math/test/test_autodiff_2.cpp
pulver 95defb67df
Add make_ftuple(), digamma(), lgamma(), tgamma(), doc/test updates. (#218)
Improve tests and coverage. C++11/14 support. (@kedarbhat)
2019-06-25 17:31:48 -07:00

513 lines
21 KiB
C++

// Copyright Matthew Pulver 2018 - 2019.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// https://www.boost.org/LICENSE_1_0.txt)
#include "test_autodiff.hpp"
BOOST_AUTO_TEST_SUITE(test_autodiff_2)
BOOST_AUTO_TEST_CASE_TEMPLATE(one_over_one_plus_x_squared, T, all_float_types) {
constexpr std::size_t m = 4;
const T cx(1);
auto f = make_fvar<T, m>(cx);
// f = 1 / ((f *= f) += 1);
f *= f;
f += T(1);
f = f.inverse();
BOOST_CHECK_EQUAL(f.derivative(0u), 0.5);
BOOST_CHECK_EQUAL(f.derivative(1u), -0.5);
BOOST_CHECK_EQUAL(f.derivative(2u), 0.5);
BOOST_CHECK_EQUAL(f.derivative(3u), 0);
BOOST_CHECK_EQUAL(f.derivative(4u), -3);
}
BOOST_AUTO_TEST_CASE_TEMPLATE(exp_test, T, all_float_types) {
using std::exp;
constexpr std::size_t m = 4;
const T cx = 2.0;
const auto x = make_fvar<T, m>(cx);
auto y = exp(x);
for (auto i : boost::irange(m + 1)) {
// std::cout.precision(100);
// std::cout << "y.derivative("<<i<<") = " << y.derivative(i) << ",
// std::exp(cx) = " << std::exp(cx) << std::endl;
BOOST_CHECK_CLOSE_FRACTION(y.derivative(i), exp(cx),
std::numeric_limits<T>::epsilon());
}
}
BOOST_AUTO_TEST_CASE_TEMPLATE(pow, T, bin_float_types) {
const T eps = 201 * std::numeric_limits<T>::epsilon(); // percent
using std::log;
using std::pow;
constexpr std::size_t m = 5;
constexpr std::size_t n = 4;
const T cx = 2.0;
const T cy = 3.0;
const auto x = make_fvar<T, m>(cx);
const auto y = make_fvar<T, m, n>(cy);
auto z0 = pow(x, cy);
BOOST_CHECK_EQUAL(z0.derivative(0u), pow(cx, cy));
BOOST_CHECK_EQUAL(z0.derivative(1u), cy * pow(cx, cy - 1));
BOOST_CHECK_EQUAL(z0.derivative(2u), cy * (cy - 1) * pow(cx, cy - 2));
BOOST_CHECK_EQUAL(z0.derivative(3u),
cy * (cy - 1) * (cy - 2) * pow(cx, cy - 3));
BOOST_CHECK_EQUAL(z0.derivative(4u), 0u);
BOOST_CHECK_EQUAL(z0.derivative(5u), 0u);
auto z1 = pow(cx, y);
BOOST_CHECK_CLOSE(z1.derivative(0u, 0u), pow(cx, cy), eps);
for (auto j : boost::irange(std::size_t(1), n + 1)) {
BOOST_CHECK_CLOSE(z1.derivative(0u, j), pow(log(cx), j) * pow(cx, cy), eps);
}
for (auto i : boost::irange(std::size_t(1), m + 1)) {
for (auto j : boost::irange(n + 1)) {
BOOST_CHECK_EQUAL(z1.derivative(i, j), 0);
}
}
const auto z2 = pow(x, y);
for (auto j : boost::irange(n + 1)) {
BOOST_CHECK_CLOSE(z2.derivative(0u, j), pow(cx, cy) * pow(log(cx), j), eps);
}
for (auto j : boost::irange(n + 1)) {
BOOST_CHECK_CLOSE(z2.derivative(1u, j),
pow(cx, cy - 1) * pow(log(cx), static_cast<int>(j) - 1) *
