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51 lines
1.3 KiB
Go
51 lines
1.3 KiB
Go
// Copyright ©2016 The Gonum Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package mathext
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import (
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"math"
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"testing"
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"gonum.org/v1/gonum/floats"
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)
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var result float64
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func TestDigamma(t *testing.T) {
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const tol = 1e-10
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for i, test := range []struct {
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x, want float64
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}{
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// Results computed using WolframAlpha.
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{0.0, math.Inf(-1)},
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{math.Copysign(0.0, -1.0), math.Inf(1)},
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{math.Inf(1), math.Inf(1)},
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{math.Inf(-1), math.NaN()},
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{math.NaN(), math.NaN()},
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{-1.0, math.NaN()},
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{-100.5, 4.615124601338064117341315601525112558522917517910505881343},
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{.5, -1.96351002602142347944097633299875556719315960466043},
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{10, 2.251752589066721107647456163885851537211808918028330369448},
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{math.Pow10(20), 46.05170185988091368035482909368728415202202143924212618733},
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{-1.111111111e9, math.NaN()},
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{1.46, -0.001580561987083417676105544023567034348339520110000},
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} {
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got := Digamma(test.x)
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if !(math.IsNaN(got) && math.IsNaN(test.want)) && !floats.EqualWithinAbsOrRel(got, test.want, tol, tol) {
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t.Errorf("test %d Digamma(%g) failed: got %g want %g", i, test.x, got, test.want)
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}
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}
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}
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func BenchmarkDigamma(b *testing.B) {
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var r float64
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for i := 0; i < b.N; i++ {
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r = Digamma(-1.111111111e9)
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}
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result = r
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}
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