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// Copyright ©2018 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 hyperdual
import (
"fmt"
"math"
"testing"
"gonum.org/v1/gonum/floats/scalar"
)
var formatTests = []struct {
h Number
format string
want string
}{
{h: Number{1.1, 2.1, 3.1, 4.1}, format: "%#v", want: "hyperdual.Number{Real:1.1, E1mag:2.1, E2mag:3.1, E1E2mag:4.1}"}, // Bootstrap test.
{h: Number{-1.1, -2.1, -3.1, -4.1}, format: "%#v", want: "hyperdual.Number{Real:-1.1, E1mag:-2.1, E2mag:-3.1, E1E2mag:-4.1}"}, // Bootstrap test.
{h: Number{1.1, 2.1, 3.1, 4.1}, format: "%+v", want: "{Real:1.1, E1mag:2.1, E2mag:3.1, E1E2mag:4.1}"},
{h: Number{-1.1, -2.1, -3.1, -4.1}, format: "%+v", want: "{Real:-1.1, E1mag:-2.1, E2mag:-3.1, E1E2mag:-4.1}"},
{h: Number{1, 2, 3, 4}, format: "%v", want: "(1+2ϵ₁+3ϵ₂+4ϵ₁ϵ₂)"},
{h: Number{-1, -2, -3, -4}, format: "%v", want: "(-1-2ϵ₁-3ϵ₂-4ϵ₁ϵ₂)"},
{h: Number{1, 2, 3, 4}, format: "%g", want: "(1+2ϵ₁+3ϵ₂+4ϵ₁ϵ₂)"},
{h: Number{-1, -2, -3, -4}, format: "%g", want: "(-1-2ϵ₁-3ϵ₂-4ϵ₁ϵ₂)"},
{h: Number{1, 2, 3, 4}, format: "%e", want: "(1.000000e+00+2.000000e+00ϵ₁+3.000000e+00ϵ₂+4.000000e+00ϵ₁ϵ₂)"},
{h: Number{-1, -2, -3, -4}, format: "%e", want: "(-1.000000e+00-2.000000e+00ϵ₁-3.000000e+00ϵ₂-4.000000e+00ϵ₁ϵ₂)"},
{h: Number{1, 2, 3, 4}, format: "%E", want: "(1.000000E+00+2.000000E+00ϵ₁+3.000000E+00ϵ₂+4.000000E+00ϵ₁ϵ₂)"},
{h: Number{-1, -2, -3, -4}, format: "%E", want: "(-1.000000E+00-2.000000E+00ϵ₁-3.000000E+00ϵ₂-4.000000E+00ϵ₁ϵ₂)"},
{h: Number{1, 2, 3, 4}, format: "%f", want: "(1.000000+2.000000ϵ₁+3.000000ϵ₂+4.000000ϵ₁ϵ₂)"},
{h: Number{-1, -2, -3, -4}, format: "%f", want: "(-1.000000-2.000000ϵ₁-3.000000ϵ₂-4.000000ϵ₁ϵ₂)"},
}
func TestFormat(t *testing.T) {
t.Parallel()
for _, test := range formatTests {
got := fmt.Sprintf(test.format, test.h)
if got != test.want {
t.Errorf("unexpected result for fmt.Sprintf(%q, %#v): got:%q, want:%q", test.format, test.h, got, test.want)
}
}
}
// First derivatives:
func dSin(x float64) float64 { return math.Cos(x) }
func dCos(x float64) float64 { return -math.Sin(x) }
func dTan(x float64) float64 { return sec(x) * sec(x) }
func dAsin(x float64) float64 { return 1 / math.Sqrt(1-x*x) }
func dAcos(x float64) float64 { return -1 / math.Sqrt(1-x*x) }
func dAtan(x float64) float64 { return 1 / (1 + x*x) }
func dSinh(x float64) float64 { return math.Cosh(x) }
func dCosh(x float64) float64 { return math.Sinh(x) }
func dTanh(x float64) float64 { return sech(x) * sech(x) }
func dAsinh(x float64) float64 { return 1 / math.Sqrt(x*x+1) }
func dAcosh(x float64) float64 { return 1 / (math.Sqrt(x-1) * math.Sqrt(x+1)) }
func dAtanh(x float64) float64 {
switch {
case math.Abs(x) == 1:
return math.NaN()
case math.IsInf(x, 0):
return negZero
}
return 1 / (1 - x*x)
}
func dExp(x float64) float64 { return math.Exp(x) }
func dLog(x float64) float64 {
if x < 0 {
return math.NaN()
}
return 1 / x
}
func dSqrt(x float64) float64 {
// For whatever reason, math.Sqrt(-0) returns -0.
