mirror of
https://github.com/gonum/gonum.git
synced 2025-10-05 23:26:52 +08:00
283 lines
6.1 KiB
Go
283 lines
6.1 KiB
Go
// Copyright ©2020 The Gonum Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package r2
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import (
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"math"
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"testing"
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"golang.org/x/exp/rand"
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"gonum.org/v1/gonum/floats/scalar"
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)
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func TestAdd(t *testing.T) {
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for _, test := range []struct {
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v1, v2 Vec
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want Vec
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}{
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{Vec{0, 0}, Vec{0, 0}, Vec{0, 0}},
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{Vec{1, 0}, Vec{0, 0}, Vec{1, 0}},
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{Vec{1, 2}, Vec{3, 4}, Vec{4, 6}},
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{Vec{1, -3}, Vec{1, -6}, Vec{2, -9}},
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{Vec{1, 2}, Vec{-1, -2}, Vec{}},
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} {
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got := Add(test.v1, test.v2)
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if got != test.want {
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t.Errorf(
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"error: %v + %v: got=%v, want=%v",
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test.v1, test.v2, got, test.want,
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)
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}
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}
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}
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func TestSub(t *testing.T) {
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for _, test := range []struct {
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v1, v2 Vec
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want Vec
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}{
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{Vec{0, 0}, Vec{0, 0}, Vec{0, 0}},
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{Vec{1, 0}, Vec{0, 0}, Vec{1, 0}},
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{Vec{1, 2}, Vec{3, 4}, Vec{-2, -2}},
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{Vec{1, -3}, Vec{1, -6}, Vec{0, 3}},
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{Vec{1, 2}, Vec{1, 2}, Vec{}},
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} {
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got := Sub(test.v1, test.v2)
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if got != test.want {
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t.Errorf(
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"error: %v - %v: got=%v, want=%v",
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test.v1, test.v2, got, test.want,
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)
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}
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}
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}
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func TestScale(t *testing.T) {
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for _, test := range []struct {
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a float64
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v Vec
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want Vec
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}{
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{3, Vec{0, 0}, Vec{0, 0}},
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{1, Vec{1, 0}, Vec{1, 0}},
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{0, Vec{1, 0}, Vec{0, 0}},
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{3, Vec{1, 0}, Vec{3, 0}},
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{-1, Vec{1, -3}, Vec{-1, 3}},
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{2, Vec{1, -3}, Vec{2, -6}},
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{10, Vec{1, 2}, Vec{10, 20}},
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} {
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got := Scale(test.a, test.v)
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if got != test.want {
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t.Errorf(
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"error: %v * %v: got=%v, want=%v",
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test.a, test.v, got, test.want)
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}
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}
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}
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func TestDot(t *testing.T) {
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for _, test := range []struct {
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u, v Vec
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want float64
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}{
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{Vec{1, 2}, Vec{1, 2}, 5},
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{Vec{1, 0}, Vec{1, 0}, 1},
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{Vec{1, 0}, Vec{0, 1}, 0},
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{Vec{1, 0}, Vec{0, 1}, 0},
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{Vec{1, 1}, Vec{-1, -1}, -2},
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{Vec{1, 2}, Vec{-0.3, 0.4}, 0.5},
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} {
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{
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got := Dot(test.u, test.v)
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if got != test.want {
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t.Errorf(
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"error: %v · %v: got=%v, want=%v",
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test.u, test.v, got, test.want,
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)
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}
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}
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{
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got := Dot(test.v, test.u)
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if got != test.want {
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t.Errorf(
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"error: %v · %v: got=%v, want=%v",
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test.v, test.u, got, test.want,
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)
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}
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}
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}
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}
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func TestCross(t *testing.T) {
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for _, test := range []struct {
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v1, v2 Vec
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want float64
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}{
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{Vec{1, 0}, Vec{1, 0}, 0},
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{Vec{1, 0}, Vec{0, 1}, 1},
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{Vec{0, 1}, Vec{1, 0}, -1},
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{Vec{1, 2}, Vec{-4, 5}, 13},
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{Vec{1, 2}, Vec{2, 3}, -1},
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} {
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got := Cross(test.v1, test.v2)
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if got != test.want {
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t.Errorf(
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"error: %v × %v = %v, want %v",
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test.v1, test.v2, got, test.want,
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)
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}
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}
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}
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func TestNorm(t *testing.T) {
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for _, test := range []struct {
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v Vec
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want float64
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}{
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{Vec{0, 0}, 0},
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{Vec{0, 1}, 1},
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{Vec{1, 1}, math.Sqrt2},
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{Vec{1, 2}, math.Sqrt(5)},
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{Vec{3, -4}, 5},
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{Vec{1, 1e-16}, 1},
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{Vec{4.3145006366056343748277397783556100978621924913975e-196, 4.3145006366056343748277397783556100978621924913975e-196}, 6.101625315155041e-196},
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} {
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if got, want := Norm(test.v), test.want; got != want {
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t.Errorf("|%v| = %v, want %v", test.v, got, want)
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}
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}
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}
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func TestNorm2(t *testing.T) {
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for _, test := range []struct {
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v Vec
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want float64
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}{
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{Vec{0, 0}, 0},
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{Vec{0, 1}, 1},
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{Vec{1, 1}, 2},
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{Vec{1, 2}, 5},
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{Vec{3, -4}, 25},
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{Vec{1, 1e-16}, 1},
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// This will underflow and return zero.
