blob: 15f158e5f0f24638cd3421251b35423ff23aeb69 [file] [log] [blame]
 // Copyright ©2016 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 mathext import ( "math" "testing" "gonum.org/v1/gonum/floats" ) var result float64 func TestDigamma(t *testing.T) { const tol = 1e-10 for i, test := range []struct { x, want float64 }{ // Results computed using WolframAlpha. {0.0, math.Inf(-1)}, {math.Copysign(0.0, -1.0), math.Inf(1)}, {math.Inf(1), math.Inf(1)}, {math.Inf(-1), math.NaN()}, {math.NaN(), math.NaN()}, {-1.0, math.NaN()}, {-100.5, 4.615124601338064117341315601525112558522917517910505881343}, {.5, -1.96351002602142347944097633299875556719315960466043}, {10, 2.251752589066721107647456163885851537211808918028330369448}, {math.Pow10(20), 46.05170185988091368035482909368728415202202143924212618733}, {-1.111111111e9, math.NaN()}, {1.46, -0.001580561987083417676105544023567034348339520110000}, } { got := Digamma(test.x) if !(math.IsNaN(got) && math.IsNaN(test.want)) && !floats.EqualWithinAbsOrRel(got, test.want, tol, tol) { t.Errorf("test %d Digamma(%g) failed: got %g want %g", i, test.x, got, test.want) } } } func BenchmarkDigamma(b *testing.B) { var r float64 for i := 0; i < b.N; i++ { r = Digamma(-1.111111111e9) } result = r }