commit 1e5f2aaf6b76dc5e912bd830f92b490f0a8962f8
Author: Filip Znachor <filip@znachor.cz>
Date:   Thu Sep 29 19:14:19 2022 +0200

    Matrix class

diff --git a/matrix.ts b/matrix.ts
new file mode 100644
index 0000000..95f49bc
--- /dev/null
+++ b/matrix.ts
@@ -0,0 +1,97 @@
+
+type RawMatrix = number[][];
+
+class Matrix {
+
+	rows: number;
+	cols: number;
+	matrix: RawMatrix;
+
+	static zero(rows: number, cols: number) {
+		let matrix: RawMatrix = [];
+		for(let i=0; i<rows; i++) {
+			matrix.push([]);
+			for(let j=0; j<cols; j++) {
+				matrix[i].push(0);
+			}
+		}
+		return new Matrix(...matrix);
+	}
+
+	constructor(...matrix: RawMatrix) {
+		this.matrix = matrix;
+		this.rows = matrix.length;
+		if(matrix.length == 0) throw Error("Empty matrix");
+		this.cols = matrix[0].length;
+		for(let i=0; i<matrix.length; i++) {
+			if(matrix[i].length !== this.cols) throw Error("Invalid matrix row " + (i+1));
+		}
+	}
+
+	add(other_matrix: Matrix) {
+		if(!(other_matrix.cols == this.cols && other_matrix.rows == this.cols)) throw Error("Other matrix has more or few rows or columns");
+		for(let i=0; i<this.matrix.length; i++) {
+			for(let j=0; j<this.matrix[i].length; j++) {
+				this.matrix[i][j] += other_matrix.matrix[i][j];
+			}
+		}
+		return this;
+	}
+
+	sub(other_matrix: Matrix) {
+		if(!(other_matrix.cols == this.cols && other_matrix.rows == this.cols)) throw Error("Other matrix has more or few rows or columns");
+		for(let i=0; i<this.matrix.length; i++) {
+			for(let j=0; j<this.matrix[i].length; j++) {
+				this.matrix[i][j] -= other_matrix.matrix[i][j];
+			}
+		}
+		return this;
+	}
+
+	mul(other: Matrix | number) {
+		if(other instanceof Matrix) {
+			if(!(this.cols == other.rows)) throw Error("These matrices cannot be multiplied");
+			let final_matrix: RawMatrix = [];
+			for(let a_row_i=0; a_row_i<this.matrix.length; a_row_i++) {
+				final_matrix.push([]);
+				for(let b_col_i=0; b_col_i<other.matrix[0].length; b_col_i++) {
+					let sum = 0;
+					for(let a_col_b_row_i=0; a_col_b_row_i<this.matrix[0].length; a_col_b_row_i++) {
+						sum += this.matrix[a_row_i][a_col_b_row_i] * other.matrix[a_col_b_row_i][b_col_i];
+					}
+					final_matrix[a_row_i].push(sum);
+				}
+			}
+			return new Matrix(...final_matrix);
+		} else {
+			for(let i=0; i<this.matrix.length; i++) {
+				for(let j=0; j<this.matrix[i].length; j++) {
+					this.matrix[i][j] = this.matrix[i][j] * other;
+				}
+			}
+			return this;
+		}
+	}
+
+	pow(power: number) {
+		for(let i=0; i<(power-1); i++)
+			this.matrix = this.mul(this).matrix;
+		return this;
+	}
+
+	invert() {
+		this.matrix = this.mul(-1).matrix;
+		return this;
+	}
+
+	transpose() {
+		let new_matrix = Matrix.zero(this.cols, this.rows);
+		for(let i=0; i<this.rows; i++) {
+			for(let j=0; j<this.cols; j++) {
+				new_matrix.matrix[j][i] = this.matrix[i][j];
+			}
+		}
+		return new_matrix;
+	}
+
+}
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