61 lines
2.2 KiB
TypeScript

/**
* @license
* Copyright 2019 Google LLC. All Rights Reserved.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* =============================================================================
*/
import * as tf from '@tensorflow/tfjs-core';
/**
* A dataset for webcam controls which allows the user to add example Tensors
* for particular labels. This object will concat them into two large xs and ys.
*/
export class Dataset {
xs: tf.Tensor[];
ys: tf.Tensor;
constructor(public numClasses: number) {}
/**
* Adds an example to the controller dataset.
* @param {Tensor} example A tensor representing the example.
* It can be an image, an activation, or any other type of Tensor.
* @param {number} label The label of the example. Should be an number.
*/
addExample(example: tf.Tensor|tf.Tensor[], label: number) {
example = Array.isArray(example) ? example : [example];
// One-hot encode the label.
const y =
tf.tidy(() => tf.oneHot(tf.tensor1d([label]).toInt(), this.numClasses));
if (this.xs == null) {
// For the first example that gets added, keep example and y so that the
// Dataset owns the memory of the inputs. This makes sure that
// if addExample() is called in a tf.tidy(), these Tensors will not get
// disposed.
this.xs = example.map(tensor => tf.keep(tensor));
this.ys = tf.keep(y);
} else {
const oldX = this.xs;
this.xs = example.map(
(tensor, index) => tf.keep(this.xs[index].concat(tensor, 0)));
const oldY = this.ys;
this.ys = tf.keep(oldY.concat(y, 0));
oldX.forEach(tensor => tensor.dispose());
oldY.dispose();
y.dispose();
}
}
}