blob: cff02d75a5092957606e1ccb1663bb92b8c81aed [file] [log] [blame]
 // Copyright ©2020 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 r2 import ( "math" "testing" "gonum.org/v1/gonum/floats/scalar" ) func TestAdd(t *testing.T) { for _, test := range []struct { v1, v2 Vec want Vec }{ {Vec{0, 0}, Vec{0, 0}, Vec{0, 0}}, {Vec{1, 0}, Vec{0, 0}, Vec{1, 0}}, {Vec{1, 2}, Vec{3, 4}, Vec{4, 6}}, {Vec{1, -3}, Vec{1, -6}, Vec{2, -9}}, {Vec{1, 2}, Vec{-1, -2}, Vec{}}, } { t.Run("", func(t *testing.T) { got := test.v1.Add(test.v2) if got != test.want { t.Fatalf( "error: %v + %v: got=%v, want=%v", test.v1, test.v2, got, test.want, ) } }) } } func TestSub(t *testing.T) { for _, test := range []struct { v1, v2 Vec want Vec }{ {Vec{0, 0}, Vec{0, 0}, Vec{0, 0}}, {Vec{1, 0}, Vec{0, 0}, Vec{1, 0}}, {Vec{1, 2}, Vec{3, 4}, Vec{-2, -2}}, {Vec{1, -3}, Vec{1, -6}, Vec{0, 3}}, {Vec{1, 2}, Vec{1, 2}, Vec{}}, } { t.Run("", func(t *testing.T) { got := test.v1.Sub(test.v2) if got != test.want { t.Fatalf( "error: %v - %v: got=%v, want=%v", test.v1, test.v2, got, test.want, ) } }) } } func TestScale(t *testing.T) { for _, test := range []struct { a float64 v Vec want Vec }{ {3, Vec{0, 0}, Vec{0, 0}}, {1, Vec{1, 0}, Vec{1, 0}}, {0, Vec{1, 0}, Vec{0, 0}}, {3, Vec{1, 0}, Vec{3, 0}}, {-1, Vec{1, -3}, Vec{-1, 3}}, {2, Vec{1, -3}, Vec{2, -6}}, {10, Vec{1, 2}, Vec{10, 20}}, } { t.Run("", func(t *testing.T) { got := test.v.Scale(test.a) if got != test.want { t.Fatalf( "error: %v * %v: got=%v, want=%v", test.a, test.v, got, test.want) } }) } } func TestDot(t *testing.T) { for _, test := range []struct { u, v Vec want float64 }{ {Vec{1, 2}, Vec{1, 2}, 5}, {Vec{1, 0}, Vec{1, 0}, 1}, {Vec{1, 0}, Vec{0, 1}, 0}, {Vec{1, 0}, Vec{0, 1}, 0}, {Vec{1, 1}, Vec{-1, -1}, -2}, {Vec{1, 2}, Vec{-0.3, 0.4}, 0.5}, } { t.Run("", func(t *testing.T) { { got := test.u.Dot(test.v) if got != test.want { t.Fatalf( "error: %v · %v: got=%v, want=%v", test.u, test.v, got, test.want, ) } } { got := test.v.Dot(test.u) if got != test.want { t.Fatalf( "error: %v · %v: got=%v, want=%v", test.v, test.u, got, test.want, ) } } }) } } func TestCross(t *testing.T) { for _, test := range []struct { v1, v2 Vec want float64 }{ {Vec{1, 0}, Vec{1, 0}, 0}, {Vec{1, 0}, Vec{0, 1}, 1}, {Vec{0, 1}, Vec{1, 0}, -1}, {Vec{1, 2}, Vec{-4, 5}, 13}, {Vec{1, 2}, Vec{2, 3}, -1}, } { t.Run("", func(t *testing.T) { got := test.v1.Cross(test.v2) if got != test.want { t.Fatalf( "error: %v × %v = %v, want %v", test.v1, test.v2, got, test.want, ) } }) } } func TestNorm(t *testing.T) { for _, test := range []struct { v Vec want float64 }{ {Vec{0, 0}, 0}, {Vec{0, 1}, 1}, {Vec{1, 1}, math.Sqrt2}, {Vec{1, 2}, math.Sqrt(5)}, {Vec{3, -4}, 5}, {Vec{1, 1e-16}, 1}, {Vec{4.3145006366056343748277397783556100978621924913975e-196, 4.3145006366056343748277397783556100978621924913975e-196}, 