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class Matrix {
constructor(rows, cols) {
this.rows = rows;
this.cols = cols;
this.data = Array(this.rows).fill().map(() => Array(this.cols).fill(0));
}
copy() {
let m = new Matrix(this.rows, this.cols);
for (let i = 0; i < this.rows; i++) {
for (let j = 0; j < this.cols; j++) {
m.data[i][j] = this.data[i][j];
}
}
return m;
}
static fromArray(arr) {
return new Matrix(arr.length, 1).map((e, i) => arr[i]);
}
static subtract(a, b) {
if (a.rows !== b.rows || a.cols !== b.cols) {
console.log('Columns and Rows of A must match Columns and Rows of B.');
return;
}
// Return a new Matrix a-b
return new Matrix(a.rows, a.cols)
.map((_, i, j) => a.data[i][j] - b.data[i][j]);
}
toArray() {
let arr = [];
for (let i = 0; i < this.rows; i++) {
for (let j = 0; j < this.cols; j++) {
arr.push(this.data[i][j]);
}
}
return arr;
}
randomize() {
return this.map(e => Math.random() * 2 - 1);
}
add(n) {
if (n instanceof Matrix) {
if (this.rows !== n.rows || this.cols !== n.cols) {
console.log('Columns and Rows of A must match Columns and Rows of B.');
return;
}
return this.map((e, i, j) => e + n.data[i][j]);
} else {
return this.map(e => e + n);
}
}
static transpose(matrix) {
return new Matrix(matrix.cols, matrix.rows)
.map((_, i, j) => matrix.data[j][i]);
}
static multiply(a, b) {
// Matrix product
if (a.cols !== b.rows) {
console.log('Columns of A must match rows of B.');
return;
}
return new Matrix(a.rows, b.cols)
.map((e, i, j) => {
// Dot product of values in col
let sum = 0;
for (let k = 0; k < a.cols; k++) {
sum += a.data[i][k] * b.data[k][j];
}
return sum;
});
}
multiply(n) {
if (n instanceof Matrix) {
if (this.rows !== n.rows || this.cols !== n.cols) {
console.log('Columns and Rows of A must match Columns and Rows of B.');
return;
}
// hadamard product
return this.map((e, i, j) => e * n.data[i][j]);
} else {
// Scalar product
return this.map(e => e * n);
}
}
map(func) {
// Apply a function to every element of matrix
for (let i = 0; i < this.rows; i++) {
for (let j = 0; j < this.cols; j++) {
let val = this.data[i][j];
this.data[i][j] = func(val, i, j);
}
}
return this;
}
static map(matrix, func) {
// Apply a function to every element of matrix
return new Matrix(matrix.rows, matrix.cols)
.map((e, i, j) => func(matrix.data[i][j], i, j));
}
print() {
console.table(this.data);
return this;
}
serialize() {
return JSON.stringify(this);
}
static deserialize(data) {
if (typeof data == 'string') {
data = JSON.parse(data);
}
let matrix = new Matrix(data.rows, data.cols);
matrix.data = data.data;
return matrix;
}
}
if (typeof module !== 'undefined') {
module.exports = Matrix;
}