// In this case, that is clearly a wrong approach.
if x == 0 {
return math.Inf(1)
}
return 0.5 / math.Sqrt(x)
}
func dInv(x float64) float64 { return -1 / (x * x) }
// Second derivatives:
func d2Sin(x float64) float64 { return -math.Sin(x) }
func d2Cos(x float64) float64 { return -math.Cos(x) }
func d2Tan(x float64) float64 { return 2 * math.Tan(x) * sec(x) * sec(x) }
func d2Asin(x float64) float64 { return x / math.Pow(1-x*x, 1.5) }
func d2Acos(x float64) float64 { return -x / math.Pow(1-x*x, 1.5) }
func d2Atan(x float64) float64 { return -2 * x / ((x*x + 1) * (x*x + 1)) }
func d2Sinh(x float64) float64 { return math.Sinh(x) }
func d2Cosh(x float64) float64 { return math.Cosh(x) }
func d2Tanh(x float64) float64 { return -2 * math.Tanh(x) * sech(x) * sech(x) }
func d2Asinh(x float64) float64 { return -x / math.Pow((x*x+1), 1.5) }
func d2Acosh(x float64) float64 { return -x / (math.Pow(x-1, 1.5) * math.Pow(x+1, 1.5)) }
func d2Atanh(x float64) float64 { return 2 * x / ((1 - x*x) * (1 - x*x)) }
func d2Exp(x float64) float64 { return math.Exp(x) }
func d2Log(x float64) float64 {
if x < 0 {
return math.NaN()
}
return -1 / (x * x)
}
func d2Sqrt(x float64) float64 {
// Again math.Sqyu, and math.Pow are odd.
switch x {
case math.Inf(1):
return 0
case math.Inf(-1):
return math.NaN()
}
return -0.25 * math.Pow(x, -1.5)
}
func d2Inv(x float64) float64 { return 2 / (x * x * x) }
// Helpers:
func sec(x float64) float64 { return 1 / math.Cos(x) }
func sech(x float64) float64 { return 1 / math.Cosh(x) }
var hyperdualTests = []struct {
name string
x []float64
fnHyperdual func(x Number) Number
fn func(x float64) float64
dFn func(x float64) float64
d2Fn func(x float64) float64
}{
{
name: "sin",
x: []float64{math.NaN(), math.Inf(-1), -3, -2, -1, -0.5, negZero, 0, 0.5, 1, 2, 3, math.Inf(1)},
fnHyperdual: Sin,
fn: math.Sin,
dFn: dSin,
d2Fn: d2Sin,
},
{
name: "cos",
x: []float64{math.NaN(), math.Inf(-1), -3, -2, -1, -0.5, negZero, 0, 0.5, 1, 2, 3, math.Inf(1)},
fnHyperdual: Cos,
fn: math.Cos,
dFn: dCos,
d2Fn: d2Cos,
},
{
name: "tan",
x: []float64{math.NaN(), math.Inf(-1), -3, -2, -1, -0.5, negZero, 0, 0.5, 1, 2, 3, math.Inf(1)},
fnHyperdual: Tan,
fn: math.Tan,
dFn: dTan,
d2Fn: d2Tan,
},
{
name: "sinh",
x: []float64{math.NaN(), math.Inf(-1), -3, -2, -1, -0.5, negZero, 0, 0.5, 1, 2, 3, math.Inf(1)},
fnHyperdual: Sinh,
fn: math.Sinh,
dFn: dSinh,
d2Fn: d2Sinh,
},
{
name: "cosh",
x: []float64{math.NaN(), math.Inf(-1), -3, -2, -1, -0.5, negZero, 0, 0.5, 1, 2, 3, math.Inf(1)},
fnHyperdual: Cosh,
fn: math.Cosh,
dFn: dCosh,
d2Fn: d2Cosh,
},
{
name: "tanh",
x: []float64{math.NaN(), math.Inf(-1), -3, -2, -1, -0.5, negZero, 0, 0.5, 1, 2, 3, math.Inf(1)},