6.101625315155041e-196}, } { t.Run("", func(t *testing.T) { if got, want := Norm(test.v), test.want; got != want { t.Fatalf("|%v| = %v, want %v", test.v, got, want) } }) } } func TestNorm2(t *testing.T) { for _, test := range []struct { v Vec want float64 }{ {Vec{0, 0}, 0}, {Vec{0, 1}, 1}, {Vec{1, 1}, 2}, {Vec{1, 2}, 5}, {Vec{3, -4}, 25}, {Vec{1, 1e-16}, 1}, // This will underflow and return zero. {Vec{4.3145006366056343748277397783556100978621924913975e-196, 4.3145006366056343748277397783556100978621924913975e-196}, 0}, } { t.Run("", func(t *testing.T) { if got, want := Norm2(test.v), test.want; got != want { t.Fatalf("|%v|^2 = %v, want %v", test.v, got, want) } }) } } func TestUnit(t *testing.T) { for _, test := range []struct { v, want Vec }{ {Vec{}, Vec{math.NaN(), math.NaN()}}, {Vec{1, 0}, Vec{1, 0}}, {Vec{0, 1}, Vec{0, 1}}, {Vec{-1, 0}, Vec{-1, 0}}, {Vec{3, 4}, Vec{0.6, 0.8}}, {Vec{3, -4}, Vec{0.6, -0.8}}, {Vec{1, 1}, Vec{1. / math.Sqrt(2), 1. / math.Sqrt(2)}}, {Vec{1, 1e-16}, Vec{1, 1e-16}}, {Vec{1, 1e16}, Vec{1e-16, 1}}, {Vec{1e4, math.MaxFloat32 - 1}, Vec{0, 1}}, } { t.Run("", func(t *testing.T) { got := Unit(test.v) if !vecApproxEqual(got, test.want) { t.Fatalf( "Unit(%v) = %v, want %v", test.v, got, test.want, ) } if vecIsNaN(got) { return } if n, want := Norm(got), 1.0; n != want { t.Fatalf("|%v| = %v, want 1", got, n) } }) } } func TestCos(t *testing.T) { for _, test := range []struct { v1, v2 Vec want float64 }{ {Vec{1, 1}, Vec{1, 1}, 1}, {Vec{1, 1}, Vec{-1, -1}, -1}, {Vec{1, 0}, Vec{1, 0}, 1}, {Vec{1, 0}, Vec{0, 1}, 0}, {Vec{1, 0}, Vec{-1, 0}, -1}, } { t.Run("", func(t *testing.T) { tol := 1e-14 got := Cos(test.v1, test.v2) if !scalar.EqualWithinAbs(got, test.want, tol) { t.Fatalf("cos(%v, %v)= %v, want %v", test.v1, test.v2, got, test.want, ) } }) } } func TestRotate(t *testing.T) { for _, test := range []struct { v, q Vec alpha float64 want Vec }{ {Vec{1, 0}, Vec{0, 0}, math.Pi / 2, Vec{0, 1}}, {Vec{1, 0}, Vec{0, 0}, 3 * math.Pi / 2, Vec{0, -1}}, {Vec{1, 0}, Vec{0, 1}, 0, Vec{1, 0}}, {Vec{1, 0}, Vec{0, 1}, 2 * math.Pi, Vec{1, 0}}, {Vec{1, 1}, Vec{0, 0}, math.Pi, Vec{-1, -1}}, {Vec{2, 2}, Vec{1, 1}, math.Pi / 2, Vec{0, 2}}, {Vec{2, 2}, Vec{1, 1}, math.Pi, Vec{0, 0}}, {Vec{2, 2}, Vec{2, 0}, math.Pi, Vec{2, -2}}, } { got := test.v.Rotate(test.alpha, test.q) if !vecApproxEqual(got, test.want) { t.Errorf( "rotate(%v, %v, %v)= %v, want=%v", test.v, test.alpha, test.q, got, test.want, ) } } } func vecIsNaN(v Vec) bool { return math.IsNaN(v.X) && math.IsNaN(v.Y) } func vecIsNaNAny(v Vec) bool { return math.IsNaN(v.X) || math.IsNaN(v.Y) } func vecApproxEqual(a, b Vec) bool { const tol = 1e-14 if vecIsNaNAny(a) || vecIsNaNAny(b) { return vecIsNaN(a) && vecIsNaN(b) } return scalar.EqualWithinAbs(a.X, b.X, tol) && scalar.EqualWithinAbs(a.Y, b.Y, tol) }