/**
 * @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/engine/training_tensors" />
import { Tensor, Tensor1D } from '@tensorflow/tfjs-core';
import { BaseCallback, CustomCallbackArgs, ModelLoggingVerbosity, YieldEveryOptions } from '../base_callbacks';
import { ClassWeight, ClassWeightMap } from './training_utils';
/**
 * Interface configuration model training based on data as `tf.Tensor`s.
 */
export interface ModelFitArgs {
    /**
     * Number of samples per gradient update. If unspecified, it
     * will default to 32.
     */
    batchSize?: number;
    /**
     * Integer number of times to iterate over the training data arrays.
     */
    epochs?: number;
    /**
     * Verbosity level.
     *
     * Expected to be 0, 1, or 2. Default: 1.
     *
     * 0 - No printed message during fit() call.
     * 1 - In Node.js (tfjs-node), prints the progress bar, together with
     *     real-time updates of loss and metric values and training speed.
     *     In the browser: no action. This is the default.
     * 2 - Not implemented yet.
     */
    verbose?: ModelLoggingVerbosity | 2;
    /**
     * List of callbacks to be called during training.
     * Can have one or more of the following callbacks:
     *   - `onTrainBegin(logs)`: called when training starts.
     *   - `onTrainEnd(logs)`: called when training ends.
     *   - `onEpochBegin(epoch, logs)`: called at the start of every epoch.
     *   - `onEpochEnd(epoch, logs)`: called at the end of every epoch.
     *   - `onBatchBegin(batch, logs)`: called at the start of every batch.
     *   - `onBatchEnd(batch, logs)`: called at the end of every batch.
     *   - `onYield(epoch, batch, logs)`: called every `yieldEvery` milliseconds
     *      with the current epoch, batch and logs. The logs are the same
     *      as in `onBatchEnd()`. Note that `onYield` can skip batches or
     *      epochs. See also docs for `yieldEvery` below.
     */
    callbacks?: BaseCallback[] | CustomCallbackArgs | CustomCallbackArgs[];
    /**
     * Float between 0 and 1: fraction of the training data
     * to be used as validation data. The model will set apart this fraction of
     * the training data, will not train on it, and will evaluate the loss and
     * any model metrics on this data at the end of each epoch.
     * The validation data is selected from the last samples in the `x` and `y`
     * data provided, before shuffling.
     */
    validationSplit?: number;
    /**
     * Data on which to evaluate the loss and any model
     * metrics at the end of each epoch. The model will not be trained on this
     * data. This could be a tuple [xVal, yVal] or a tuple [xVal, yVal,
     * valSampleWeights]. The model will not be trained on this data.
     * `validationData` will override `validationSplit`.
     */
    validationData?: [
        Tensor | Tensor[],
        Tensor | Tensor[]
    ] | [Tensor | Tensor[], Tensor | Tensor[], Tensor | Tensor[]];
    /**
     * Whether to shuffle the training data before each epoch. Has
     * no effect when `stepsPerEpoch` is not `null`.
     */
    shuffle?: boolean;
    /**
     * Optional object mapping class indices (integers) to
     * a weight (float) to apply to the model's loss for the samples from this
     * class during training. This can be useful to tell the model to "pay more
     * attention" to samples from an under-represented class.
     *
     * If the model has multiple outputs, a class weight can be specified for
     * each of the outputs by setting this field an array of weight object
     * or an object that maps model output names (e.g., `model.outputNames[0]`)
     * to weight objects.
     */
    classWeight?: ClassWeight | ClassWeight[] | ClassWeightMap;
    /**
     * Optional array of the same length as x, containing
     * weights to apply to the model's loss for each sample. In the case of
     * temporal data, you can pass a 2D array with shape (samples,
     * sequenceLength), to apply a different weight to every timestep of every
     * sample. In this case you should make sure to specify
     * sampleWeightMode="temporal" in compile().
     */
    sampleWeight?: Tensor;
    /**
     * Epoch at which to start training (useful for resuming a previous training
     * run). When this is used, `epochs` is the index of the "final epoch".
     * The model is not trained for a number of iterations given by `epochs`,
     * but merely until the epoch of index `epochs` is reached.
