From 7f81de90205cdd881c240e27d4da3d1cb4ca4529 Mon Sep 17 00:00:00 2001
From: Adam Ross <14985050+R055A@users.noreply.github.com>
Date: Thu, 19 Oct 2023 20:13:41 +0200
Subject: [PATCH 1/2] Feat(maths): add matrix multiplication
---
DIRECTORY.md | 1 +
maths/matrix_multiplication.ts | 44 ++++++
maths/test/matrix_multiplication.test.ts | 170 +++++++++++++++++++++++
3 files changed, 215 insertions(+)
create mode 100644 maths/matrix_multiplication.ts
create mode 100644 maths/test/matrix_multiplication.test.ts
diff --git a/DIRECTORY.md b/DIRECTORY.md
index 3237c4e5..710a5a7f 100644
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@@ -111,6 +111,7 @@
* [Is Square Free](https://github.com/TheAlgorithms/TypeScript/blob/HEAD/maths/is_square_free.ts)
* [Juggler Sequence](https://github.com/TheAlgorithms/TypeScript/blob/HEAD/maths/juggler_sequence.ts)
* [Lowest Common Multiple](https://github.com/TheAlgorithms/TypeScript/blob/HEAD/maths/lowest_common_multiple.ts)
+ * [Matrix Multiplication](https://github.com/TheAlgorithms/TypeScript/blob/HEAD/maths/matrix_multiplication.ts)
* [Number Of Digits](https://github.com/TheAlgorithms/TypeScript/blob/HEAD/maths/number_of_digits.ts)
* [Pascals Triangle](https://github.com/TheAlgorithms/TypeScript/blob/HEAD/maths/pascals_triangle.ts)
* [Perfect Cube](https://github.com/TheAlgorithms/TypeScript/blob/HEAD/maths/perfect_cube.ts)
diff --git a/maths/matrix_multiplication.ts b/maths/matrix_multiplication.ts
new file mode 100644
index 00000000..b2dfadcb
--- /dev/null
+++ b/maths/matrix_multiplication.ts
@@ -0,0 +1,44 @@
+/**
+ * @function matrixMultiplication
+ * @description Multiply a matrix with either another matrix, a vector or a scalar
+ * @param {Number[][]} matA - An array of an array of numbers
+ * @param {Number[][] | Number[] | Number} b - Either an array of an array of numbers, an array of numbers, or a number
+ * @return {Number[][] | Number[]} - Either an array of an array of numbers, or an array of numbers
+ * @example matrixMultiplication([[1, 2], [3, 4]], [[1, 2], [3, 4]]) = [[7, 10], [15, 22]]
+ * @example GreatestCommonFactor([[1, 2], [3, 4]], 2) = [[2, 4], [6, 8]]
+ * @example GreatestCommonFactor([[1, 2], [3, 4]], [1, 2]) = [5, 11]
+ */
+
+function matrixMultiplication(matA: number[][], b: number[][]): number[][];
+function matrixMultiplication(matA: number[][], b: number): number[][];
+function matrixMultiplication(matA: number[][], b: number[]): number[];
+
+function matrixMultiplication(matA: number[][], b: any): Number[][] | Number[] | null {
+ let matC: any = null;
+
+ if (typeof b === 'number') {
+ matC = matA.map(row => row.map(colVal => colVal * b));
+ } else {
+ if (matA[0].length !== b.length) {
+ return null;
+ }
+
+ if (typeof b[0] === 'number') {
+ matC = matA.map(row => row.reduce((sum, colVal, i) => sum + colVal * b[i], 0));
+ } else {
+ matC = new Array(matA.length).fill(null).map(() => new Array(b[0].length).fill(0));
+ let i: number, j: number, k: number;
+
+ for (i = 0; i < matA.length; i++) {
+ for (j = 0; j < b[0].length; j++) {
+ for (k = 0; k < matA[0].length; k++) {
+ matC[i][j] += matA[i][k] * b[k][j];
+ }
+ }
+ }
+ }
+ }
+ return matC;
+}
+
+export { matrixMultiplication };
diff --git a/maths/test/matrix_multiplication.test.ts b/maths/test/matrix_multiplication.test.ts
new file mode 100644
index 00000000..dbec6cb8
--- /dev/null
+++ b/maths/test/matrix_multiplication.test.ts
@@ -0,0 +1,170 @@
+import { matrixMultiplication } from '../matrix_multiplication';
+
+describe('Matrix-matrix multiplication', () => {
+ it.each([
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [
+ [7, 10],
+ [15, 22]
