Dataset examples¶

The most basic dataset implementation is an array. Both NumPy and CuPy arrays can be used directly as datasets.

In many cases, though, the simple arrays are not enough to write the training procedure. In order to cover most of such cases, Chainer provides many built-in implementations of datasets.

These built-in datasets are divided into two groups. One is a group of general datasets. Most of them are wrapper of other datasets to introduce some structures (e.g., tuple or dict) to each data point. The other one is a group of concrete, popular datasets. These concrete examples use the downloading utilities in the chainer.dataset module to cache downloaded and converted datasets.

General datasets¶

General datasets are further divided into three types.

The first one is DictDataset and TupleDataset, both of which combine other datasets and introduce some structures on them.

The second one is SubDataset, which represents a subset of an existing dataset. It can be used to separate a dataset for hold-out validation or cross validation. Convenient functions to make random splits are also provided.

The third one is TransformDataset, which wraps around a dataset by applying a function to data indexed from the underlying dataset. It can be used to modify behavior of a dataset that is already prepared.

The last one is a group of domain-specific datasets. Currently, ImageDataset and LabeledImageDataset are provided for datasets of images.

DictDataset¶

chainer.datasets.DictDataset Dataset of a dictionary of datasets.

TupleDataset¶

chainer.datasets.TupleDataset Dataset of a tuple of datasets.

SubDataset¶

`chainer.datasets.SubDataset`	Subset of a base dataset.
`chainer.datasets.split_dataset`	Splits a dataset into two subsets.
`chainer.datasets.split_dataset_random`	Splits a dataset into two subsets randomly.
`chainer.datasets.get_cross_validation_datasets`	Creates a set of training/test splits for cross validation.
`chainer.datasets.get_cross_validation_datasets_random`	Creates a set of training/test splits for cross validation randomly.

TransformDataset¶

chainer.datasets.TransformDataset Dataset that indexes the base dataset and transforms the data.

ImageDataset¶

chainer.datasets.ImageDataset Dataset of images built from a list of paths to image files.

LabeledImageDataset¶

chainer.datasets.LabeledImageDataset Dataset of image and label pairs built from a list of paths and labels.

Concrete datasets¶

`chainer.datasets.get_mnist`	Gets the MNIST dataset.
`chainer.datasets.get_cifar10`	Gets the CIFAR-10 dataset.
`chainer.datasets.get_cifar100`	Gets the CIFAR-100 dataset.
`chainer.datasets.get_ptb_words`	Gets the Penn Tree Bank dataset as long word sequences.
`chainer.datasets.get_ptb_words_vocabulary`	Gets the Penn Tree Bank word vocabulary.