# Utilities¶

## Convolution/Deconvolution utilities¶

 chainer.utils.get_conv_outsize Calculates output size of convolution. chainer.utils.get_deconv_outsize Calculates output size of deconvolution.

## Common algorithms¶

 chainer.utils.WalkerAlias Implementation of Walker’s alias method.

## Common utilities¶

 chainer.print_runtime_info Shows Chainer runtime information.

## Reporter¶

 chainer.Reporter Object to which observed values are reported. chainer.get_current_reporter Returns the current reporter object. chainer.report Reports observed values with the current reporter object. chainer.report_scope Returns a report scope with the current reporter.

## Summary and DictSummary¶

 chainer.Summary Online summarization of a sequence of scalars. chainer.DictSummary Online summarization of a sequence of dictionaries.

## Sparse utilities¶

A chainer.Variable can be converted into a sparse matrix in e.g. COO (Coordinate list) format. A sparse matrix stores the same data as the original object but with a different internal representation, optimized for efficient operations on sparse data, i.e. data with many zero elements.

Following are a list of supported sparse matrix formats and utilities for converting between a chainer.Variable and these representations.

Note

Please be aware that only certain functions accept sparse matrices as inputs, such as chainer.functions.sparse_matmul().

 chainer.utils.CooMatrix A sparse matrix in COO format. chainer.utils.to_coo Returns a single or a batch of matrices in COO format.

## Experimental feature annotation¶

 chainer.utils.experimental Declares that user is using an experimental feature.