+ ]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [
+ [4, 3],
+ [2, 1]
+ ],
+ [
+ [8, 5],
+ [20, 13]
+ ]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [
+ [-1, 3],
+ [2, -4]
+ ],
+ [
+ [3, -5],
+ [5, -7]
+ ]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [
+ [1, 2]
+ ],
+ null
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [
+ [1, 2],
+ [3, 4],
+ [5, 6]
+ ],
+ null
+ ],
+ ])('Multiplying %j with %j should return %j', (matA, matB, expected) => {
+ expect(matrixMultiplication(matA, matB)).toEqual(expected);
+ });
+});
+
+describe('Matrix-scalar multiplication', () => {
+ it.each([
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ 0,
+ [
+ [0, 0],
+ [0, 0]
+ ]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ 1,
+ [
+ [1, 2],
+ [3, 4]
+ ]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ 2,
+ [
+ [2, 4],
+ [6, 8]
+ ]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ -3,
+ [
+ [-3, -6],
+ [-9, -12]
+ ]
+ ],
+ ])('Multiplying %j with %i should return %j', (matA, scalar, expected) => {
+ expect(matrixMultiplication(matA, scalar)).toEqual(expected);
+ });
+});
+
+describe('Matrix-vector multiplication', () => {
+ it.each([
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [1, 2],
+ [5, 11]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [3, 4],
+ [11, 25]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [-1, 0],
+ [-1, -3]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [1],
+ null
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [1, 2, 3],
+ null
+ ],
+ ])('Multiplying %j with %j should return %j', (matA, vector, expected) => {
+ expect(matrixMultiplication(matA, vector)).toEqual(expected);
+ });
+});
From f22d0960d266473d1270122760852ef7241370e5 Mon Sep 17 00:00:00 2001
From: Adam Ross <14985050+R055A@users.noreply.github.com>
Date: Thu, 19 Oct 2023 20:27:24 +0200
Subject: [PATCH 2/2] Refactor maths/matrix_multiplication tabbing
---
maths/matrix_multiplication.ts | 40 +--
maths/test/matrix_multiplication.test.ts | 320 +++++++++++------------
2 files changed, 180 insertions(+), 180 deletions(-)
diff --git a/maths/matrix_multiplication.ts b/maths/matrix_multiplication.ts
index b2dfadcb..78b861aa 100644
--- a/maths/matrix_multiplication.ts
+++ b/maths/matrix_multiplication.ts
@@ -14,31 +14,31 @@ function matrixMultiplication(matA: number[][], b: number): number[][];
function matrixMultiplication(matA: number[][], b: number[]): number[];
function matrixMultiplication(matA: number[][], b: any): Number[][] | Number[] | null {
- let matC: any = null;
+ let matC: any = null;
- if (typeof b === 'number') {
- matC = matA.map(row => row.map(colVal => colVal * b));
- } else {
- if (matA[0].length !== b.length) {
- return null;
- }
+ if (typeof b === 'number') {
+ matC = matA.map(row => row.map(colVal => colVal * b));
+ } else {
+ if (matA[0].length !== b.length) {
+ return null;
+ }
- if (typeof b[0] === 'number') {
- matC = matA.map(row => row.reduce((sum, colVal, i) => sum + colVal * b[i], 0));
- } else {
- matC = new Array(matA.length).fill(null).map(() => new Array(b[0].length).fill(0));
- let i: number, j: number, k: number;
+ if (typeof b[0] === 'number') {
+ matC = matA.map(row => row.reduce((sum, colVal, i) => sum + colVal * b[i], 0));
+ } else {
+ matC = new Array(matA.length).fill(null).map(() => new Array(b[0].length).fill(0));
+ let i: number, j: number, k: number;
- for (i = 0; i < matA.length; i++) {
- for (j = 0; j < b[0].length; j++) {
- for (k = 0; k < matA[0].length; k++) {
- matC[i][j] += matA[i][k] * b[k][j];
- }
- }
- }
+ for (i = 0; i < matA.length; i++) {
+ for (j = 0; j < b[0].length; j++) {
+ for (k = 0; k < matA[0].length; k++) {
+ matC[i][j] += matA[i][k] * b[k][j];
