Better Gaussian elimination & vector class

__tests__/matrix.ts

@@ -32,13 +32,11 @@ test('Multiply (B, A, C)', () => {
 	expect(B.mul(A).eq(C)).toBe(false);
 });
 
-let D = new GaussianElimination(
-	new Matrix(
-		[1, 2, -1, 1, 2],
-		[2, 5, 0, 1, 5],
-		[3, 7, -1, 3, 9],
-		[1, 3, 1, 1, 5]
-	)
+let D = new Matrix(
+	[1, 2, -1, 1, 2],
+	[2, 5, 0, 1, 5],
+	[3, 7, -1, 3, 9],
+	[1, 3, 1, 1, 5]
 );
 
 let D_solved = new Matrix(
@@ -49,14 +47,12 @@ let D_solved = new Matrix(
 );
 
 test('Gaussian elimination (D)', () => {
-	expect(D.solve().eq(D_solved)).toBe(true);
+	expect(GaussianElimination.ge(D).eq(D_solved)).toBe(true);
 });
 
-let E = new GaussianElimination(
-	new Matrix(
-		[1, 1, 3],
-		[2, -1, 4]
-	)
+let E = new Matrix(
+	[1, 1, 3],
+	[2, -1, 4]
 );
 
 let E_solved = new Matrix(
@@ -65,23 +61,52 @@ let E_solved = new Matrix(
 );
 
 test('Gaussian elimination (E)', () => {
-	expect(E.solve().eq(E_solved)).toBe(true);
+	expect(GaussianElimination.ge(E).eq(E_solved)).toBe(true);
 });
 
 let F = new Matrix(
+	[2, 1, -1, 8],
+	[-3, -1, 2, -11],
+	[-2, 1, 2, -3]
+);
+
+let F_solved = new Matrix(
+	[2, 0, 0, 4],
+	[0, 0.5, 0, 1.5],
+	[0, 0, -1, 1]
+);
+
+let F_results = GaussianElimination.solve(F);
+
+test('Gauss-Jordan elimination (F)', () => {
+	expect(GaussianElimination.gje(F).eq(F_solved)).toBe(true);
+});
+
+test('Only one result of Gauss-Jordan elimination (F)', () => {
+	expect(F_results instanceof Matrix).toBe(false);
+});
+
+test('Results of Gauss-Jordan elimination (F)', () => {
+	[2, 3, -1].forEach((result, i) => { 
+		if(F_results instanceof Matrix) throw("Result is matrix!");
+		expect(result == F_results[i]).toBe(true);
+	});
+});
+
+let G = new Matrix(
 	[1, 1, 1],
 	[0, 2, 4],
 	[0, 0, 5],
 );
 
-let G = new Matrix(
+let I = new Matrix(
 	[1, 0, 0],
 	[5, 2, 0],
 	[4, 8, 5],
 );
 
 test('Upper triangular matrix (F)', () => {
-	expect(F.is_triangular()).toBe(true);
+	expect(G.is_triangular()).toBe(true);
 });
 
 test('Upper triangular matrix (A)', () => {
@@ -89,5 +114,5 @@ test('Upper triangular matrix (A)', () => {
 });
 
 test('Lower triangular matrix (G)', () => {
-	expect(G.is_triangular(TriangularForm.LOWER)).toBe(true);
+	expect(I.is_triangular(TriangularForm.LOWER)).toBe(true);
 });

matrix.ts

@@ -122,7 +122,6 @@ export class Matrix {
 		let pivot_index = -1;
 		for(let i=0; i<this.rows; i++) {
 			for(let j=0; j<this.cols; j++) {
-				console.log(this.matrix[i][j], pivot_index);
 				if(this.matrix[i][j] == 0) {
 					if(j > pivot_index) pivot_index = j;
 				} else if(pivot_index >= j) return false;
@@ -155,46 +154,77 @@ export class Matrix {
 		return pivots;
 	}
 
+	remove_row(row: number) {
+		let m = [...this.matrix];
+		m.splice(row, 1); this.set(...m);
+	}
+
 }
 
 
-export class GaussianElimination {
+export abstract class GaussianElimination {
 
-	matrix: Matrix;
-
-	constructor(matrix: Matrix) {
-		this.matrix = matrix;
+	static make_pivot_1(row: number[]) {
+		let d = 0;
+		return row.map((n, i) => {
+			if(n != 0 && !d) d = n;
+			return d && n ? n / d : 0;
+		});
 	}
 