(cy * log(cx) + j),
eps);
}
BOOST_CHECK_CLOSE(z2.derivative(2u, 0u), pow(cx, cy - 2) * cy * (cy - 1),
eps);
BOOST_CHECK_CLOSE(z2.derivative(2u, 1u),
pow(cx, cy - 2) * (cy * (cy - 1) * log(cx) + 2 * cy - 1),
eps);
for (auto j : boost::irange(std::size_t(2u), n + 1)) {
BOOST_CHECK_CLOSE(z2.derivative(2u, j),
pow(cx, cy - 2) * pow(log(cx), j - 2) *
(j * (2 * cy - 1) * log(cx) + (j - 1) * j +
(cy - 1) * cy * pow(log(cx), 2)),
eps);
}
BOOST_CHECK_CLOSE(z2.derivative(2u, 4u),
pow(cx, cy - 2) * pow(log(cx), 2) *
(4 * (2 * cy - 1) * log(cx) + (4 - 1) * 4 +
(cy - 1) * cy * pow(log(cx), 2)),
eps);
}
// TODO Tests around x=0 or y=0: pow(x,y)
BOOST_AUTO_TEST_CASE_TEMPLATE(pow2, T, bin_float_types) {
const T eps = 4000 * std::numeric_limits<T>::epsilon(); // percent
using std::pow;
constexpr std::size_t m = 5;
constexpr std::size_t n = 5;
const T cx = 2;
const T cy = 5 / 2.0;
const auto x = make_fvar<T, m>(cx);
const auto y = make_fvar<T, 0, n>(cy);
const auto z = pow(x, y);
using namespace boost::math::constants;
// Mathematica: Export["pow.csv", Flatten@Table[ Simplify@D[x^y,{x,i},{y,j}]
// /. {x->2, y->5/2},
// { i, 0, 5 }, { j, 0, 5 } ] ]
// sed -rf pow.sed < pow.csv
// with pow.sed script:
// s/Log\[2\]\^([0-9]+)/pow(ln_two<T>(),\1)/g
// s/Log\[2\]/ln_two<T>()/g
// s/Sqrt\[2\]/root_two<T>()/g
// s/[0-9]\/[0-9]+/\0.0/g
// s/^"/static_cast<T>(/
// s/"$/),/
const T mathematica[]{
static_cast<T>(4 * root_two<T>()),
static_cast<T>(4 * root_two<T>() * ln_two<T>()),
static_cast<T>(4 * root_two<T>() * pow(ln_two<T>(), 2)),
static_cast<T>(4 * root_two<T>() * pow(ln_two<T>(), 3)),
static_cast<T>(4 * root_two<T>() * pow(ln_two<T>(), 4)),
static_cast<T>(4 * root_two<T>() * pow(ln_two<T>(), 5)),
static_cast<T>(5 * root_two<T>()),
static_cast<T>(2 * root_two<T>() * (1 + (5 * ln_two<T>()) / 2)),
static_cast<T>(2 * root_two<T>() * ln_two<T>() *
(2 + (5 * ln_two<T>()) / 2)),
static_cast<T>(2 * root_two<T>() * pow(ln_two<T>(), 2) *
(3 + (5 * ln_two<T>()) / 2)),
static_cast<T>(2 * root_two<T>() * pow(ln_two<T>(), 3) *
(4 + (5 * ln_two<T>()) / 2)),
static_cast<T>(2 * root_two<T>() * pow(ln_two<T>(), 4) *
(5 + (5 * ln_two<T>()) / 2)),
static_cast<T>(15 / (2 * root_two<T>())),
static_cast<T>(root_two<T>() * (4 + (15 * ln_two<T>()) / 4)),
static_cast<T>(root_two<T>() *
(2 + 8 * ln_two<T>() + (15 * pow(ln_two<T>(), 2)) / 4)),
static_cast<T>(root_two<T>() * ln_two<T>() *
(6 + 12 * ln_two<T>() + (15 * pow(ln_two<T>(), 2)) / 4)),
static_cast<T>(root_two<T>() * pow(ln_two<T>(), 2) *
(12 + 16 * ln_two<T>() + (15 * pow(ln_two<T>(), 2)) / 4)),
static_cast<T>(root_two<T>() * pow(ln_two<T>(), 3) *
(20 + 20 * ln_two<T>() + (15 * pow(ln_two<T>(), 2)) / 4)),
