Neurojure

Neurojure is a Clojure library for building, training, and testing neural network models using established architectures and optimization techniques. It uses Ranvier for optimization and Tensure for tensor computations.

Neurojure is a work-in-progress. It currently provides functions for implementing the following techniques:

• Deep feedforward networks
• Convolutional networks - the conv2d layer works on datasets of two spatial dimensions (width x height x channel)
• Recurrent networks - the recurrent and gru (gated recurrent unit) layers can be used to build deep recurrent networks
• Initialization - parameters can be initialized randomly over a variety of distributions
• Regularization - indvidual layers support options for regularization. Pass the final cost through the regularize layer during training to actually apply regularization. There is also a dropout layer.
• Common non-linearity and loss functions
• Encoding utilities - neurojure.senses has some utilities for preparing datasets for use in training networks--e.g. for fetching and caching datasets from the web, working with image data, generating one-hot encodings, tokenizing text, using word embeddings, etc.
• Robust optimization methods - With Ranvier, Neurojure networks can be trained using basic gradient descent and popular varients--gradient descent with momentum, RMSProp, and Adam

Getting Started

Add Neurojure to your dependencies. If using leiningen, add the following to your :dependencies in project.clj:

[neurojure "0.0.1"]

and require the core namespace:

(require '[neurojure.core :as nn])

Usage

The following snippet shows how to train a neurojure model to fit the xor function:

(require '[neurojure.core :as nn]
         '[ranvier.core :as r :refer [G]])

(r/set-rng-seed! 0)
(def naive-model
  (nn/make-model
    ; Models can contain named datasets; `:training`, `:dev`, and `:test` are common dataset names and are
    ; the defaults used by some functions. Here we include only one dataset, `:xor`, with three inputs,
    : `:a`, `:b`, and `:y`.
    :data {:xor {:a [1 1 0 0]
                 :b [1 0 1 0]
                 :y [0 1 1 0]}}
    ; This graph represents a very simple three-neuron network with logistic non-linearities for computing
    ; the xor function.
    :graph (G (-> (join-along 1
                              (reshape :a [4 1])
                              (reshape :b [4 1]))
                  (nn/dense {:units 2})
                  nn/logistic
                  (nn/dense {:units 1})
                  ; This will report the accuracy of our results during optimization.
                  (report (reshape :y [4 1])
                          (nn/make-binary-classifier-reporter)
                          (r/make-print-logger :space))
                  nn/logistic
                  ; The `:predicting` input is set to 1 (true) by default when we run `evaluate-model` below.
                  ; During training, it is set to 0 (false). When training, we compute cost. When predicting,
                  ; we apply a threshold.
                  (#(tensor-if :predicting
                               (> % 0.5)
                               (nn/binary-cross-entropy % (reshape :y [4 1]))))
                  (report (r/make-value-reporter "Cost") (r/make-print-logger :space))))
    :optimizer-options {:learning-rate 1
                        :report [:iteration]}))

(def trained-model (nn/train-model naive-model :xor 250))
;; Prints:
;;   Accuracy: 25.0%  Cost: 2.881609  Iteration: 1
;;   Accuracy: 50.0%  Cost: 2.810322  Iteration: 2
;;   .
;;   .
;;   .
;;   Accuracy: 100.0%  Cost: 0.096633025  Iteration: 249
;;   Accuracy: 100.0%  Cost: 0.09574343  Iteration: 250

(nn/evaluate-model trained-model :xor)
;; => #Tensure
;;    [0,
;;     1.0000,
;;     1.0000,
;;     0]

Examples

The examples directory contains a couple examples of using neurojure to solve more practical problems:

• mnist.clj - training a convolutional neural network to recognize handwritten digits
• book_reviews.clj - training a recurrent neural network to predict a user's rating of a book based on their written review

Documentation

The API docs have the details.

Contributing

Pull requests and ideas are welcome--please help!

License

Copyright © 2019 Casey Guenthner

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.