     */
    initialEpoch?: number;
    /**
     * Total number of steps (batches of samples) before
     * declaring one epoch finished and starting the next epoch. When training
     * with Input Tensors such as TensorFlow data tensors, the default `null` is
     * equal to the number of unique samples in your dataset divided by the
     * batch size, or 1 if that cannot be determined.
     */
    stepsPerEpoch?: number;
    /**
     * Only relevant if `stepsPerEpoch` is specified. Total number of steps
     * (batches of samples) to validate before stopping.
     */
    validationSteps?: number;
    /**
     * Configures the frequency of yielding the main thread to other tasks.
     *
     * In the browser environment, yielding the main thread can improve the
     * responsiveness of the page during training. In the Node.js environment,
     * it can ensure tasks queued in the event loop can be handled in a timely
     * manner.
     *
     * The value can be one of the following:
     *   - `'auto'`: The yielding happens at a certain frame rate (currently set
     *               at 125ms). This is the default.
     *   - `'batch'`: yield every batch.
     *   - `'epoch'`: yield every epoch.
     *   - any `number`: yield every `number` milliseconds.
     *   - `'never'`: never yield. (yielding can still happen through `await
     *      nextFrame()` calls in custom callbacks.)
     */
    yieldEvery?: YieldEveryOptions;
}
export declare function checkBatchSize(batchSize: number): void;
/**
 * Slice a Tensor or an Array of Tensors, by start and stop indices.
 *
 * Porting Note: The `_slice_arrays` function in PyKeras is covered by this
 *   function and `sliceArraysByIndices()` together.
 *
 * @param arrays: the input.
 * @param start: the starting index (inclusive).
 * @param stop: the stopping index (exclusive).
 * @returns The result of the slicing. If `arrays` is an `Array` of
 *   `tf.Tensor`s, the slicing will be applied to all elements of the `Array`
 *   in the same way.
 */
export declare function sliceArrays(arrays: Tensor | Tensor[], start: number, stop: number): Tensor | Tensor[];
/**
 * Slice a Tensor or an Array of Tensors, by random-order indices.
 *
 * Porting Note: The `_slice_arrays` function in PyKeras is covered by this
 *   function and `sliceArrays()` together.
 *
 * @param arrays The input `tf.Tensor` or `Array` of `tf.Tensor`s to slice.
 *   If an `Array` of `tf.Tensor`s, all `tf.Tensor`s will be sliced in the
 *   same fashion.
 * @param indices The indices to use for slicing along the first (batch)
 *   dimension.
 * @returns Result(s) of the slicing.
 */
export declare function sliceArraysByIndices(arrays: Tensor | Tensor[], indices: Tensor1D): Tensor | Tensor[];
/**
 * Returns a list of batch indices (tuples of indices).
 * @param size: Integer, total size of the data to slice into batches.
 * @param batchSize: Integer, batch size.
 * @returns An Array of [batchStart, batchEnd] tuples. batchStart is
 *   inclusive; batchEnd is exclusive. I.e., each batch consists of indices x
 *   that satisfy batchStart <= x < batchEnd.
 */
export declare function makeBatches(size: number, batchSize: number): Array<[number, number]>;
/**
 * Ensure tensors all have a rank of at least 2.
 *
 * If a tensor has a rank of 1, it is dimension-expanded to rank 2.
 * If any tensor has a rank of 0 (i.e., is a scalar), an error will be thrown.
 */
export declare function ensureTensorsRank2OrHigher(tensors: Tensor | Tensor[]): Tensor[];
/**
 * Compare a set of tensors with a reference (old) set, discard the ones
 * in the new set that are not present in the reference set.
 *
 * This method is used for memory clenaup during calls such as
 * LayersModel.fit().
 *
 * @param tensors New set which may contain Tensors not present in
 *   `refTensors`.
 * @param refTensors Reference Tensor set.
 */
export declare function disposeNewTensors(tensors: Tensor | Tensor[] | {
    [inputName: string]: Tensor;
}, refTensors: Tensor | Tensor[] | {
    [inputName: string]: Tensor;
}): void;