gammainc_test.go

// Copyright (c) 2018, Jack Parkinson. All rights reserved.
// Use of this source code is governed by the BSD 3-Clause
// license that can be found in the LICENSE file.

package special_test

import (
	"testing"

	. "scientificgo.org/special"
	"scientificgo.org/testutil"
)

var casesGammaIncU = []struct {
	Label         string
	In1, In2, Out float64
}{
	{"", nan, 2, nan},
	{"", 20, -2.432, nan},
	{"", 10, 0, 362880},
	{"", 10, +inf, 0},
	{"", 0, 10, 4.156968929685325e-06},
	{"", -1, 10, 3.830240465631609e-07},
	{"", -10, 10, 2.2146903192202743e-16},
	{"", -10, 27, 2.420076067270557e-28},
	{"", 10, 10, 166173.53478754574},
	{"", 10, 1, 362879.95956592244},
	{"", -10.2, 1.99, 9.893689107832149e-06},
}

var casesGammaIncL = []struct {
	Label         string
	In1, In2, Out float64
}{
	{"", nan, 2, nan},
	{"", -10, nan, nan},
	{"", 20, -2.432, nan},
	{"", 10, 0, 0},
	{"", 10, +inf, 362880},
	{"", -10, 10, +inf},
	{"", 10, 100, 362880},
	{"", 10, 1000, 362880},
	{"", 100, 1000, 9.332621544394415e+155},
	{"", 10, 0.001, 9.990913256294004e-32},
	{"", -11.2, 1.99, -4.522214610043099e-06},
}

var casesGammaIncIdentity = []struct {
	Label         string
	In1, In2, Out float64
}{
	{"", nan, 2, nan},
	{"", -10, nan, nan},
	{"", 20, -2.432, nan},
	{"", +inf, 12.2, nan},
	{"", 10, +inf, 362880},
	{"", 10, 43, 362880},
	{"", 50.5, 94.3, 4.290462912351957e+63},
	{"", 150.5, 94.3, 4.661072627097374e+261},
	{"", 150.5, 194.3, 4.661072627097374e+261},
	{"", 150.5, 1.943e+07, 4.661072627097374e+261},
}

func TestGammaIncU(t *testing.T) { testutil.Test(t, tol, casesGammaIncU, GammaIncU) }
func TestGammaIncL(t *testing.T) { testutil.Test(t, tol, casesGammaIncL, GammaIncL) }
func TestGammaIncIdentity(t *testing.T) {
	identity := func(a, x float64) float64 {
		return GammaIncU(a, x) + GammaIncL(a, x)
	}
	testutil.Test(t, tol, casesGammaIncIdentity, identity)
}

/*
func BenchmarkGammaIncU(b *testing.B) {
	GlobalF = bench(b, cGammaIncU, "",
		func(x []float64) float64 {
			return GammaIncU(x[0], x[1])
		})
}
func BenchmarkGammaIncL(b *testing.B) {
	GlobalF = bench(b, cGammaIncL, "",
		func(x []float64) float64 {
			return GammaIncL(x[0], x[1])
		})
}
*/