static_cast<T>(15 / (8 * root_two<T>())),
static_cast<T>((23 / 4.0 + (15 * ln_two<T>()) / 8) / root_two<T>()),
static_cast<T>(
(9 + (23 * ln_two<T>()) / 2 + (15 * pow(ln_two<T>(), 2)) / 8) /
root_two<T>()),
static_cast<T>((6 + 27 * ln_two<T>() + (69 * pow(ln_two<T>(), 2)) / 4 +
(15 * pow(ln_two<T>(), 3)) / 8) /
root_two<T>()),
static_cast<T>(
(ln_two<T>() * (24 + 54 * ln_two<T>() + 23 * pow(ln_two<T>(), 2) +
(15 * pow(ln_two<T>(), 3)) / 8)) /
root_two<T>()),
static_cast<T>((pow(ln_two<T>(), 2) *
(60 + 90 * ln_two<T>() + (115 * pow(ln_two<T>(), 2)) / 4 +
(15 * pow(ln_two<T>(), 3)) / 8)) /
root_two<T>()),
static_cast<T>(-15 / (32 * root_two<T>())),
static_cast<T>((-1 - (15 * ln_two<T>()) / 16) / (2 * root_two<T>())),
static_cast<T>((7 - 2 * ln_two<T>() - (15 * pow(ln_two<T>(), 2)) / 16) /
(2 * root_two<T>())),
static_cast<T>((24 + 21 * ln_two<T>() - 3 * pow(ln_two<T>(), 2) -
(15 * pow(ln_two<T>(), 3)) / 16) /
(2 * root_two<T>())),
static_cast<T>((24 + 96 * ln_two<T>() + 42 * pow(ln_two<T>(), 2) -
4 * pow(ln_two<T>(), 3) -
(15 * pow(ln_two<T>(), 4)) / 16) /
(2 * root_two<T>())),
static_cast<T>(
(ln_two<T>() *
(120 + 240 * ln_two<T>() + 70 * pow(ln_two<T>(), 2) -
5 * pow(ln_two<T>(), 3) - (15 * pow(ln_two<T>(), 4)) / 16)) /
(2 * root_two<T>())),
static_cast<T>(45 / (128 * root_two<T>())),
static_cast<T>((9 / 16.0 + (45 * ln_two<T>()) / 32) /
(4 * root_two<T>())),
static_cast<T>((-25 / 2.0 + (9 * ln_two<T>()) / 8 +
(45 * pow(ln_two<T>(), 2)) / 32) /
(4 * root_two<T>())),
static_cast<T>((-15 - (75 * ln_two<T>()) / 2 +
(27 * pow(ln_two<T>(), 2)) / 16 +
(45 * pow(ln_two<T>(), 3)) / 32) /
(4 * root_two<T>())),
static_cast<T>((60 - 60 * ln_two<T>() - 75 * pow(ln_two<T>(), 2) +
(9 * pow(ln_two<T>(), 3)) / 4 +
(45 * pow(ln_two<T>(), 4)) / 32) /
(4 * root_two<T>())),
static_cast<T>((120 + 300 * ln_two<T>() - 150 * pow(ln_two<T>(), 2) -
125 * pow(ln_two<T>(), 3) +
(45 * pow(ln_two<T>(), 4)) / 16 +
(45 * pow(ln_two<T>(), 5)) / 32) /
(4 * root_two<T>()))};
std::size_t k = 0;
for (auto i : boost::irange(m + 1)) {
for (auto j : boost::irange(n + 1)) {
BOOST_CHECK_CLOSE(z.derivative(i, j), mathematica[k++], eps);
}
}
}
BOOST_AUTO_TEST_CASE_TEMPLATE(sqrt_test, T, all_float_types) {
using std::pow;
using std::sqrt;
constexpr std::size_t m = 5;
const T cx = 4.0;
auto x = make_fvar<T, m>(cx);
auto y = sqrt(x);
BOOST_CHECK_CLOSE_FRACTION(y.derivative(0u), sqrt(cx),
std::numeric_limits<T>::epsilon());
BOOST_CHECK_CLOSE_FRACTION(y.derivative(1u), 0.5 * pow(cx, -0.5),
std::numeric_limits<T>::epsilon());
BOOST_CHECK_CLOSE_FRACTION(y.derivative(2u), -0.5 * 0.5 * pow(cx, -1.5),
std::numeric_limits<T>::epsilon());