fnHyperdual: Tanh,
fn: math.Tanh,
dFn: dTanh,
d2Fn: d2Tanh,
},
{
name: "asin",
x: []float64{math.NaN(), math.Inf(-1), -3, -2, -1, -0.5, negZero, 0, 0.5, 1, 2, 3, math.Inf(1)},
fnHyperdual: Asin,
fn: math.Asin,
dFn: dAsin,
d2Fn: d2Asin,
},
{
name: "acos",
x: []float64{math.NaN(), math.Inf(-1), -3, -2, -1, -0.5, negZero, 0, 0.5, 1, 2, 3, math.Inf(1)},
fnHyperdual: Acos,
fn: math.Acos,
dFn: dAcos,
d2Fn: d2Acos,
},
{
name: "atan",
x: []float64{math.NaN(), math.Inf(-1), -3, -2, -1, -0.5, negZero, 0, 0.5, 1, 2, 3, math.Inf(1)},
fnHyperdual: Atan,
fn: math.Atan,
dFn: dAtan,
d2Fn: d2Atan,
},
{
name: "asinh",
x: []float64{math.NaN(), math.Inf(-1), -3, -2, -1, -0.5, negZero, 0, 0.5, 1, 2, 3, math.Inf(1)},
fnHyperdual: Asinh,
fn: math.Asinh,
dFn: dAsinh,
d2Fn: d2Asinh,
},
{
name: "acosh",
x: []float64{math.NaN(), math.Inf(-1), -3, -2, -1, -0.5, negZero, 0, 0.5, 1, 2, 3, math.Inf(1)},
fnHyperdual: Acosh,
fn: math.Acosh,
dFn: dAcosh,
d2Fn: d2Acosh,
},
{
name: "atanh",
x: []float64{math.NaN(), math.Inf(-1), -3, -2, -1, -0.5, negZero, 0, 0.5, 1, 2, 3, math.Inf(1)},
fnHyperdual: Atanh,
fn: math.Atanh,
dFn: dAtanh,
d2Fn: d2Atanh,
},
{
name: "exp",
x: []float64{math.NaN(), math.Inf(-1), -3, -2, -1, -0.5, negZero, 0, 0.5, 1, 2, 3, math.Inf(1)},
fnHyperdual: Exp,
fn: math.Exp,
dFn: dExp,
d2Fn: d2Exp,
},
{
name: "log",
x: []float64{math.NaN(), math.Inf(-1), -3, -2, -1, -0.5, negZero, 0, 0.5, 1, 2, 3, math.Inf(1)},
fnHyperdual: Log,
fn: math.Log,
dFn: dLog,
d2Fn: d2Log,
},
{
name: "inv",
x: []float64{math.NaN(), math.Inf(-1), -3, -2, -1, -0.5, negZero, 0, 0.5, 1, 2, 3, math.Inf(1)},
fnHyperdual: Inv,
fn: func(x float64) float64 { return 1 / x },
dFn: dInv,
d2Fn: d2Inv,
},
{
name: "sqrt",
x: []float64{math.NaN(), math.Inf(-1), -3, -2, -1, -0.5, negZero, 0, 0.5, 1, 2, 3, math.Inf(1)},
fnHyperdual: Sqrt,
fn: math.Sqrt,
dFn: dSqrt,
d2Fn: d2Sqrt,
},
{
name: "Fike example fn",
x: []float64{1, 2, 3, 4, 5},
fnHyperdual: func(x Number) Number {
return Mul(
Exp(x),
Inv(Sqrt(
Add(
PowReal(Sin(x), 3),
PowReal(Cos(x), 3)))))
},
fn: func(x float64) float64 {
return math.Exp(x) / math.Sqrt(math.Pow(math.Sin(x), 3)+math.Pow(math.Cos(x), 3))
},
dFn: func(x float64) float64 {
return math.Exp(x) * (3*math.Cos(x) + 5*math.Cos(3*x) + 9*math.Sin(x) + math.Sin(3*x)) /
(8 * math.Pow(math.Pow(math.Sin(x), 3)+math.Pow(math.Cos(x), 3), 1.5))
},
d2Fn: func(x float64) float64 {
return math.Exp(x) * (130 - 12*math.Cos(2*x) + 30*math.Cos(4*x) + 12*math.Cos(6*x) - 111*math.Sin(2*x) + 48*math.Sin(4*x) + 5*math.Sin(6*x)) /
(64 * math.Pow(math.Pow(math.Sin(x), 3)+math.Pow(math.Cos(x), 3), 2.5))
},
},
}
func TestHyperdual(t *testing.T) {
