v/vlib/math/fractions/approximations_test.v

// Copyright (c) 2019-2024 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
import math.fractions
import math

fn test_half() {
	float_val := 0.5
	fract_val := fractions.approximate(float_val)
	assert fract_val == fractions.fraction(1, 2)
}

fn test_third() {
	float_val := 1.0 / 3.0
	fract_val := fractions.approximate(float_val)
	assert fract_val == fractions.fraction(1, 3)
}

fn test_minus_one_twelfth() {
	float_val := -1.0 / 12.0
	fract_val := fractions.approximate(float_val)
	assert fract_val == fractions.fraction(-1, 12)
}

fn test_zero() {
	float_val := 0.0
	println('Pre')
	fract_val := fractions.approximate(float_val)
	println('Post')
	assert fract_val == fractions.fraction(0, 1)
}

fn test_minus_one() {
	float_val := -1.0
	fract_val := fractions.approximate(float_val)
	assert fract_val == fractions.fraction(-1, 1)
}

fn test_thirty_three() {
	float_val := 33.0
	fract_val := fractions.approximate(float_val)
	assert fract_val == fractions.fraction(33, 1)
}

fn test_millionth() {
	float_val := 1.0 / 1000000.0
	fract_val := fractions.approximate(float_val)
	assert fract_val == fractions.fraction(1, 1000000)
}

fn test_minus_27_by_57() {
	float_val := -27.0 / 57.0
	fract_val := fractions.approximate(float_val)
	assert fract_val == fractions.fraction(-27, 57)
}

fn test_29_by_104() {
	float_val := 29.0 / 104.0
	fract_val := fractions.approximate(float_val)
	assert fract_val == fractions.fraction(29, 104)
}

fn test_140710_232() {
	float_val := 140710.232
	fract_val := fractions.approximate(float_val)
	// Approximation will match perfectly for upto 3 places after the decimal
	// The result will be within default_eps of original value
	assert fract_val.f64() == float_val
}

fn test_pi_1_digit() {
	assert fractions.approximate_with_eps(math.pi, 5.0e-2) == fractions.fraction(22, 7)
}

fn test_pi_2_digits() {
	assert fractions.approximate_with_eps(math.pi, 5.0e-3) == fractions.fraction(22, 7)
}

fn test_pi_3_digits() {
	assert fractions.approximate_with_eps(math.pi, 5.0e-4) == fractions.fraction(333,
		106)
}

fn test_pi_4_digits() {
	assert fractions.approximate_with_eps(math.pi, 5.0e-5) == fractions.fraction(355,
		113)
}

fn test_pi_5_digits() {
	assert fractions.approximate_with_eps(math.pi, 5.0e-6) == fractions.fraction(355,
		113)
}

fn test_pi_6_digits() {
	assert fractions.approximate_with_eps(math.pi, 5.0e-7) == fractions.fraction(355,
		113)
}

fn test_pi_7_digits() {
	assert fractions.approximate_with_eps(math.pi, 5.0e-8) == fractions.fraction(103993,
		33102)
}

fn test_pi_8_digits() {
	assert fractions.approximate_with_eps(math.pi, 5.0e-9) == fractions.fraction(103993,
		33102)
}

fn test_pi_9_digits() {
	assert fractions.approximate_with_eps(math.pi, 5.0e-10) == fractions.fraction(104348,
		33215)
}

fn test_pi_10_digits() {
	assert fractions.approximate_with_eps(math.pi, 5.0e-11) == fractions.fraction(312689,
		99532)
}

fn test_pi_11_digits() {
	assert fractions.approximate_with_eps(math.pi, 5.0e-12) == fractions.fraction(1146408,
		364913)
}

fn test_pi_12_digits() {
	assert fractions.approximate_with_eps(math.pi, 5.0e-13) == fractions.fraction(4272943,
		1360120)
}

fn test_phi_1_digit() {
	assert fractions.approximate_with_eps(math.phi, 5.0e-2) == fractions.fraction(5, 3)
}

fn test_phi_2_digits() {
	assert fractions.approximate_with_eps(math.phi, 5.0e-3) == fractions.fraction(21,
		13)
}

fn test_phi_3_digits() {
	assert fractions.approximate_with_eps(math.phi, 5.0e-4) == fractions.fraction(55,
		34)
}

fn test_phi_4_digits() {
	assert fractions.approximate_with_eps(math.phi, 5.0e-5) == fractions.fraction(233,
		144)
}

fn test_phi_5_digits() {
	assert fractions.approximate_with_eps(math.phi, 5.0e-6) == fractions.fraction(610,
		377)
}

fn test_phi_6_digits() {
	assert fractions.approximate_with_eps(math.phi, 5.0e-7) == fractions.fraction(1597,
		987)
}

fn test_phi_7_digits() {
	assert fractions.approximate_with_eps(math.phi, 5.0e-8) == fractions.fraction(6765,
		4181)
}

fn test_phi_8_digits() {
	assert fractions.approximate_with_eps(math.phi, 5.0e-9) == fractions.fraction(17711,
		10946)
}

fn test_phi_9_digits() {
	assert fractions.approximate_with_eps(math.phi, 5.0e-10) == fractions.fraction(75025,
		46368)
}

fn test_phi_10_digits() {
	assert fractions.approximate_with_eps(math.phi, 5.0e-11) == fractions.fraction(196418,
		121393)
}

fn test_phi_11_digits() {
	assert fractions.approximate_with_eps(math.phi, 5.0e-12) == fractions.fraction(514229,
		317811)
}

fn test_phi_12_digits() {
	assert fractions.approximate_with_eps(math.phi, 5.0e-13) == fractions.fraction(2178309,
		1346269)
}