MNIST Neural Network in C

This source code seeks to replicate the (now removed) MNIST For ML Beginners tutorial from the Tensorflow website using plain C code.

The task is to recognise digits, such as the ones below, as accurately as possible.

By AndrewCarterUK

Contents

• mnist.c: Glue code that runs the algorithm steps and reports algorithm accuracy
• mnist_file.c: Retrieves images and labels from the MNIST dataset
• neural_network.c: Implements training and prediction routines for a simple neural network

Usage

make
./mnist

Description

The neural network implemented has one output layer and no hidden layers. Softmax activation is used, and this ensures that the output activations form a probability vector corresponding to each label. The cross entropy is used as a loss function.

The algorithm reaches an accuracy of around 92% over 1000 steps.

Expected Output

Step 0000   Average Loss: 4.36  Accuracy: 0.152
Step 0001   Average Loss: 3.42  Accuracy: 0.188
Step 0002   Average Loss: 2.97  Accuracy: 0.298
Step 0003   Average Loss: 2.53  Accuracy: 0.319
Step 0004   Average Loss: 2.19  Accuracy: 0.412
Step 0005   Average Loss: 2.08  Accuracy: 0.437
Step 0006   Average Loss: 1.73  Accuracy: 0.468
Step 0007   Average Loss: 1.51  Accuracy: 0.447
Step 0008   Average Loss: 1.57  Accuracy: 0.496
Step 0009   Average Loss: 1.45  Accuracy: 0.516
Step 0010   Average Loss: 1.78  Accuracy: 0.559
...