t.Parallel()
const tol = 1e-14
for _, test := range hyperdualTests {
for _, x := range test.x {
fxHyperdual := test.fnHyperdual(Number{Real: x, E1mag: 1, E2mag: 1})
fx := test.fn(x)
dFx := test.dFn(x)
d2Fx := test.d2Fn(x)
if !same(fxHyperdual.Real, fx, tol) {
t.Errorf("unexpected %s(%v): got:%v want:%v", test.name, x, fxHyperdual.Real, fx)
}
if !same(fxHyperdual.E1mag, dFx, tol) {
t.Errorf("unexpected %s′(%v) (ϵ₁): got:%v want:%v", test.name, x, fxHyperdual.E1mag, dFx)
}
if !same(fxHyperdual.E1mag, fxHyperdual.E2mag, tol) {
t.Errorf("mismatched ϵ₁ and ϵ₂ for %s(%v): ϵ₁:%v ϵ₂:%v", test.name, x, fxHyperdual.E1mag, fxHyperdual.E2mag)
}
if !same(fxHyperdual.E1E2mag, d2Fx, tol) {
t.Errorf("unexpected %s′′(%v): got:%v want:%v", test.name, x, fxHyperdual.E1E2mag, d2Fx)
}
}
}
}
var powRealTests = []struct {
d Number
p float64
want Number
}{
// PowReal(NaN+xϵ₁+yϵ₂, ±0) = 1+NaNϵ₁+NaNϵ₂+NaNϵ₁ϵ₂ for any x and y
{d: Number{Real: math.NaN(), E1mag: 0, E2mag: 0}, p: 0, want: Number{Real: 1, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 0, E2mag: 0}, p: negZero, want: Number{Real: 1, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 1, E2mag: 1}, p: 0, want: Number{Real: 1, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 2, E2mag: 2}, p: negZero, want: Number{Real: 1, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 3, E2mag: 3}, p: 0, want: Number{Real: 1, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 1, E2mag: 1}, p: negZero, want: Number{Real: 1, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 2, E2mag: 2}, p: 0, want: Number{Real: 1, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 3, E2mag: 3}, p: negZero, want: Number{Real: 1, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 2, E2mag: 3}, p: 0, want: Number{Real: 1, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 2, E2mag: 3}, p: negZero, want: Number{Real: 1, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
// PowReal(x, ±0) = 1 for any x
{d: Number{Real: 0, E1mag: 0, E2mag: 0}, p: 0, want: Number{Real: 1, E1mag: 0, E2mag: 0}},
{d: Number{Real: math.Inf(1), E1mag: 0, E2mag: 0}, p: 0, want: Number{Real: 1, E1mag: 0, E2mag: 0}},
{d: Number{Real: math.Inf(-1), E1mag: 0, E2mag: 0}, p: negZero, want: Number{Real: 1, E1mag: 0, E2mag: 0}},
{d: Number{Real: 0, E1mag: 1, E2mag: 1}, p: 0, want: Number{Real: 1, E1mag: 0, E2mag: 0}},
{d: Number{Real: math.Inf(1), E1mag: 1, E2mag: 1}, p: 0, want: Number{Real: 1, E1mag: 0, E2mag: 0}},
{d: Number{Real: math.Inf(-1), E1mag: 1, E2mag: 1}, p: negZero, want: Number{Real: 1, E1mag: 0, E2mag: 0}},
// These two satisfy the claim above, but the sign of zero is negative. Do we care?
