termdash/numbers/numbers_test.go

352 lines
7.7 KiB
Go

// Copyright 2019 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package numbers
import (
"fmt"
"math"
"testing"
)
func TestRoundToNonZeroPlaces(t *testing.T) {
tests := []struct {
float float64
places int
wantFloat float64
wantPlaces int
}{
{0, 0, 0, 0},
{1.1, 0, 1.1, 0},
{-1, 1, -1, 0},
{1, 1, 1, 0},
{1, 10, 1, 0},
{1, -1, 1, 0},
{0.12345, 2, 0.13, 0},
{0.12345, -2, 0.13, 0},
{0.12345, 10, 0.12345, 0},
{0.00012345, 2, 0.00013, 3},
{0.00012345, 3, 0.000124, 3},
{0.00012345, 10, 0.00012345, 3},
{-0.00012345, 10, -0.00012345, 3},
{1.234567, 2, 1.24, 0},
{-1.234567, 2, -1.23, 0},
{1099.0000234567, 3, 1099.0000235, 4},
{-1099.0000234567, 3, -1099.0000234, 4},
}
for _, tc := range tests {
t.Run(fmt.Sprintf("%v_%v", tc.float, tc.places), func(t *testing.T) {
gotFloat, gotPlaces := RoundToNonZeroPlaces(tc.float, tc.places)
if gotFloat != tc.wantFloat || gotPlaces != tc.wantPlaces {
t.Errorf("RoundToNonZeroPlaces(%v, %d) => (%v, %v), want (%v, %v)", tc.float, tc.places, gotFloat, gotPlaces, tc.wantFloat, tc.wantPlaces)
}
})
}
}
func TestZeroBeforeDecimal(t *testing.T) {
tests := []struct {
float float64
want float64
}{
{0, 0},
{-1, 0},
{1, 0},
{1.0, 0},
{1.123, 0.123},
{-1.123, -0.123},
}
for _, tc := range tests {
t.Run(fmt.Sprint(tc.float), func(t *testing.T) {
got := zeroBeforeDecimal(tc.float)
if got != tc.want {
t.Errorf("zeroBeforeDecimal(%v) => %v, want %v", tc.float, got, tc.want)
}
})
}
}
// Copied from the math package of Go 1.10 for backwards compatibility with Go
// 1.8 where the math.Round function doesn't exist yet.
func tolerance(a, b, e float64) bool {
// Multiplying by e here can underflow denormal values to zero.
// Check a==b so that at least if a and b are small and identical
// we say they match.
if a == b {
return true
}
d := a - b
if d < 0 {
d = -d
}
// note: b is correct (expected) value, a is actual value.
// make error tolerance a fraction of b, not a.
if b != 0 {
e = e * b
if e < 0 {
e = -e
}
}
return d < e
}
func close(a, b float64) bool { return tolerance(a, b, 1e-14) }
func veryclose(a, b float64) bool { return tolerance(a, b, 4e-16) }
func soclose(a, b, e float64) bool { return tolerance(a, b, e) }
func alike(a, b float64) bool {
switch {
case math.IsNaN(a) && math.IsNaN(b):
return true
case a == b:
return math.Signbit(a) == math.Signbit(b)
}
return false
}
var round = []float64{
5,
8,
math.Copysign(0, -1),
-5,
10,
3,
5,
3,
2,
-9,
}
var vf = []float64{
4.9790119248836735e+00,
7.7388724745781045e+00,
-2.7688005719200159e-01,
-5.0106036182710749e+00,
9.6362937071984173e+00,
2.9263772392439646e+00,
5.2290834314593066e+00,
2.7279399104360102e+00,
1.8253080916808550e+00,
-8.6859247685756013e+00,
}
var vfroundSC = [][2]float64{
{0, 0},
{1.390671161567e-309, 0}, // denormal
{0.49999999999999994, 0}, // 0.5-epsilon
{0.5, 1},
{0.5000000000000001, 1}, // 0.5+epsilon
{-1.5, -2},
{-2.5, -3},
{math.NaN(), math.NaN()},
{math.Inf(1), math.Inf(1)},
{2251799813685249.5, 2251799813685250}, // 1 bit fraction
{2251799813685250.5, 2251799813685251},
{4503599627370495.5, 4503599627370496}, // 1 bit fraction, rounding to 0 bit fraction
{4503599627370497, 4503599627370497}, // large integer
}
func TestRound(t *testing.T) {
for i := 0; i < len(vf); i++ {
if f := Round(vf[i]); !alike(round[i], f) {
t.Errorf("Round(%g) = %g, want %g", vf[i], f, round[i])
}
}
for i := 0; i < len(vfroundSC); i++ {
