# easynn

This crate aims to provide neuro network developing and training utilities
in rust, where a variety of models and layers are supported.

Note: this crate is currently in beta, any interface is subject to change.

### Xor Example

Here we examine an example of building up a 3-layer MLP, learning the xor function of 64 bit integer.

```rust
    use easynn::prelude::*;
    use rand::Rng;

    // the target xor function
    let target_func = |x: u32, y: u32| { x ^ y };

    // create the network and add 4 layers
    let mut nn = Sequential::<f64>::new(Loss::MeanSquare);
    // add the input (2 integers) and a hidden layer
    nn.add(Dense::<f64>::new(sh!([2]), sh!([2, 32]), Activation::Relu));
    // add another hidden layer
    nn.add(Dense::<f64>::new(sh!([2, 32]), sh!([1000]), Activation::Relu));
    // add another hidden layer
    nn.add(Dense::<f64>::new(sh!([1000]), sh!([32]), Activation::Relu));
    // add the output layer
    nn.add(Dense::<f64>::new(sh!([32]), sh!([1]), Activation::Relu));

    // create the training set
    let mut rng = rand::thread_rng();
    let tot_samples: usize = 1000;
    let mut inputs = vec![Tensor::new(sh!([2]), vec![0_f64, 0_f64]); tot_samples];
    let mut outputs = vec![Tensor::new(sh!([1]), vec![0_f64]); tot_samples];
    for (i, o) in inputs.iter_mut().zip(outputs.iter_mut()) {
        let a = rng.gen::<u32>();
        let b = rng.gen::<u32>();
        i.set([0], a as f64);
        i.set([1], b as f64);
        o.set([0], target_func(a, b).into());
    }

    // train the model
    for _i in 0..10 {
        nn.train_once(&inputs, &outputs, 100, 0.1, false);
    }

    // evaluate the model
    let test_in1: u32 = 19260817;
    let test_in2: u32 = 1145141919;
    let test_out: u32 = target_func(test_in1, test_in2);
    let test_res = nn.predict(&Tensor::new(sh!([2]), vec![test_in1 as f64, test_in2 as f64])).unwrap().get([0]);
    println!("The prediction of input\n\t{:b} and\n\t{:b} is\n\t{:b} , expected\n\t{:b}"
        , test_in1, test_in2, test_res.floor() as u32, test_out);
```

### Supported models
 - [x] `Sequential`: similar to [The Sequential model](https://www.tensorflow.org/guide/keras/sequential_model) of [Keras](https://keras.io/)

### Supported layer types
 - Primitive types:
   - [x] `Dense`: fully connected layers
 - CNN types:
   - [ ] `Conv`: the convolution layer
   - [ ] `Pooling`: the pooling layer

License: MIT