{d: Number{Real: negZero, E1mag: 0, E2mag: 0}, p: negZero, want: Number{Real: 1, E1mag: negZero, E2mag: negZero}},
{d: Number{Real: negZero, E1mag: 1, E2mag: 1}, p: negZero, want: Number{Real: 1, E1mag: negZero, E2mag: negZero}},
// PowReal(1+xϵ₁+yϵ₂, z) = 1+xzϵ₁+yzϵ₂+2xyzϵ₁ϵ₂ for any z
{d: Number{Real: 1, E1mag: 0, E2mag: 0}, p: 0, want: Number{Real: 1, E1mag: 0, E2mag: 0, E1E2mag: 0}},
{d: Number{Real: 1, E1mag: 0, E2mag: 0}, p: 1, want: Number{Real: 1, E1mag: 0, E2mag: 0, E1E2mag: 0}},
{d: Number{Real: 1, E1mag: 0, E2mag: 0}, p: 2, want: Number{Real: 1, E1mag: 0, E2mag: 0, E1E2mag: 0}},
{d: Number{Real: 1, E1mag: 0, E2mag: 0}, p: 3, want: Number{Real: 1, E1mag: 0, E2mag: 0, E1E2mag: 0}},
{d: Number{Real: 1, E1mag: 1, E2mag: 1}, p: 0, want: Number{Real: 1, E1mag: 0, E2mag: 0, E1E2mag: 0}},
{d: Number{Real: 1, E1mag: 1, E2mag: 1}, p: 1, want: Number{Real: 1, E1mag: 1, E2mag: 1, E1E2mag: 0}},
{d: Number{Real: 1, E1mag: 1, E2mag: 1}, p: 2, want: Number{Real: 1, E1mag: 2, E2mag: 2, E1E2mag: 2}},
{d: Number{Real: 1, E1mag: 1, E2mag: 1}, p: 3, want: Number{Real: 1, E1mag: 3, E2mag: 3, E1E2mag: 6}},
{d: Number{Real: 1, E1mag: 2, E2mag: 2}, p: 0, want: Number{Real: 1, E1mag: 0, E2mag: 0, E1E2mag: 0}},
{d: Number{Real: 1, E1mag: 2, E2mag: 2}, p: 1, want: Number{Real: 1, E1mag: 2, E2mag: 2, E1E2mag: 0}},
{d: Number{Real: 1, E1mag: 2, E2mag: 2}, p: 2, want: Number{Real: 1, E1mag: 4, E2mag: 4, E1E2mag: 8}},
{d: Number{Real: 1, E1mag: 2, E2mag: 2}, p: 3, want: Number{Real: 1, E1mag: 6, E2mag: 6, E1E2mag: 24}},
{d: Number{Real: 1, E1mag: 1, E2mag: 2}, p: 0, want: Number{Real: 1, E1mag: 0, E2mag: 0, E1E2mag: 0}},
{d: Number{Real: 1, E1mag: 1, E2mag: 2}, p: 1, want: Number{Real: 1, E1mag: 1, E2mag: 2, E1E2mag: 0}},
{d: Number{Real: 1, E1mag: 1, E2mag: 2}, p: 2, want: Number{Real: 1, E1mag: 2, E2mag: 4, E1E2mag: 4}},
{d: Number{Real: 1, E1mag: 1, E2mag: 2}, p: 3, want: Number{Real: 1, E1mag: 3, E2mag: 6, E1E2mag: 12}},
// PowReal(NaN+xϵ₁+yϵ₂, 1) = NaN+xϵ₁+yϵ₂+NaNϵ₁ϵ₂ for any x
{d: Number{Real: math.NaN(), E1mag: 0, E2mag: 0}, p: 1, want: Number{Real: math.NaN(), E1mag: 0, E2mag: 0, E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 1, E2mag: 1}, p: 1, want: Number{Real: math.NaN(), E1mag: 1, E2mag: 1, E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 2, E2mag: 2}, p: 1, want: Number{Real: math.NaN(), E1mag: 2, E2mag: 2, E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 1, E2mag: 2}, p: 1, want: Number{Real: math.NaN(), E1mag: 1, E2mag: 2, E1E2mag: math.NaN()}},
// PowReal(x, 1) = x for any x
{d: Number{Real: 0, E1mag: 0, E2mag: 0}, p: 1, want: Number{Real: 0, E1mag: 0, E2mag: 0}},
