---
title: "MultinomialNB in JavaScript with @kanaries/ml"
description: "Classify non-negative count features with the MultinomialNB JavaScript and TypeScript implementation in @kanaries/ml."
canonical_url: "https://ml.kanaries.net/docs/apis/bayes/multinomialNB"
markdown_url: "https://ml.kanaries.net/docs/apis/bayes/multinomialNB.md"
---
# MultinomialNB in JavaScript

## Algorithm overview

MultinomialNB is a naive Bayes classifier for non-negative feature counts, such as token counts or frequency-style encoded data.

## JavaScript implementation

`@kanaries/ml` provides `Bayes.MultinomialNB` for JavaScript and TypeScript applications that need fast probabilistic classification without leaving the browser or Node.js runtime.

## Quick start example

```ts
import { Bayes } from '@kanaries/ml';

const X = [[2, 0, 1], [1, 0, 2], [0, 2, 1], [0, 3, 1]];
const y = [0, 0, 1, 1];

const clf = new Bayes.MultinomialNB({ alpha: 1.0 });
clf.fit(X, y);
const pred = clf.predict([[1, 0, 1], [0, 2, 2]]);
console.log(pred);
```

## Detailed API reference

```ts
new Bayes.MultinomialNB(props?: {
  alpha?: number;
  forceAlpha?: boolean;
  fitPrior?: boolean;
  classPrior?: number[] | null;
})
```

Methods:

- `fit(X: number[][], y: number[]): void`
- `predict(X: number[][]): number[]`

Feature values must be non-negative.