# Bindings for CNTK library

Simple low level bindings for [CNTK library](https://github.com/Microsoft/CNTK/blob/release/2.2/Source/CNTKv2LibraryDll/API/CNTKLibrary.h) from Microsoft.

## Status

Currently exploring ways how to interact with C++ API nicely from Rust.
Expect a lot of breaking changes.

Build scripts are not ready yet, might not work outside of 64bit linux.

## Goals

* Ability to train all reasonable architectures
* No memory leaks
* Reasonable ease of use

## Nongoals

* Idiomatic Rust everywhere
* Super good ergonomics
* Avoiding all unnecessary copies

## Building and installing

You need to have CNTK-2.3 installed and paths to includes and library files in
relevant enviroment variables (cntk activate scripts does this well).
You also need g++-4.8 installed (because CNTK uses it to compile things).

## Example usage

See [examples](https://github.com/usamec/cntk-rs/tree/master/examples) folder.

## Other limitations

Only works with single precision (f32 in Rust, float in C++) types.
Only works with dense representations of vectors/matrices/tensors.
Only works with ASCII strings for variable names and filenames.

## What works

* Passing data in and out of computation.
* Backpropagation.
* Training fully connected feedforward, convolutional and recurrent network.
* Saving and loading the model.
* Code for most operations. - Almost all, except couple of helpers.
* Demo of seq2seq model training.
* Turning c++ exception into rust panics (most of the time).
* Interop with NDArray library.

## Planned in future

* GPU.
* Better docs.
* Finish all operations.
* Better build scripts.
* Figure out whether we want NDArrayView or go directly from Rust data to Value and back.
* Builder pattern where appropriate (Variable?).