{d: Number{Real: negZero, E1mag: 0, E2mag: 0}, p: 1, want: Number{Real: negZero, E1mag: 0, E2mag: 0}},
{d: Number{Real: 0, E1mag: 1, E2mag: 1}, p: 1, want: Number{Real: 0, E1mag: 1, E2mag: 1}},
{d: Number{Real: negZero, E1mag: 1, E2mag: 1}, p: 1, want: Number{Real: negZero, E1mag: 1, E2mag: 1}},
{d: Number{Real: 0, E1mag: 1, E2mag: 2}, p: 1, want: Number{Real: 0, E1mag: 1, E2mag: 2}},
{d: Number{Real: negZero, E1mag: 1, E2mag: 2}, p: 1, want: Number{Real: negZero, E1mag: 1, E2mag: 2}},
// PowReal(NaN+xϵ₁+xϵ₂, y) = NaN+NaNϵ₁+NaNϵ₂+NaNϵ₁ϵ₂
{d: Number{Real: math.NaN(), E1mag: 0, E2mag: 0}, p: 2, want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 0, E2mag: 0}, p: 3, want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 1, E2mag: 1}, p: 2, want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 1, E2mag: 1}, p: 3, want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 2, E2mag: 2}, p: 2, want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 2, E2mag: 2}, p: 3, want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 1, E2mag: 2}, p: 2, want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: math.NaN(), E1mag: 1, E2mag: 2}, p: 3, want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
// PowReal(x, NaN) = NaN+NaNϵ₁+NaNϵ₂+NaNϵ₁ϵ₂
{d: Number{Real: 0, E1mag: 0, E2mag: 0}, p: math.NaN(), want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 2, E1mag: 0, E2mag: 0}, p: math.NaN(), want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 3, E1mag: 0, E2mag: 0}, p: math.NaN(), want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 0, E1mag: 1, E2mag: 1}, p: math.NaN(), want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 2, E1mag: 1, E2mag: 1}, p: math.NaN(), want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 3, E1mag: 1, E2mag: 1}, p: math.NaN(), want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 0, E1mag: 2, E2mag: 2}, p: math.NaN(), want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 2, E1mag: 2, E2mag: 2}, p: math.NaN(), want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 3, E1mag: 2, E2mag: 2}, p: math.NaN(), want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
// Handled by math.Pow tests:
//
// Pow(±0, y) = ±Inf for y an odd integer < 0
// Pow(±0, -Inf) = +Inf
// Pow(±0, +Inf) = +0
// Pow(±0, y) = +Inf for finite y < 0 and not an odd integer
// Pow(±0, y) = ±0 for y an odd integer > 0
// Pow(±0, y) = +0 for finite y > 0 and not an odd integer
// Pow(-1, ±Inf) = 1
// PowReal(x+0ϵ₁+0ϵ₂, +Inf) = +Inf+NaNϵ₁+NaNϵ₂+NaNϵ₁ϵ₂ for |x| > 1