BOOST_CHECK_CLOSE_FRACTION(y.derivative(3u), 0.5 * 0.5 * 1.5 * pow(cx, -2.5),
std::numeric_limits<T>::epsilon());
BOOST_CHECK_CLOSE_FRACTION(y.derivative(4u),
-0.5 * 0.5 * 1.5 * 2.5 * pow(cx, -3.5),
std::numeric_limits<T>::epsilon());
BOOST_CHECK_CLOSE_FRACTION(y.derivative(5u),
0.5 * 0.5 * 1.5 * 2.5 * 3.5 * pow(cx, -4.5),
std::numeric_limits<T>::epsilon());
x = make_fvar<T, m>(0);
y = sqrt(x);
// std::cout << "sqrt(0) = " << y << std::endl; // (0,inf,-inf,inf,-inf,inf)
BOOST_CHECK_EQUAL(y.derivative(0u), 0);
for (auto i : boost::irange(std::size_t(1), m + 1)) {
BOOST_CHECK_EQUAL(y.derivative(i), (i % 2 == 1 ? 1 : -1) *
std::numeric_limits<T>::infinity());
}
}
BOOST_AUTO_TEST_CASE_TEMPLATE(log_test, T, all_float_types) {
using std::log;
using std::pow;
constexpr std::size_t m = 5;
const T cx = 2.0;
auto x = make_fvar<T, m>(cx);
auto y = log(x);
BOOST_CHECK_CLOSE_FRACTION(y.derivative(0u), log(cx),
std::numeric_limits<T>::epsilon());
BOOST_CHECK_CLOSE_FRACTION(y.derivative(1u), 1 / cx,
std::numeric_limits<T>::epsilon());
BOOST_CHECK_CLOSE_FRACTION(y.derivative(2u), -1 / pow(cx, 2),
std::numeric_limits<T>::epsilon());
BOOST_CHECK_CLOSE_FRACTION(y.derivative(3u), 2 / pow(cx, 3),
std::numeric_limits<T>::epsilon());
BOOST_CHECK_CLOSE_FRACTION(y.derivative(4u), -6 / pow(cx, 4),
std::numeric_limits<T>::epsilon());
BOOST_CHECK_CLOSE_FRACTION(y.derivative(5u), 24 / pow(cx, 5),
std::numeric_limits<T>::epsilon());
x = make_fvar<T, m>(0);
y = log(x);
// std::cout << "log(0) = " << y << std::endl; // log(0) =
// depth(1)(-inf,inf,-inf,inf,-inf,inf)
for (auto i : boost::irange(m + 1)) {
BOOST_CHECK_EQUAL(y.derivative(i), (i % 2 == 1 ? 1 : -1) *
std::numeric_limits<T>::infinity());
}
}
BOOST_AUTO_TEST_CASE_TEMPLATE(ylogx, T, all_float_types) {
using std::log;
using std::pow;
const T eps = 100 * std::numeric_limits<T>::epsilon(); // percent
constexpr std::size_t m = 5;
constexpr std::size_t n = 4;
const T cx = 2.0;
const T cy = 3.0;
const auto x = make_fvar<T, m>(cx);
const auto y = make_fvar<T, m, n>(cy);
auto z = y * log(x);
BOOST_CHECK_EQUAL(z.derivative(0u, 0u), cy * log(cx));
BOOST_CHECK_EQUAL(z.derivative(0u, 1u), log(cx));
BOOST_CHECK_EQUAL(z.derivative(0u, 2u), 0);
BOOST_CHECK_EQUAL(z.derivative(0u, 3u), 0);
BOOST_CHECK_EQUAL(z.derivative(0u, 4u), 0);
for (auto i : boost::irange(1u, static_cast<unsigned>(m + 1))) {
BOOST_CHECK_CLOSE(z.derivative(i, 0u),
pow(-1, i - 1) * boost::math::factorial<T>(i - 1) * cy /
pow(cx, i),
eps);
BOOST_CHECK_CLOSE(
z.derivative(i, 1u),
pow(-1, i - 1) * boost::math::factorial<T>(i - 1) / pow(cx, i), eps);
for (auto j : boost::irange(std::size_t(2), n + 1)) {
BOOST_CHECK_EQUAL(z.derivative(i, j), 0u);
}
}
