Tensorflow.js tf.callbacks.earlyStopping() Function

import * as tf from "@tensorflow/tfjs";

const xArray = [
    [1, 2, 3, 4],
    [5, 6, 7, 8],
    [8, 7, 6, 5],
    [1, 2, 3, 4],
];

const x1Array = [
    [0, 1, 0.5, 0],
    [1, 0.5, 0, 1],
    [0.5, 1, 1, 0],
    [1, 0, 0, 1],
];

const yArray = [1, 2, 3, 4];
const y1Array = [4, 3, 2, 1];

// Create a dataset from the JavaScript array.
const xDataset = tf.data.array(xArray);
const x1Dataset = tf.data.array(x1Array);
const y1Dataset = tf.data.array(x1Array);
const yDataset = tf.data.array(yArray);

// Combining the Dataset with zip function
const xyDataset = tf.data
    .zip({ xs: xDataset, ys: yDataset })
    .batch(4)
    .shuffle(4);
const xy1Dataset = tf.data
    .zip({ xs: x1Dataset, ys: y1Dataset })
    .batch(4)
    .shuffle(4);

// Creating model
const model = tf.sequential();
model.add(
    tf.layers.dense({
        units: 1,
        inputShape: [4],
    })
);

// Compiling model
model.compile({ loss: "meanSquaredError", 
    optimizer: "sgd", metrics: ["acc"] });

// Using tf.callbacks.earlyStopping in fitDataset.
const history = await model.fitDataset(xyDataset, {
    epochs: 10,
    validationData: xy1Dataset,
    callbacks: tf.callbacks.earlyStopping({ 
        monitor: "val_acc" }),
});

// Printing value
console.log("The value of val_acc is :", 
    history.history.val_acc);

import * as tf from "@tensorflow/tfjs";

// Creating tensor for training
const x = tf.tensor([5, 6, 7, 8, 9, 2], [3, 2]);
const x1 = tf.tensor([8, 7, 6, 5, 2, 9], [3, 2]);
const y = tf.tensor([1, 3, 3, 4, 4, 6, 6, 8, 9], [3, 3]);
const y1 = tf.tensor([2, 2, 2, 1, 5, 5, 2, 3, 8], [3, 3]);

// Creating model
const model = tf.sequential();

model.add(
    tf.layers.dense({
        units: 3,
        inputShape: [2],
    })
);

// Compiling model
model.compile({ loss: "meanSquaredError", 
    optimizer: "sgd", metrics: ["acc"] });

// Using tf.callbacks.earlyStopping in fit.
const history = await model.fit(x, y, {
    epochs: 10,
    validationData: [x1, y1],
    callbacks: tf.callbacks.earlyStopping({ 
        monitor: "val_acc" }),
});

// Printing value
console.log("the value of val_acc is :", 
    history.history.val_acc);