{d: Number{Real: 2, E1mag: 0, E2mag: 0}, p: math.Inf(1), want: Number{Real: math.Inf(1), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 3, E1mag: 0, E2mag: 0}, p: math.Inf(1), want: Number{Real: math.Inf(1), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
// PowReal(x+xϵ₁+yϵ₂, +Inf) = +Inf+Infϵ₁+Infϵ₂+NaNϵ₁ϵ₂ for |x| > 1
{d: Number{Real: 2, E1mag: 1, E2mag: 1}, p: math.Inf(1), want: Number{Real: math.Inf(1), E1mag: math.Inf(1), E2mag: math.Inf(1), E1E2mag: math.NaN()}},
{d: Number{Real: 3, E1mag: 1, E2mag: 1}, p: math.Inf(1), want: Number{Real: math.Inf(1), E1mag: math.Inf(1), E2mag: math.Inf(1), E1E2mag: math.NaN()}},
{d: Number{Real: 2, E1mag: 2, E2mag: 2}, p: math.Inf(1), want: Number{Real: math.Inf(1), E1mag: math.Inf(1), E2mag: math.Inf(1), E1E2mag: math.NaN()}},
{d: Number{Real: 3, E1mag: 2, E2mag: 2}, p: math.Inf(1), want: Number{Real: math.Inf(1), E1mag: math.Inf(1), E2mag: math.Inf(1), E1E2mag: math.NaN()}},
{d: Number{Real: 3, E1mag: 2, E2mag: 3}, p: math.Inf(1), want: Number{Real: math.Inf(1), E1mag: math.Inf(1), E2mag: math.Inf(1), E1E2mag: math.NaN()}},
// PowReal(x, -Inf) = +0+NaNϵ₁+NaNϵ₂+NaNϵ₁ϵ₂ for |x| > 1
{d: Number{Real: 2, E1mag: 0, E2mag: 0}, p: math.Inf(-1), want: Number{Real: 0, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 3, E1mag: 0, E2mag: 0}, p: math.Inf(-1), want: Number{Real: 0, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 2, E1mag: 1, E2mag: 1}, p: math.Inf(-1), want: Number{Real: 0, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 3, E1mag: 1, E2mag: 1}, p: math.Inf(-1), want: Number{Real: 0, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 2, E1mag: 2, E2mag: 2}, p: math.Inf(-1), want: Number{Real: 0, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 3, E1mag: 2, E2mag: 2}, p: math.Inf(-1), want: Number{Real: 0, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
// PowReal(x+yϵ₁+zϵ₂, +Inf) = +0+NaNϵ₁+NaNϵ₂+NaNϵ₁ϵ₂ for |x| < 1
{d: Number{Real: 0.1, E1mag: 0, E2mag: 0}, p: math.Inf(1), want: Number{Real: 0, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 0.1, E1mag: 0.1, E2mag: 0.1}, p: math.Inf(1), want: Number{Real: 0, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 0.2, E1mag: 0.2, E2mag: 0.2}, p: math.Inf(1), want: Number{Real: 0, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 0.5, E1mag: 0.3, E2mag: 0.5}, p: math.Inf(1), want: Number{Real: 0, E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
// PowReal(x+0ϵ₁+0ϵ₂, -Inf) = +Inf+NaNϵ₁+NaNϵ₂+NaNϵ₁ϵ₂ for |x| < 1
{d: Number{Real: 0.1, E1mag: 0, E2mag: 0}, p: math.Inf(-1), want: Number{Real: math.Inf(1), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: 0.2, E1mag: 0, E2mag: 0}, p: math.Inf(-1), want: Number{Real: math.Inf(1), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