+ }
}
+ }
}
- return matC;
+ }
+ return matC;
}
export { matrixMultiplication };
diff --git a/maths/test/matrix_multiplication.test.ts b/maths/test/matrix_multiplication.test.ts
index dbec6cb8..4c869f2a 100644
--- a/maths/test/matrix_multiplication.test.ts
+++ b/maths/test/matrix_multiplication.test.ts
@@ -1,170 +1,170 @@
import { matrixMultiplication } from '../matrix_multiplication';
describe('Matrix-matrix multiplication', () => {
- it.each([
- [
- [
- [1, 2],
- [3, 4]
- ],
- [
- [1, 2],
- [3, 4]
- ],
- [
- [7, 10],
- [15, 22]
- ]
- ],
- [
- [
- [1, 2],
- [3, 4]
- ],
- [
- [4, 3],
- [2, 1]
- ],
- [
- [8, 5],
- [20, 13]
- ]
- ],
- [
- [
- [1, 2],
- [3, 4]
- ],
- [
- [-1, 3],
- [2, -4]
- ],
- [
- [3, -5],
- [5, -7]
- ]
- ],
- [
- [
- [1, 2],
- [3, 4]
- ],
- [
- [1, 2]
- ],
- null
- ],
- [
- [
- [1, 2],
- [3, 4]
- ],
- [
- [1, 2],
- [3, 4],
- [5, 6]
- ],
- null
- ],
- ])('Multiplying %j with %j should return %j', (matA, matB, expected) => {
- expect(matrixMultiplication(matA, matB)).toEqual(expected);
- });
+ it.each([
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [
+ [7, 10],
+ [15, 22]
+ ]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [
+ [4, 3],
+ [2, 1]
+ ],
+ [
+ [8, 5],
+ [20, 13]
+ ]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [
+ [-1, 3],
+ [2, -4]
+ ],
+ [
+ [3, -5],
+ [5, -7]
+ ]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [
+ [1, 2]
+ ],
+ null
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [
+ [1, 2],
+ [3, 4],
+ [5, 6]
+ ],
+ null
+ ],
+ ])('Multiplying %j with %j should return %j', (matA, matB, expected) => {
+ expect(matrixMultiplication(matA, matB)).toEqual(expected);
+ });
});
describe('Matrix-scalar multiplication', () => {
- it.each([
- [
- [
- [1, 2],
- [3, 4]
- ],
- 0,
- [
- [0, 0],
- [0, 0]
- ]
- ],
- [
- [
- [1, 2],
- [3, 4]
- ],
- 1,
- [
- [1, 2],
- [3, 4]
- ]
- ],
- [
- [
- [1, 2],
- [3, 4]
- ],
- 2,
- [
- [2, 4],
- [6, 8]
- ]
- ],
- [
- [
- [1, 2],
- [3, 4]
- ],
- -3,
- [
- [-3, -6],
- [-9, -12]
- ]
- ],
- ])('Multiplying %j with %i should return %j', (matA, scalar, expected) => {
- expect(matrixMultiplication(matA, scalar)).toEqual(expected);
- });
+ it.each([
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ 0,
+ [
+ [0, 0],
+ [0, 0]
+ ]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ 1,
+ [
+ [1, 2],
+ [3, 4]
+ ]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ 2,
+ [
+ [2, 4],
+ [6, 8]
+ ]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ -3,
+ [
+ [-3, -6],
+ [-9, -12]
+ ]
+ ],
+ ])('Multiplying %j with %i should return %j', (matA, scalar, expected) => {
+ expect(matrixMultiplication(matA, scalar)).toEqual(expected);
+ });
});
describe('Matrix-vector multiplication', () => {
- it.each([
- [
- [
- [1, 2],
- [3, 4]
- ],
- [1, 2],
- [5, 11]
- ],
- [
- [
- [1, 2],
- [3, 4]
- ],
- [3, 4],
- [11, 25]
- ],
- [
- [
- [1, 2],
- [3, 4]
- ],
- [-1, 0],
- [-1, -3]
- ],
- [
- [
- [1, 2],
- [3, 4]
- ],
- [1],
- null
- ],
- [
- [
- [1, 2],
- [3, 4]
- ],
- [1, 2, 3],
- null
- ],
- ])('Multiplying %j with %j should return %j', (matA, vector, expected) => {
- expect(matrixMultiplication(matA, vector)).toEqual(expected);
- });
+ it.each([
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [1, 2],
+ [5, 11]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [3, 4],
+ [11, 25]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [-1, 0],
+ [-1, -3]
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [1],
+ null
+ ],
+ [
+ [
+ [1, 2],
+ [3, 4]
+ ],
+ [1, 2, 3],
+ null
+ ],
+ ])('Multiplying %j with %j should return %j', (matA, vector, expected) => {
+ expect(matrixMultiplication(matA, vector)).toEqual(expected);
+ });
});