 1, 2, 0.03125}, |
| {4.5, 1, 2, 0.021947873799726}, |
| {5, 1, 2, 0.016}, |
| |
| {0, 1, 3, 0}, |
| {0.5, 1, 3, 0}, |
| {1, 1, 3, 3.0}, |
| {1.5, 1, 3, 0.592592592592593}, |
| {2, 1, 3, 0.1875}, |
| {2.5, 1, 3, 0.0768}, |
| {3, 1, 3, 0.037037037037037}, |
| {3.5, 1, 3, 0.019991670137443}, |
| {4, 1, 3, 0.011718750000000}, |
| {4.5, 1, 3, 0.007315957933242}, |
| {5, 1, 3, 0.0048}, |
| } { |
| pdf := Pareto{test.xm, test.alpha, nil}.Prob(test.x) |
| if !scalar.EqualWithinAbsOrRel(pdf, test.want, 1e-10, 1e-10) { |
| t.Errorf("Pdf mismatch, x = %v, xm = %v, alpha = %v. Got %v, want %v", test.x, test.xm, test.alpha, pdf, test.want) |
| } |
| } |
| } |
| |
| func TestParetoCDF(t *testing.T) { |
| t.Parallel() |
| for _, test := range []struct { |
| x, xm, alpha, want float64 |
| }{ |
| {0, 1, 1, 0}, |
| {0.5, 1, 1, 0}, |
| {1, 1, 1, 0}, |
| {1.5, 1, 1, 0.333333333333333}, |
| {2, 1, 1, 0.5}, |
| {2.5, 1, 1, 0.6}, |
| {3, 1, 1, 0.666666666666667}, |
| {3.5, 1, 1, 0.714285714285714}, |
| {4, 1, 1, 0.75}, |
| {4.5, 1, 1, 0.777777777777778}, |
| {5, 1, 1, 0.80}, |
| {5.5, 1, 1, 0.818181818181818}, |
| {6, 1, 1, 0.833333333333333}, |
| {6.5, 1, 1, 0.846153846153846}, |
| {7, 1, 1, 0.857142857142857}, |
| {7.5, 1, 1, 0.866666666666667}, |
| {8, 1, 1, 0.875}, |
| {8.5, 1, 1, 0.882352941176471}, |
| {9, 1, 1, 0.888888888888889}, |
| {9.5, 1, 1, 0.894736842105263}, |
| {10, 1, 1, 0.90}, |
| |
| {0, 1, 2, 0}, |
| {0.5, 1, 2, 0}, |
| {1, 1, 2, 0}, |
| {1.5, 1, 2, 0.555555555555556}, |
| {2, 1, 2, 0.75}, |
| {2.5, 1, 2, 0.84}, |
| {3, 1, 2, 0.888888888888889}, |
| {3.5, 1, 2, 0.918367346938776}, |
| {4, 1, 2, 0.9375}, |
| {4.5, 1, 2, 0.950617283950617}, |
| {5, 1, 2, 0.96}, |
| {5.5, 1, 2, 0.966942148760331}, |
| {6, 1, 2, 0.972222222222222}, |
| {6.5, 1, 2, 0.976331360946746}, |
| {7, 1, 2, 0.979591836734694}, |
| {7.5, 1, 2, 0.982222222222222}, |
| {8, 1, 2, 0.984375000000000}, |
| {8.5, 1, 2, 0.986159169550173}, |
| {9, 1, 2, 0.987654320987654}, |
| {9.5, 1, 2, 0.988919667590028}, |
| {10, 1, 2, 0.99}, |
| |
| {0, 1, 3, 0}, |
| {0.5, 1, 3, 0}, |
| {1, 1, 3, 0}, |
| {1.5, 1, 3, 0.703703703703704}, |
| {2, 1, 3, 0.875}, |
| {2.5, 1, 3, 0.936}, |
| {3, 1, 3, 0.962962962962963}, |
| {3.5, 1, 3, 0.976676384839650}, |
| {4, 1, 3, 0.984375000000000}, |
| {4.5, 1, 3, 0.989026063100137}, |
| {5, 1, 3, 0.992}, |
| {5.5, 1, 3, 0.993989481592787}, |