// PowReal(x, -Inf) = +Inf-Infϵ₁-Infϵ₂+NaNϵ₁ϵ₂ for |x| < 1
{d: Number{Real: 0.1, E1mag: 0.1, E2mag: 0.1}, p: math.Inf(-1), want: Number{Real: math.Inf(1), E1mag: math.Inf(-1), E2mag: math.Inf(-1), E1E2mag: math.NaN()}},
{d: Number{Real: 0.2, E1mag: 0.1, E2mag: 0.1}, p: math.Inf(-1), want: Number{Real: math.Inf(1), E1mag: math.Inf(-1), E2mag: math.Inf(-1), E1E2mag: math.NaN()}},
{d: Number{Real: 0.1, E1mag: 0.2, E2mag: 0.2}, p: math.Inf(-1), want: Number{Real: math.Inf(1), E1mag: math.Inf(-1), E2mag: math.Inf(-1), E1E2mag: math.NaN()}},
{d: Number{Real: 0.2, E1mag: 0.3, E2mag: 0.2}, p: math.Inf(-1), want: Number{Real: math.Inf(1), E1mag: math.Inf(-1), E2mag: math.Inf(-1), E1E2mag: math.NaN()}},
{d: Number{Real: 0.1, E1mag: 1, E2mag: 1}, p: math.Inf(-1), want: Number{Real: math.Inf(1), E1mag: math.Inf(-1), E2mag: math.Inf(-1), E1E2mag: math.NaN()}},
{d: Number{Real: 0.2, E1mag: 1, E2mag: 1}, p: math.Inf(-1), want: Number{Real: math.Inf(1), E1mag: math.Inf(-1), E2mag: math.Inf(-1), E1E2mag: math.NaN()}},
{d: Number{Real: 0.1, E1mag: 2, E2mag: 2}, p: math.Inf(-1), want: Number{Real: math.Inf(1), E1mag: math.Inf(-1), E2mag: math.Inf(-1), E1E2mag: math.NaN()}},
{d: Number{Real: 0.2, E1mag: 2, E2mag: 2}, p: math.Inf(-1), want: Number{Real: math.Inf(1), E1mag: math.Inf(-1), E2mag: math.Inf(-1), E1E2mag: math.NaN()}},
// Handled by math.Pow tests:
//
// Pow(+Inf, y) = +Inf for y > 0
// Pow(+Inf, y) = +0 for y < 0
// Pow(-Inf, y) = Pow(-0, -y)
// PowReal(x, y) = NaN+NaNϵ₁+NaNϵ₂+NaNϵ₁ϵ₂ for finite x < 0 and finite non-integer y
{d: Number{Real: -1, E1mag: -1, E2mag: -1}, p: 0.5, want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: -1, E1mag: 2, E2mag: 2}, p: 0.5, want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
{d: Number{Real: -1, E1mag: -1, E2mag: 2}, p: 0.5, want: Number{Real: math.NaN(), E1mag: math.NaN(), E2mag: math.NaN(), E1E2mag: math.NaN()}},
}
func TestPowReal(t *testing.T) {
t.Parallel()
const tol = 1e-15
for _, test := range powRealTests {
got := PowReal(test.d, test.p)
if !sameHyperdual(got, test.want, tol) {
t.Errorf("unexpected PowReal(%v, %v): got:%v want:%v", test.d, test.p, got, test.want)
}
}
}
func sameHyperdual(a, b Number, tol float64) bool {
return same(a.Real, b.Real, tol) && same(a.E1mag, b.E1mag, tol) &&
same(a.E2mag, b.E2mag, tol) && same(a.E1E2mag, b.E1E2mag, tol)
}
func same(a, b, tol float64) bool {
return (math.IsNaN(a) && math.IsNaN(b)) ||
(scalar.EqualWithinAbsOrRel(a, b, tol, tol) && math.Float64bits(a)&(1<<63) == math.Float64bits(b)&(1<<63))
}