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# npm

## matrix-js

1.6.0 • Public • Published

# matrix

A Javascript Library to perform basic matrix operations using the functional nature of Javascript

## Usage

```var a = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
var A = matrix(a);```

### Operations

#### 1. Identity

`A(); //returns [[1, 2, 3], [4, 5, 6], [7, 8, 9]]`

#### 2. Row

`A(0); // returns [1, 2, 3]`

#### 3. Column

`A([], 0); // returns [[1], [4], [7]]`

#### 4. Element

`A(1, 2); // returns 6`

#### 5. Range

```A([1,2]); // returns [[4, 5, 6], [7, 8, 9]]
A([],[1,2]); // returns [[2, 3], [5, 6], [8, 9]]
A([1,2],[1,2]); // returns [[5, 6], [8, 9]]
A([2,1],[]); // returns [[7, 8, 9], [4, 5 ,6]]
A([],[2,1]); // returns [[3, 2], [6, 5], [9, 8]]
A([2,1],[2,1]); // returns [[9, 8], [6, 5]]```

#### 6. Size

`A.size(); //returns [3, 3]`

#### 7. Set

```A.set(0).to(0); // returns [[0, 0, 0], [4, 5, 6], [7, 8, 9]]
A.set(1,2).to(10); // returns [[1, 2, 3], [4, 5, 10], [7, 8, 9]]
A.set([], 0).to(0); // returns [[0, 2, 3], [0, 5, 6], [0, 8, 9]]
A.set([1,2]).to(4); // returns [[1, 2, 3], [4, 4, 4], [4, 4, 4]]
A.set([], [1,2]).to(1); // returns [[1, 1, 1], [4, 1, 1], [7, 1, 1]]```

```var B = matrix([[3, 4, 5], [6, 7, 8], [9, 10, 11]]);
A.add(B); // returns [[4, 6, 8], [10, 12, 14], [16, 18, 20]]```

#### 9. Subtraction

`B.sub(A); // returns [[2, 2, 2], [2, 2, 2], [2, 2, 2]]`

#### 10. Multiplication

`A.mul(B); // returns [[3, 8, 15], [24, 35, 48], [56, 80, 99]]`

NOTE: This is not classical matrix multiplication (which is implemented using the prod() method). This simply multiplies together each element in matrix A with the corresponding element in matrix B. If A and B are not the same size, it will produce some NaN results.

#### 11. Division

`A.div(B); // returns [[0.33, 0.5, 0.6], [0.66, 0.71, 0.75], [0.77, 0.8, 0.81]]`

#### 12. Product

`A.prod(B); // returns [[42, 48, 54], [96, 111, 126], [150, 174, 198]]`

#### 13. Transpose

`A.trans(); // returns [[1, 4, 7], [2, 5, 8], [3, 6, 9]]`

#### 14. Determinant

```var C = matrix([[5, 4, 7], [4, 8, 2], [9, 0, 4]]);
C.det(); // returns -336```

#### 15. Inverse

Should be invertible

```M = matrix([[1, 3, 3], [1, 4, 3], [1, 3 ,4]]);
M.inv(); // returns [[7, -3, -3], [-1, 1, 0], [-1, 0 ,1]]```

#### 16. Merge

Merges two matrices in all directions

• Left
```M = matrix([[3, 4], [7, 8]]);
M.merge.left([[1, 2], [5, 6]]); // returns [[1, 2, 3, 4], [5, 6, 7, 8]]```
• Right
```M = matrix([[1, 2], [5, 6]]);
M.merge.right([[3, 4], [7, 8]]); // returns [[1, 2, 3, 4], [5, 6, 7, 8]]```
• Top
```M = matrix([5, 6, 7, 8]);
M.merge.top([1, 2, 3, 4]); // returns [[1, 2, 3, 4], [5, 6, 7, 8]]```
• Bottom
```M = matrix([1, 2, 3 ,4]);
M.merge.bottom([5, 6, 7, 8]); // returns [[1, 2, 3, 4], [5, 6, 7, 8]]```

#### 17. Map

Applies a given function over the matrix, elementwise. Similar to Array.map()

```M = matrix([1, 2, 3]);
M.map(x => x*x); // returns [1, 4, 9]```

This example shows the arguments provided to the function

```M = matrix([[1, 2], [3, 4]]);
M.map((value, pos, mat) => value * pos[1]);
// returns [[0, 2], [0, 4]]```

#### 18. Equals

Checks the equality of two matrices and returns a boolean. A matrix is equal to itself.

```A = matrix([[1,2],[3,4]]);
A.equals(A);
// returns true
B = matrix([[3,4], [1,2]]);
A.equals(B);
// returns false```

## Keywords

### Install

`npm i matrix-js`

### Repository

github.com/raghavgujjar/matrix

228

1.6.0

none

34.7 kB

8