| {6, 1, 3, 0.995370370370370}, |
| {6.5, 1, 3, 0.996358670914884}, |
| {7, 1, 3, 0.997084548104956}, |
| {7.5, 1, 3, 0.997629629629630}, |
| {8, 1, 3, 0.998046875000000}, |
| {8.5, 1, 3, 0.998371667005903}, |
| {9, 1, 3, 0.998628257887517}, |
| {9.5, 1, 3, 0.998833649220003}, |
| {10, 1, 3, 0.999}, |
| } { |
| cdf := Pareto{test.xm, test.alpha, nil}.CDF(test.x) |
| if !scalar.EqualWithinAbsOrRel(cdf, test.want, 1e-10, 1e-10) { |
| t.Errorf("CDF mismatch, x = %v, xm = %v, alpha = %v. Got %v, want %v", test.x, test.xm, test.alpha, cdf, test.want) |
| } |
| } |
| } |
| |
| func TestPareto(t *testing.T) { |
| t.Parallel() |
| src := rand.New(rand.NewSource(1)) |
| for i, p := range []Pareto{ |
| {1, 10, src}, |
| {1, 20, src}, |
| } { |
| testPareto(t, p, i) |
| } |
| } |
| |
| func testPareto(t *testing.T, p Pareto, i int) { |
| const ( |
| tol = 1e-2 |
| n = 1e6 |
| bins = 50 |
| ) |
| x := make([]float64, n) |
| generateSamples(x, p) |
| sort.Float64s(x) |
| |
| checkQuantileCDFSurvival(t, i, x, p, 1e-3) |
| testRandLogProbContinuous(t, i, 0, x, p, tol, bins) |
| checkMean(t, i, x, p, tol) |
| checkVarAndStd(t, i, x, p, tol) |
| checkExKurtosis(t, i, x, p, 7e-2) |
| checkProbContinuous(t, i, x, p.Xm, math.Inf(1), p, 1e-10) |
| checkEntropy(t, i, x, p, 1e-2) |
| checkMedian(t, i, x, p, 1e-3) |
| |
| if p.Xm != p.Mode() { |
| t.Errorf("Mismatch in mode value: got %v, want %g", p.Mode(), p.Xm) |
| } |
| if p.NumParameters() != 2 { |
| t.Errorf("Mismatch in NumParameters: got %v, want 2", p.NumParameters()) |
| } |
| surv := p.Survival(p.Xm - 0.0001) |
| if surv != 1 { |
| t.Errorf("Mismatch in Survival below Xm: got %v, want 1", surv) |
| } |
| } |
| |
| func TestParetoNotExists(t *testing.T) { |
| t.Parallel() |
| p := Pareto{0, 4, nil} |
| exKurt := p.ExKurtosis() |
| if !math.IsNaN(exKurt) { |
| t.Errorf("Expected NaN excess kurtosis for Alpha == 4, got %v", exKurt) |
| } |
| p = Pareto{0, 1, nil} |
| mean := p.Mean() |
| if !math.IsInf(mean, 1) { |
| t.Errorf("Expected mean == +Inf for Alpha == 1, got %v", mean) |
| } |
| p = Pareto{0, 2, nil} |
| variance := p.Variance() |
| if !math.IsInf(variance, 1) { |
| t.Errorf("Expected variance == +Inf for Alpha == 1, got %v", variance) |
| } |
| stdDev := p.StdDev() |
| if !math.IsInf(stdDev, 1) { |
| t.Errorf("Expected standard deviation == +Inf for Alpha == 1, got %v", stdDev) |
| } |
| } |