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{Vec{4.3145006366056343748277397783556100978621924913975e-196, 4.3145006366056343748277397783556100978621924913975e-196}, 0},
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} {
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if got, want := Norm2(test.v), test.want; got != want {
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t.Errorf("|%v|^2 = %v, want %v", test.v, got, want)
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}
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}
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}
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func TestUnit(t *testing.T) {
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const tol = 1e-14
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for _, test := range []struct {
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v, want Vec
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}{
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{Vec{}, Vec{math.NaN(), math.NaN()}},
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{Vec{1, 0}, Vec{1, 0}},
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{Vec{0, 1}, Vec{0, 1}},
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{Vec{-1, 0}, Vec{-1, 0}},
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{Vec{3, 4}, Vec{0.6, 0.8}},
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{Vec{3, -4}, Vec{0.6, -0.8}},
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{Vec{1, 1}, Vec{1. / math.Sqrt(2), 1. / math.Sqrt(2)}},
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{Vec{1, 1e-16}, Vec{1, 1e-16}},
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{Vec{1, 1e16}, Vec{1e-16, 1}},
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{Vec{1e4, math.MaxFloat32 - 1}, Vec{0, 1}},
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} {
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got := Unit(test.v)
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if !vecApproxEqual(got, test.want, tol) {
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t.Errorf(
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"Unit(%v) = %v, want %v",
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test.v, got, test.want,
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)
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}
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if vecIsNaN(got) {
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return
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}
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if n, want := Norm(got), 1.0; n != want {
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t.Errorf("|%v| = %v, want 1", got, n)
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}
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}
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}
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func TestCos(t *testing.T) {
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const tol = 1e-14
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for _, test := range []struct {
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v1, v2 Vec
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want float64
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}{
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{Vec{1, 1}, Vec{1, 1}, 1},
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{Vec{1, 1}, Vec{-1, -1}, -1},
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{Vec{1, 0}, Vec{1, 0}, 1},
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{Vec{1, 0}, Vec{0, 1}, 0},
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{Vec{1, 0}, Vec{-1, 0}, -1},
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} {
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got := Cos(test.v1, test.v2)
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if !scalar.EqualWithinAbs(got, test.want, tol) {
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t.Errorf("cos(%v, %v)= %v, want %v",
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test.v1, test.v2, got, test.want,
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)
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}
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}
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}
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func TestRotate(t *testing.T) {
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const tol = 1e-14
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for _, test := range []struct {
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v, q Vec
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alpha float64
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want Vec
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}{
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{Vec{1, 0}, Vec{0, 0}, math.Pi / 2, Vec{0, 1}},
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{Vec{1, 0}, Vec{0, 0}, 3 * math.Pi / 2, Vec{0, -1}},
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{Vec{1, 0}, Vec{0, 1}, 0, Vec{1, 0}},
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{Vec{1, 0}, Vec{0, 1}, 2 * math.Pi, Vec{1, 0}},
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{Vec{1, 1}, Vec{0, 0}, math.Pi, Vec{-1, -1}},
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{Vec{2, 2}, Vec{1, 1}, math.Pi / 2, Vec{0, 2}},
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{Vec{2, 2}, Vec{1, 1}, math.Pi, Vec{0, 0}},
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{Vec{2, 2}, Vec{2, 0}, math.Pi, Vec{2, -2}},
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} {
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got := Rotate(test.v, test.alpha, test.q)
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if !vecApproxEqual(got, test.want, tol) {
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t.Errorf(
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"rotate(%v, %v, %v)= %v, want=%v",
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test.v, test.alpha, test.q, got, test.want,
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)
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}
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}
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}
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func vecIsNaN(v Vec) bool {
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return math.IsNaN(v.X) && math.IsNaN(v.Y)
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}
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func vecIsNaNAny(v Vec) bool {
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return math.IsNaN(v.X) || math.IsNaN(v.Y)
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}
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func vecApproxEqual(a, b Vec, tol float64) bool {
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if tol == 0 {
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return vecEqual(a, b)
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}
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if vecIsNaNAny(a) || vecIsNaNAny(b) {
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return vecIsNaN(a) && vecIsNaN(b)
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}
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return scalar.EqualWithinAbs(a.X, b.X, tol) &&
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scalar.EqualWithinAbs(a.Y, b.Y, tol)
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}
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func randomVec(rnd *rand.Rand) (v Vec) {
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v.X = (rnd.Float64() - 0.5) * 20
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v.Y = (rnd.Float64() - 0.5) * 20
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return v
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}
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func vecEqual(a, b Vec) bool {
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if vecIsNaNAny(a) || vecIsNaNAny(b) {
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return vecIsNaN(a) && vecIsNaN(b)
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}
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return a == b
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}
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