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mat2x2.go
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mat2x2.go
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// Generated code. DO NOT EDIT
package mat
import (
"github.com/chewxy/math32"
"github.com/itohio/EasyRobot/pkg/core/math/vec"
)
type Matrix2x2 [2][2]float32
func New2x2(arr ...float32) Matrix2x2 {
m := Matrix2x2{}
if arr != nil {
for i := range m {
copy(m[i][:], arr[i*2 : i*2+2][:])
}
}
return m
}
// Returns a flat representation of this matrix.
func (m *Matrix2x2) Flat(v vec.Vector) vec.Vector {
N := len(m[0])
for i, row := range m {
copy(v[i*N:i*N+N], row[:])
}
return v
}
// Returns a Matrix view of this matrix.
// The view actually contains slices of original matrix rows.
// This way original matrix can be modified.
func (m *Matrix2x2) Matrix() Matrix {
m1 := make(Matrix, len(m))
for i := range m {
m1[i] = m[i][:]
}
return m1
}
// Fills destination matrix with a 2D rotation
// Matrix size must be at least 2x2
func (m *Matrix2x2) Rotation2D(a float32) *Matrix2x2 {
c := math32.Cos(a)
s := math32.Sin(a)
return m.SetSubmatrixRaw(0, 0, 2, 2,
c, -s,
s, c,
)
}
// Fills destination matrix with identity matrix.
func (m *Matrix2x2) Eye() *Matrix2x2 {
for i := range m {
row := m[i][:]
for j := range row {
row[j] = 0
}
}
for i := range m {
m[i][i] = 1
}
return m
}
// Returns a slice to the row.
func (m *Matrix2x2) Row(row int) vec.Vector {
return m[row][:]
}
// Returns a copy of the matrix column.
func (m *Matrix2x2) Col(col int, v vec.Vector) vec.Vector {
for i, row := range m {
v[i] = row[col]
}
return v
}
func (m *Matrix2x2) SetRow(row int, v vec.Vector) *Matrix2x2 {
copy(m[row][:], v[:])
return m
}
func (m *Matrix2x2) SetCol(col int, v vec.Vector) *Matrix2x2 {
for i, v := range v {
m[i][col] = v
}
return m
}
// Size of the destination vector must equal to number of rows
func (m *Matrix2x2) Diagonal(dst vec.Vector) vec.Vector {
for i, row := range m {
dst[i] = row[i]
}
return dst
}
// Size of the vector must equal to number of rows
func (m *Matrix2x2) SetDiagonal(v vec.Vector2D) *Matrix2x2 {
for i, v := range v {
m[i][i] = v
}
return m
}
func (m *Matrix2x2) Submatrix(row, col int, m1 Matrix) Matrix {
cols := len(m1[0])
for i, m1row := range m1 {
copy(m1row, m[row+i][col : cols+col][:])
}
return m1
}
func (m *Matrix2x2) SetSubmatrix(row, col int, m1 Matrix) *Matrix2x2 {
for i := range m[row : row+len(m1)] {
copy(m[row+i][col : col+len(m1[i])][:], m1[i][:])
}
return m
}
func (m *Matrix2x2) SetSubmatrixRaw(row, col, rows1, cols1 int, m1 ...float32) *Matrix2x2 {
for i := 0; i < rows1; i++ {
copy(m[row+i][col : col+cols1][:], m1[i*cols1:i*cols1+cols1])
}
return m
}
func (m *Matrix2x2) Clone() *Matrix2x2 {
m1 := &Matrix2x2{}
for i, row := range m {
copy(m1[i][:], row[:])
}
return m1
}
// Transposes matrix m1 and stores the result in the destination matrix
// destination matrix must be of appropriate size.
// NOTE: Does not support in place transpose
func (m *Matrix2x2) Transpose(m1 Matrix2x2) *Matrix2x2 {
for i, row := range m1 {
for j, val := range row {
m[j][i] = val
}
}
return m
}
func (m *Matrix2x2) Add(m1 Matrix2x2) *Matrix2x2 {
for i := range m {
vec.Vector(m[i][:]).Add(m1[i][:])
}
return m
}
func (m *Matrix2x2) Sub(m1 Matrix2x2) *Matrix2x2 {
for i := range m {
vec.Vector(m[i][:]).Sub(m1[i][:])
}
return m
}
func (m *Matrix2x2) MulC(c float32) *Matrix2x2 {
for i := range m {
vec.Vector(m[i][:]).MulC(c)
}
return m
}
func (m *Matrix2x2) DivC(c float32) *Matrix2x2 {
for i := range m {
vec.Vector(m[i][:]).DivC(c)
}
return m
}
// Destination matrix must be properly sized.
// given that a is MxN and b is NxK
// then destinatiom matrix must be MxK
func (m *Matrix2x2) Mul(a Matrix2x2, b Matrix2x2) *Matrix2x2 {
for i, row := range a {
mrow := m[i][:]
for j := range mrow {
var sum float32
for k, brow := range b {
sum += row[k] * brow[j]
}
mrow[j] = sum
}
}
return m
}
// Only makes sense for square matrices.
// Vector size must be equal to number of rows/cols
func (m *Matrix2x2) MulDiag(a Matrix2x2, b vec.Vector2D) *Matrix2x2 {
for i, row := range a {
mrow := m[i][:]
for j := range row {
mrow[j] = row[j] * b[j]
}
}
return m
}
// Vector must have a size equal to number of cols.
// Destination vector must have a size equal to number of rows.
func (m *Matrix2x2) MulVec(v vec.Vector2D, dst vec.Vector) vec.Vector {
for i, row := range m {
var sum float32
for j, val := range row {
sum += v[j] * val
}
dst[i] = sum
}
return dst
}
// Vector must have a size equal to number of rows.
// Destination vector must have a size equal to number of cols.
func (m *Matrix2x2) MulVecT(v vec.Vector2D, dst vec.Vector) vec.Vector {
for i := range m[0] {
var sum float32
for j, val := range m {
sum += v[j] * val[i]
}
dst[i] = sum
}
return dst
}
// Determinant only valid for square matrix
// Undefined behavior for non square matrices
func (m *Matrix2x2) Det() float32 {
tmp := m.Clone()
var ratio float32
var det float32 = 1
// upper triangular
for i, row := range tmp {
for j := range row {
if j > i {
tmpj := tmp[j][:]
ratio = tmpj[i] / row[i]
for k := range tmp {
tmpj[k] -= ratio * row[k]
}
}
}
}
for i, row := range tmp {
det *= row[i]
}
return det
}
//
// LU decomposition into two triangular matrices
// NOTE: Assume, that l&u matrices are set to zero
// Matrix must be square and M, L and U matrix sizes must be equal
func (m *Matrix2x2) LU(L, U *Matrix2x2) {
for i := range m {
// Upper Triangular
for k := i; k < len(m); k++ {
// Summation of L(i, j) * U(j, k)
var sum float32
for j := 0; j < i; j++ {
sum += L[i][j] * U[j][k]
}
// Evaluating U(i, k)
U[i][k] = m[i][k] - sum
}
// Lower Triangular
for k := i; k < len(m); k++ {
if i == k {
L[i][i] = 1 // Diagonal as 1
} else {
// Summation of L(k, j) * U(j, i)
var sum float32
for j := 0; j < i; j++ {
sum += L[k][j] * U[j][i]
}
// Evaluating L(k, i)
L[k][i] = (m[k][i] - sum) / U[i][i]
}
}
}
}