auto z1 = exp(z);
// RHS is confirmed by
// https://www.wolframalpha.com/input/?i=D%5Bx%5Ey,%7Bx,2%7D,%7By,4%7D%5D+%2F.+%7Bx-%3E2.0,+y-%3E3.0%7D
BOOST_CHECK_CLOSE(z1.derivative(2u, 4u),
pow(cx, cy - 2) * pow(log(cx), 2) *
(4 * (2 * cy - 1) * log(cx) + (4 - 1) * 4 +
(cy - 1) * cy * pow(log(cx), 2)),
eps);
}
BOOST_AUTO_TEST_CASE_TEMPLATE(frexp_test, T, all_float_types) {
using std::exp2;
using std::frexp;
constexpr std::size_t m = 3;
const T cx = 3.5;
const auto x = make_fvar<T, m>(cx);
int exp, testexp;
auto y = frexp(x, &exp);
BOOST_CHECK_EQUAL(y.derivative(0u), frexp(cx, &testexp));
BOOST_CHECK_EQUAL(exp, testexp);
BOOST_CHECK_EQUAL(y.derivative(1u), exp2(-exp));
BOOST_CHECK_EQUAL(y.derivative(2u), 0);
BOOST_CHECK_EQUAL(y.derivative(3u), 0);
}
BOOST_AUTO_TEST_CASE_TEMPLATE(ldexp_test, T, all_float_types) {
BOOST_MATH_STD_USING
using boost::multiprecision::ldexp;
constexpr auto m = 3u;
const T cx = 3.5;
const auto x = make_fvar<T, m>(cx);
constexpr auto exponent = 3;
auto y = ldexp(x, exponent);
BOOST_CHECK_EQUAL(y.derivative(0u), ldexp(cx, exponent));
BOOST_CHECK_EQUAL(y.derivative(1u), exp2(exponent));
BOOST_CHECK_EQUAL(y.derivative(2u), 0);
BOOST_CHECK_EQUAL(y.derivative(3u), 0);
}
BOOST_AUTO_TEST_CASE_TEMPLATE(cos_and_sin, T, bin_float_types) {
using std::cos;
using std::sin;
const T eps = 200 * std::numeric_limits<T>::epsilon(); // percent
constexpr std::size_t m = 5;
const T cx = boost::math::constants::third_pi<T>();
const auto x = make_fvar<T, m>(cx);
auto cos5 = cos(x);
BOOST_CHECK_CLOSE(cos5.derivative(0u), cos(cx), eps);
BOOST_CHECK_CLOSE(cos5.derivative(1u), -sin(cx), eps);
BOOST_CHECK_CLOSE(cos5.derivative(2u), -cos(cx), eps);
BOOST_CHECK_CLOSE(cos5.derivative(3u), sin(cx), eps);
BOOST_CHECK_CLOSE(cos5.derivative(4u), cos(cx), eps);
BOOST_CHECK_CLOSE(cos5.derivative(5u), -sin(cx), eps);
auto sin5 = sin(x);
BOOST_CHECK_CLOSE(sin5.derivative(0u), sin(cx), eps);
BOOST_CHECK_CLOSE(sin5.derivative(1u), cos(cx), eps);
BOOST_CHECK_CLOSE(sin5.derivative(2u), -sin(cx), eps);
BOOST_CHECK_CLOSE(sin5.derivative(3u), -cos(cx), eps);
BOOST_CHECK_CLOSE(sin5.derivative(4u), sin(cx), eps);
BOOST_CHECK_CLOSE(sin5.derivative(5u), cos(cx), eps);
// Test Order = 0 for codecov
auto cos0 = cos(make_fvar<T, 0>(cx));
BOOST_CHECK_CLOSE(cos0.derivative(0u), cos(cx), eps);
auto sin0 = sin(make_fvar<T, 0>(cx));
BOOST_CHECK_CLOSE(sin0.derivative(0u), sin(cx), eps);
}
BOOST_AUTO_TEST_CASE_TEMPLATE(acos_test, T, bin_float_types) {
const T eps = 300 * std::numeric_limits<T>::epsilon(); // percent
using std::acos;
using std::pow;
using std::sqrt;
constexpr std::size_t m = 5;
const T cx = 0.5;
auto x = make_fvar<T, m>(cx);
auto y = acos(x);
