# número

A friendly and intuitive math library for p5.js

This p5.js addon library provides a beginner-friendly `Tensor` class that's similar to a NumPy array. It builds on the linear algebra engine from TensorFlow.js and adapts it for sketching. You can view número's source code along with examples on GitHub.

## Usage

número's `Tensor` class is a generalization of numbers (scalars), vectors, and matrices. `Tensor`s are used heavily in fields ranging from physics to machine learning. Here are a few examples of `Tensor`s you may recognize:

``````// The age of a cat in years.// Rank-0 (Scalar)let age = createTensor(5);// The position of a cat in space.// Rank-1 (Vector)let position = createTensor([10, 20, 30]);// The grayscale values of the pixels in a 2x2 cat picture.// Rank-2 (Matrix)let grayscale = createTensor([[100, 187],                              [123, 182]]);// The RGB values of the pixels in a 2x2 cat picture.// Rank-3 (Array of Matrices)let rgb = createTensor([                        // Red.                        [[100, 187],                        [123, 182]],                        // Green.                        [[80, 205],                        [20, 133]],                        // Blue.                        [[201, 72],                        [209, 247]],                      ]);
``````

The following example multiplies a rank-1 `Tensor` (vector) by a rank-2 `Tensor` (matrix):

``````function setup() {  createCanvas(400, 400);  background(220);  // Translate the origin to the center.  translate(200, 200);    // Create the rotation matrix.  let R = createTensor([[cos(HALF_PI), -sin(HALF_PI)],                        [sin(HALF_PI), cos(HALF_PI)]]);  // Create the vector.  let v = createTensor([100, 0]);  // Get the vector's components.  let [x1, y1] = v.arraySync();  // Draw the vector in red.  stroke('red');  line(0, 0, x1, y1);  // Rotate the vector using matrix-vector multiplication,  // also called the "inner" or "dot" product.  v = R.dot(v);  // Get the rotated vector's components.  let [x2, y2] = v.arraySync();  // Draw the rotated vector in blue.  stroke('blue');  line(0, 0, x2, y2);  describe('Two lines extend from the center of a gray square. A red line extends to the right. A blue line extends downward.');}
``````

## Contributing

See CONTRIBUTING.

## Contributors ✨

Thanks goes to these wonderful people (emoji key):

This project follows the all-contributors specification. Contributions of any kind welcome!