spatial/r3: add Mat type

spatial/r3/mat_test.go

@@ -0,0 +1,103 @@
+// Copyright ©2021 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 r3
+
+import (
+	"math"
+	"testing"
+
+	"golang.org/x/exp/rand"
+
+	"gonum.org/v1/gonum/mat"
+)
+
+func TestMatScale(t *testing.T) {
+	const tol = 1e-12
+	rnd := rand.New(rand.NewSource(1))
+	for tc := 0; tc < 20; tc++ {
+		v := rnd.Float64()
+		a := randomMat(rnd)
+		gotmat := NewMat(nil)
+		gotmat.Scale(v, a)
+		for iv := range a.data {
+			i := iv / 3
+			j := iv % 3
+			expect := v * a.At(i, j)
+			got := gotmat.At(i, j)
+			if math.Abs(got-expect) > tol {
+				t.Errorf(
+					"case %d: got=%v, want=%v",
+					tc, got, expect)
+			}
+		}
+	}
+}
+
+func TestMatCloneFrom(t *testing.T) {
+	rnd := rand.New(rand.NewSource(1))
+	for tc := 0; tc < 20; tc++ {
+		a := randomMat(rnd)
+		gotmat := NewMat(nil)
+		gotmat.CloneFrom(a)
+		if !mat.Equal(a, gotmat) {
+			t.Error("Clonefrom fail")
+		}
+	}
+}
+
+func TestSkew(t *testing.T) {
+	rnd := rand.New(rand.NewSource(1))
+	for tc := 0; tc < 20; tc++ {
+		v1 := randomVec(rnd)
+		v2 := randomVec(rnd)
+		sk := Skew(v1)
+		got := sk.MulVec(v2)
+		expect := Cross(v1, v2)
+		if got != expect {
+			t.Error("r3.Cross(v1,v2) not match with r3.Skew(v1)*v2")
+		}
+	}
+}
+
+func TestTranspose(t *testing.T) {
+	rnd := rand.New(rand.NewSource(1))
+	for tc := 0; tc < 20; tc++ {
+		d := mat.NewDense(3, 3, nil)
+		m := randomMat(rnd)
+		d.CloneFrom(m)
+		mt := m.T()
+		dt := d.T()
+		if !mat.Equal(mt, dt) {
+			t.Error("Dense.T() not equal to r3.Mat.T()")
+		}
+		vd := mat.NewVecDense(3, nil)
+		v := randomVec(rnd)
+		vd.SetVec(0, v.X)
+		vd.SetVec(1, v.Y)
+		vd.SetVec(2, v.Z)
+		got := m.MulVecTrans(v)
+		vd.MulVec(dt, vd)
+		if vd.AtVec(0) != got.X || vd.AtVec(1) != got.Y || vd.AtVec(2) != got.Z {
+			t.Error("VecDense.MulVec(dense.T()) not equal to r3.Mat.MulVec(r3.Vec)")
+		}
+	}
+}
+
+func randomMat(rnd *rand.Rand) *Mat {
+	m := Mat{data: new([3][3]float64)}
+	for iv := 0; iv < 9; iv++ {
+		i := iv / 3
+		j := iv % 3
+		m.Set(i, j, (rnd.Float64()-0.5)*20)
+	}
+	return &m
+}
+
+func randomVec(rnd *rand.Rand) (v Vec) {
+	v.X = (rnd.Float64() - 0.5) * 20
+	v.Y = (rnd.Float64() - 0.5) * 20
+	v.Z = (rnd.Float64() - 0.5) * 20
+	return v
+}