BOOST_CHECK_CLOSE(y.derivative(0u), acos(cx), eps);
BOOST_CHECK_CLOSE(y.derivative(1u), -1 / sqrt(1 - cx * cx), eps);
BOOST_CHECK_CLOSE(y.derivative(2u), -cx / pow(1 - cx * cx, 1.5), eps);
BOOST_CHECK_CLOSE(y.derivative(3u),
-(2 * cx * cx + 1) / pow(1 - cx * cx, 2.5), eps);
BOOST_CHECK_CLOSE(y.derivative(4u),
-3 * cx * (2 * cx * cx + 3) / pow(1 - cx * cx, 3.5), eps);
BOOST_CHECK_CLOSE(y.derivative(5u),
-(24 * (cx * cx + 3) * cx * cx + 9) / pow(1 - cx * cx, 4.5),
eps);
}
BOOST_AUTO_TEST_CASE_TEMPLATE(acosh_test, T, bin_float_types) {
const T eps = 300 * std::numeric_limits<T>::epsilon(); // percent
using boost::math::acosh;
constexpr std::size_t m = 5;
const T cx = 2;
auto x = make_fvar<T, m>(cx);
auto y = acosh(x);
// BOOST_CHECK_EQUAL(y.derivative(0) == acosh(cx)); // FAILS! acosh(2) is
// overloaded for integral types
BOOST_CHECK_CLOSE(y.derivative(0u), acosh(static_cast<T>(x)), eps);
BOOST_CHECK_CLOSE(y.derivative(1u),
1 / boost::math::constants::root_three<T>(), eps);
BOOST_CHECK_CLOSE(y.derivative(2u),
-2 / (3 * boost::math::constants::root_three<T>()), eps);
BOOST_CHECK_CLOSE(y.derivative(3u),
1 / boost::math::constants::root_three<T>(), eps);
BOOST_CHECK_CLOSE(y.derivative(4u),
-22 / (9 * boost::math::constants::root_three<T>()), eps);
BOOST_CHECK_CLOSE(y.derivative(5u),
227 / (27 * boost::math::constants::root_three<T>()),
2 * eps);
}
BOOST_AUTO_TEST_CASE_TEMPLATE(asin_test, T, bin_float_types) {
const T eps = 300 * std::numeric_limits<T>::epsilon(); // percent
using std::asin;
using std::pow;
using std::sqrt;
constexpr std::size_t m = 5;
const T cx = 0.5;
auto x = make_fvar<T, m>(cx);
auto y = asin(x);
BOOST_CHECK_CLOSE(y.derivative(0u), asin(static_cast<T>(x)), eps);
BOOST_CHECK_CLOSE(y.derivative(1u), 1 / sqrt(1 - cx * cx), eps);
BOOST_CHECK_CLOSE(y.derivative(2u), cx / pow(1 - cx * cx, 1.5), eps);
BOOST_CHECK_CLOSE(y.derivative(3u), (2 * cx * cx + 1) / pow(1 - cx * cx, 2.5),
eps);
BOOST_CHECK_CLOSE(y.derivative(4u),
3 * cx * (2 * cx * cx + 3) / pow(1 - cx * cx, 3.5), eps);
BOOST_CHECK_CLOSE(y.derivative(5u),
(24 * (cx * cx + 3) * cx * cx + 9) / pow(1 - cx * cx, 4.5),
eps);
}
BOOST_AUTO_TEST_CASE_TEMPLATE(asin_infinity, T, all_float_types) {
const T eps = 100 * std::numeric_limits<T>::epsilon(); // percent
constexpr std::size_t m = 5;
auto x = make_fvar<T, m>(1);
auto y = asin(x);
// std::cout << "asin(1) = " << y << std::endl; //
// depth(1)(1.5707963267949,inf,inf,-nan,-nan,-nan)
BOOST_CHECK_CLOSE(y.derivative(0u), boost::math::constants::half_pi<T>(),
eps); // MacOS is not exact
BOOST_CHECK_EQUAL(y.derivative(1u), std::numeric_limits<T>::infinity());
}
BOOST_AUTO_TEST_CASE_TEMPLATE(asin_derivative, T, bin_float_types) {
