mirror of
https://github.com/gonum/gonum.git
synced 2025-10-31 18:42:45 +08:00
127 lines
3.6 KiB
Go
127 lines
3.6 KiB
Go
// Copyright ©2015 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 quad
|
|
|
|
import (
|
|
"math"
|
|
"testing"
|
|
|
|
"gonum.org/v1/gonum/floats"
|
|
"gonum.org/v1/gonum/stat/distuv"
|
|
)
|
|
|
|
func TestFixed(t *testing.T) {
|
|
for i, test := range []struct {
|
|
f func(float64) float64
|
|
min, max float64
|
|
n []int
|
|
tol []float64
|
|
ans float64
|
|
}{
|
|
// Tolerances determined from intuition and a bit of post-hoc tweaking.
|
|
{
|
|
f: func(x float64) float64 { return math.Exp(x) },
|
|
min: -3,
|
|
max: 5,
|
|
n: []int{3, 4, 6, 7, 15, 16, 300, 301},
|
|
tol: []float64{5e-2, 5e-3, 5e-6, 1e-7, 1e-14, 1e-14, 1e-14, 1e-14},
|
|
ans: math.Exp(5) - math.Exp(-3),
|
|
},
|
|
{
|
|
f: distuv.UnitNormal.Prob,
|
|
min: math.Inf(-1),
|
|
max: math.Inf(1),
|
|
n: []int{15, 16, 50, 51, 300, 301},
|
|
tol: []float64{5e-3, 1e-3, 1e-7, 1e-7, 1e-14, 1e-14},
|
|
ans: 1,
|
|
},
|
|
{
|
|
f: func(x float64) float64 { return math.Exp(-x) },
|
|
min: 5,
|
|
max: math.Inf(1),
|
|
n: []int{15, 16, 50, 51, 300, 301},
|
|
tol: []float64{5e-3, 1e-3, 1e-7, 1e-7, 1e-14, 1e-14},
|
|
ans: math.Exp(-5),
|
|
},
|
|
{
|
|
f: func(x float64) float64 { return math.Exp(x) },
|
|
min: math.Inf(-1),
|
|
max: -5,
|
|
n: []int{15, 16, 50, 51, 300, 301},
|
|
tol: []float64{5e-3, 1e-3, 1e-7, 1e-7, 1e-14, 1e-14},
|
|
ans: math.Exp(-5),
|
|
},
|
|
{
|
|
f: func(x float64) float64 { return math.Exp(x) },
|
|
min: 3,
|
|
max: 3,
|
|
n: []int{15, 16, 50, 51, 300, 301},
|
|
tol: []float64{0, 0, 0, 0, 0, 0},
|
|
ans: 0,
|
|
},
|
|
} {
|
|
for j, n := range test.n {
|
|
ans := Fixed(test.f, test.min, test.max, n, nil, 0)
|
|
if !floats.EqualWithinAbsOrRel(ans, test.ans, test.tol[j], test.tol[j]) {
|
|
t.Errorf("Case %d, n = %d: Mismatch. Want %v, got %v", i, n, test.ans, ans)
|
|
}
|
|
ans2 := Fixed(test.f, test.min, test.max, n, nil, 3)
|
|
if !floats.EqualWithinAbsOrRel(ans2, test.ans, test.tol[j], test.tol[j]) {
|
|
t.Errorf("Case %d, n = %d: Mismatch concurrent. Want %v, got %v", i, n, test.ans, ans)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// legendreNonSingle wraps Legendre but does not implement FixedLocationSingle.
|
|
type legendreNonSingle struct {
|
|
Legendre Legendre
|
|
}
|
|
|
|
func (l legendreNonSingle) FixedLocations(x, weight []float64, min, max float64) {
|
|
l.Legendre.FixedLocations(x, weight, min, max)
|
|
}
|
|
|
|
func TestFixedNonSingle(t *testing.T) {
|
|
// TODO(btracey): Add tests with infinite bounds when we have native support
|
|
// for indefinite integrals.
|
|
for i, test := range []struct {
|
|
f func(float64) float64
|
|
min, max float64
|
|
n []int
|
|
tol []float64
|
|
ans float64
|
|
}{
|
|
// Tolerances determined from intuition and a bit of post-hoc tweaking.
|
|
{
|
|
f: func(x float64) float64 { return math.Exp(x) },
|
|
min: -3,
|
|
max: 5,
|
|
n: []int{3, 4, 6, 7, 15, 16, 300, 301},
|
|
tol: []float64{5e-2, 5e-3, 5e-6, 1e-7, 1e-14, 1e-14, 1e-14, 1e-14},
|
|
ans: math.Exp(5) - math.Exp(-3),
|
|
},
|
|
{
|
|
f: func(x float64) float64 { return math.Exp(x) },
|
|
min: 3,
|
|
max: 3,
|
|
n: []int{3, 4, 6, 7, 15, 16, 300, 301},
|
|
tol: []float64{0, 0, 0, 0, 0, 0, 0, 0},
|
|
ans: 0,
|
|
},
|
|
} {
|
|
for j, n := range test.n {
|
|
ans := Fixed(test.f, test.min, test.max, n, legendreNonSingle{}, 0)
|
|
if !floats.EqualWithinAbsOrRel(ans, test.ans, test.tol[j], test.tol[j]) {
|
|
t.Errorf("Case = %d, n = %d: Mismatch. Want %v, got %v", i, n, test.ans, ans)
|
|
}
|
|
ans2 := Fixed(test.f, test.min, test.max, n, legendreNonSingle{}, 3)
|
|
if !floats.EqualWithinAbsOrRel(ans2, test.ans, test.tol[j], test.tol[j]) {
|
|
t.Errorf("Case = %d, n = %d: Mismatch concurrent. Want %v, got %v", i, n, test.ans, ans)
|
|
}
|
|
}
|
|
}
|
|
}
|