if f := Round(vfroundSC[i][0]); !alike(vfroundSC[i][1], f) {
t.Errorf("Round(%g) = %g, want %g", vfroundSC[i][0], f, vfroundSC[i][1])
}
}
}
func TestMinMax(t *testing.T) {
tests := []struct {
desc string
values []float64
wantMin float64
wantMax float64
}{
{
desc: "no values",
},
{
desc: "all values the same",
values: []float64{1.1, 1.1},
wantMin: 1.1,
wantMax: 1.1,
},
{
desc: "all values the same and negative",
values: []float64{-1.1, -1.1},
wantMin: -1.1,
wantMax: -1.1,
},
{
desc: "min and max among positive values",
values: []float64{1.1, 1.2, 1.3},
wantMin: 1.1,
wantMax: 1.3,
},
{
desc: "min and max among positive and zero values",
values: []float64{1.1, 0, 1.3},
wantMin: 0,
wantMax: 1.3,
},
{
desc: "min and max among negative, positive and zero values",
values: []float64{1.1, 0, 1.3, -11.3, 22.5},
wantMin: -11.3,
wantMax: 22.5,
},
}
for _, tc := range tests {
t.Run(tc.desc, func(t *testing.T) {
gotMin, gotMax := MinMax(tc.values)
if gotMin != tc.wantMin || gotMax != tc.wantMax {
t.Errorf("MinMax => (%v, %v), want (%v, %v)", gotMin, gotMax, tc.wantMin, tc.wantMax)
}
})
}
}
func TestMinMaxInts(t *testing.T) {
tests := []struct {
desc string
values []int
wantMin int
wantMax int
}{
{
desc: "no values",
},
{
desc: "all values the same",
values: []int{1, 1},
wantMin: 1,
wantMax: 1,
},
{
desc: "all values the same and negative",
values: []int{-1, -1},
wantMin: -1,
wantMax: -1,
},
{
desc: "min and max among positive values",
values: []int{1, 2, 3},
wantMin: 1,
wantMax: 3,
},
{
desc: "min and max among positive and zero values",
values: []int{1, 0, 3},
wantMin: 0,
wantMax: 3,
},
{
desc: "min and max among negative, positive and zero values",
values: []int{1, 0, 3, -11, 22},
wantMin: -11,
wantMax: 22,
},
}
for _, tc := range tests {
t.Run(tc.desc, func(t *testing.T) {
gotMin, gotMax := MinMaxInts(tc.values)
if gotMin != tc.wantMin || gotMax != tc.wantMax {
t.Errorf("MinMaxInts => (%v, %v), want (%v, %v)", gotMin, gotMax, tc.wantMin, tc.wantMax)
}
})
}
}
func TestDegreesToRadiansAndViceVersa(t *testing.T) {
tests := []struct {
degrees int
want float64
}{
{0, 0},
{1, 0.017453292519943295},
{-1, -0.017453292519943295},
{15, 0.2617993877991494},
{90, 1.5707963267948966},
{180, 3.141592653589793},
{270, 4.71238898038469},
{360, 6.283185307179586},
{361, 0.017453292519943295},
}
for _, tc := range tests {
t.Run(fmt.Sprintf("degrees %d", tc.degrees), func(t *testing.T) {
got := DegreesToRadians(tc.degrees)
if !veryclose(got, tc.want) {
t.Errorf("DegreesToRadians(%v) => %v, want %v", tc.degrees, got, tc.want)
}
})
}
}
func TestRadiansToDegrees(t *testing.T) {
tests := []struct {
radians float64
want int
}{
{0, 0},
{0.017453292519943295, 1},
{-0.017453292519943295, 359},
{-1.5707963267948966, 270},
{0.2617993877991494, 15},
{1.5707963267948966, 90},
{3.141592653589793, 180},
{4.71238898038469, 270},
{6.283185307179586, 360},
}
for _, tc := range tests {
t.Run(fmt.Sprintf("radians %v", tc.radians), func(t *testing.T) {
got := RadiansToDegrees(tc.radians)
if got != tc.want {
t.Errorf("RadiansToDegrees(%v) => %v, want %v", tc.radians, got, tc.want)
}
})
}
}
func TestAbs(t *testing.T) {
tests := []struct {
input int
want int
}{
{0, 0},
{1, 1},
{2, 2},
{-1, 1},
{-2, 2},
}
for _, tc := range tests {
t.Run(fmt.Sprintf("%d", tc.input), func(t *testing.T) {
got := Abs(tc.input)
if got != tc.want {
t.Errorf("Abs(%d) => %v, want %v", tc.input, got, tc.want)
}
})
}
}