/**
 * @license
 * Copyright 2018 Google LLC
 *
 * Use of this source code is governed by an MIT-style
 * license that can be found in the LICENSE file or at
 * https://opensource.org/licenses/MIT.
 * =============================================================================
 */
/// <amd-module name="@tensorflow/tfjs-layers/dist/callbacks" />
import { BaseCallback } from './base_callbacks';
import { Container } from './engine/container';
import { LayersModel } from './engine/training';
import { Logs } from './logs';
export declare abstract class Callback extends BaseCallback {
    /** Instance of `keras.models.Model`. Reference of the model being trained. */
    model: LayersModel;
    setModel(model: Container): void;
}
export interface EarlyStoppingCallbackArgs {
    /**
     * Quantity to be monitored.
     *
     * Defaults to 'val_loss'.
     */
    monitor?: string;
    /**
     * Minimum change in the monitored quantity to qualify as improvement,
     * i.e., an absolute change of less than `minDelta` will count as no
     * improvement.
     *
     * Defaults to 0.
     */
    minDelta?: number;
    /**
     * Number of epochs with no improvement after which training will be stopped.
     *
     * Defaults to 0.
     */
    patience?: number;
    /** Verbosity mode. */
    verbose?: number;
    /**
     * Mode: one of 'min', 'max', and 'auto'.
     * - In 'min' mode, training will be stopped when the quantity monitored has
     *   stopped decreasing.
     * - In 'max' mode, training will be stopped when the quantity monitored has
     *   stopped increasing.
     * - In 'auto' mode, the direction is inferred automatically from the name of
     *   the monitored quantity.
     *
     * Defaults to 'auto'.
     */
    mode?: 'auto' | 'min' | 'max';
    /**
     * Baseline value of the monitored quantity.
     *
     * If specified, training will be stopped if the model doesn't show
     * improvement over the baseline.
     */
    baseline?: number;
    /**
     * Whether to restore model weights from the epoch with the best value
     * of the monitored quantity. If `False`, the model weights obtained at the
     * last step of training are used.
     *
     * **`True` is not supported yet.**
     */
    restoreBestWeights?: boolean;
}
/**
 * A Callback that stops training when a monitored quantity has stopped
 * improving.
 */
export declare class EarlyStopping extends Callback {
    protected readonly monitor: string;
    protected readonly minDelta: number;
    protected readonly patience: number;
    protected readonly baseline: number;
    protected readonly verbose: number;
    protected readonly mode: 'auto' | 'min' | 'max';
    protected monitorFunc: (currVal: number, prevVal: number) => boolean;
    private wait;
    private stoppedEpoch;
    private best;
    constructor(args?: EarlyStoppingCallbackArgs);
    onTrainBegin(logs?: Logs): Promise<void>;
    onEpochEnd(epoch: number, logs?: Logs): Promise<void>;
    onTrainEnd(logs?: Logs): Promise<void>;
    private getMonitorValue;
}
/**
 * Factory function for a Callback that stops training when a monitored
 * quantity has stopped improving.
 *
 * Early stopping is a type of regularization, and protects model against
 * overfitting.
 *
 * The following example based on fake data illustrates how this callback
 * can be used during `tf.LayersModel.fit()`:
 *
 * ```js
 * const model = tf.sequential();
 * model.add(tf.layers.dense({
 *   units: 3,
 *   activation: 'softmax',
 *   kernelInitializer: 'ones',
 *   inputShape: [2]
 * }));
 * const xs = tf.tensor2d([1, 2, 3, 4], [2, 2]);
 * const ys = tf.tensor2d([[1, 0, 0], [0, 1, 0]], [2, 3]);
 * const xsVal = tf.tensor2d([4, 3, 2, 1], [2, 2]);
 * const ysVal = tf.tensor2d([[0, 0, 1], [0, 1, 0]], [2, 3]);
 * model.compile(
 *     {loss: 'categoricalCrossentropy', optimizer: 'sgd', metrics: ['acc']});
 *
 * // Without the EarlyStopping callback, the val_acc value would be:
 * //   0.5, 0.5, 0.5, 0.5, ...
 * // With val_acc being monitored, training should stop after the 2nd epoch.
 * const history = await model.fit(xs, ys, {
 *   epochs: 10,
 *   validationData: [xsVal, ysVal],
 *   callbacks: tf.callbacks.earlyStopping({monitor: 'val_acc'})
 * });
 *
 * // Expect to see a length-2 array.
 * console.log(history.history.val_acc);
 * ```
 *
 * @doc {
 *   heading: 'Callbacks',
 *   namespace: 'callbacks'
 * }
 */
export declare function earlyStopping(args?: EarlyStoppingCallbackArgs): EarlyStopping;
export declare const callbacks: {
    earlyStopping: typeof earlyStopping;
};