-	sort() {
-		let matrix = this.matrix.matrix;
-		let new_matrix = [matrix[0]];
-		let pivots = this.matrix.pivots();
+	static sort(matrix: Matrix) {
+		let m = matrix.matrix;
+		let new_matrix = [m[0]];
+		let pivots = matrix.pivots();
 		for(let i=1; i<pivots.length; i++) {
-			if(pivots[i] < pivots[i-1]) new_matrix.unshift(matrix[i]);
-			else new_matrix.push(matrix[i]);
+			if(pivots[i] < pivots[i-1]) new_matrix.unshift(m[i]);
+			else new_matrix.push(m[i]);
 		}
-		this.matrix.set(...new_matrix);
+		return new Matrix(...new_matrix);
 	}
 
-	solve() {
-		for(let v_offset=0; v_offset<this.matrix.rows; v_offset++) {
-			this.sort();
-			let matrix = this.matrix.matrix;
-			let h_offset = this.matrix.pivots()[v_offset];
-			let first_number = matrix[v_offset][h_offset];
-			for(let i=1+v_offset; i<matrix.length; i++) {
-				let n = -matrix[i][h_offset]/first_number;
-				this.matrix.matrix[i] = matrix[i].map((c, j) => c + n*matrix[v_offset][j]);
+	static ge(matrix: Matrix): Matrix {
+		for(let v_offset=0; v_offset<matrix.rows; v_offset++) {
+			matrix = this.sort(matrix);
+			let m = matrix.matrix;
+			let h_offset = matrix.pivots()[v_offset];
+			let first_number = m[v_offset][h_offset];
+			for(let i=1+v_offset; i<matrix.rows; i++) {
+				let n = -m[i][h_offset]/first_number;
+				m[i] = m[i].map((c, j) => c + n*m[v_offset][j]);
 			}
 		}
-		return this.matrix;
+		return matrix;
 	}
 
-	mul_row(index: number, number: number, replace: boolean = false) {
-		let row = this.matrix.matrix[index].map(original => number * original);
-		if(replace) this.matrix.matrix[index] = row;
-		return row;
+	static gje(matrix: Matrix): Matrix {
+		matrix = this.ge(matrix);
+		let pivots = matrix.pivots();
+		for(let v_offset=matrix.rows-1; v_offset>0; v_offset--) {
+			let m = matrix.matrix;
+			let h_offset = pivots[v_offset];
+			if(h_offset >= matrix.cols) continue;
+			let first_number = m[v_offset][h_offset];
+			for(let i=v_offset-1; i>=0; i--) {
+				let n = -m[i][h_offset]/first_number;
+				m[i] = m[i].map((c, j) => c + n*m[v_offset][j]);
+			}
+		}
+		return matrix;
+	}
+
+	static solve(matrix: Matrix): number[] | Matrix {
+		let solved_matrix = this.gje(matrix);
+		let pivots = solved_matrix.pivots();
+		let results: number[] = [];
+		solved_matrix.matrix = solved_matrix.matrix.map(GaussianElimination.make_pivot_1);
+		for(let row=0; row<solved_matrix.rows; row++) {
+			let col = pivots[row];
+			let pivot = solved_matrix.matrix[row][col];
+			results.push(solved_matrix.matrix[row][solved_matrix.cols-1]/pivot);
+		}
+		if(results.filter(n => isNaN(n)).length == 0) return results;
+		else return solved_matrix;
 	}
 
 }

vector.ts

@@ -0,0 +1,30 @@
+import { GaussianElimination, Matrix, RawMatrix } from "./matrix";
+
+export class Vector extends Matrix {
+
+	constructor(...coords: number[]) {
+		let rm: RawMatrix = coords.map(c => [c]);
+		super(...rm);
+	}
+
+	coords() {
+		return this.matrix.map(row => row[0]);
+	}
+
+}
+
+export class LinearIndependence {
+
+	vectors: Vector[];
+
+	constructor(...v: Vector[]) {
+		this.vectors = v;
+	}
+
+	check(): [boolean, (number[] | Matrix)] {
+		let rows = this.vectors.map(v => [...v.coords(), 0]);
+		let result = GaussianElimination.solve(new Matrix(...rows));
+		return [!(result instanceof Matrix), result];
+	}
+
+}