const T eps = 300 * std::numeric_limits<T>::epsilon(); // percent
using std::pow;
using std::sqrt;
constexpr std::size_t m = 4;
const T cx(0.5);
auto x = make_fvar<T, m>(cx);
auto y = T(1) - x * x;
BOOST_CHECK_EQUAL(y.derivative(0u), 1 - cx * cx);
BOOST_CHECK_EQUAL(y.derivative(1u), -2 * cx);
BOOST_CHECK_EQUAL(y.derivative(2u), -2);
BOOST_CHECK_EQUAL(y.derivative(3u), 0);
BOOST_CHECK_EQUAL(y.derivative(4u), 0);
y = sqrt(y);
BOOST_CHECK_EQUAL(y.derivative(0u), sqrt(1 - cx * cx));
BOOST_CHECK_CLOSE(y.derivative(1u), -cx / sqrt(1 - cx * cx), eps);
BOOST_CHECK_CLOSE(y.derivative(2u), -1 / pow(1 - cx * cx, 1.5), eps);
BOOST_CHECK_CLOSE(y.derivative(3u), -3 * cx / pow(1 - cx * cx, 2.5), eps);
BOOST_CHECK_CLOSE(y.derivative(4u),
-(12 * cx * cx + 3) / pow(1 - cx * cx, 3.5), eps);
y = y.inverse(); // asin'(x) = 1 / sqrt(1-x*x).
BOOST_CHECK_CLOSE(y.derivative(0u), 1 / sqrt(1 - cx * cx), eps);
BOOST_CHECK_CLOSE(y.derivative(1u), cx / pow(1 - cx * cx, 1.5), eps);
BOOST_CHECK_CLOSE(y.derivative(2u), (2 * cx * cx + 1) / pow(1 - cx * cx, 2.5),
eps);
BOOST_CHECK_CLOSE(y.derivative(3u),
3 * cx * (2 * cx * cx + 3) / pow(1 - cx * cx, 3.5), eps);
BOOST_CHECK_CLOSE(y.derivative(4u),
(24 * (cx * cx + 3) * cx * cx + 9) / pow(1 - cx * cx, 4.5),
eps);
}
BOOST_AUTO_TEST_CASE_TEMPLATE(asinh_test, T, bin_float_types) {
const T eps = 300 * std::numeric_limits<T>::epsilon(); // percent
using boost::math::asinh;
constexpr std::size_t m = 5;
const T cx = 1;
auto x = make_fvar<T, m>(cx);
auto y = asinh(x);
BOOST_CHECK_CLOSE(y.derivative(0u), asinh(static_cast<T>(x)), eps);
BOOST_CHECK_CLOSE(y.derivative(1u), 1 / boost::math::constants::root_two<T>(),
eps);
BOOST_CHECK_CLOSE(y.derivative(2u),
-1 / (2 * boost::math::constants::root_two<T>()), eps);
BOOST_CHECK_CLOSE(y.derivative(3u),
1 / (4 * boost::math::constants::root_two<T>()), eps);
BOOST_CHECK_CLOSE(y.derivative(4u),
3 / (8 * boost::math::constants::root_two<T>()), eps);
BOOST_CHECK_CLOSE(y.derivative(5u),
-39 / (16 * boost::math::constants::root_two<T>()), eps);
}
BOOST_AUTO_TEST_CASE_TEMPLATE(atan2_function, T, all_float_types) {
using test_constants = test_constants_t<T>;
static constexpr auto m = test_constants::order;
test_detail::RandomSample<T> x_sampler{-2000, 2000};
test_detail::RandomSample<T> y_sampler{-2000, 2000};
for (auto i : boost::irange(test_constants::n_samples)) {
std::ignore = i;
auto x = x_sampler.next();
auto y = y_sampler.next();
auto autodiff_v = atan2(make_fvar<T, m>(x), make_fvar<T, m>(y));
auto anchor_v = atan2(x, y);
BOOST_CHECK_CLOSE(autodiff_v, anchor_v,
5000 * test_constants::pct_epsilon());
}
}
BOOST_AUTO_TEST_SUITE_END()