Naive hand-written digit recognition with display applications to show image, prediction, and errors.

This is a C# version of a project originally written in .NET (F# & C#). Details of that project are available here: https://github.com/jeremybytes/digit-display.

This is primarily used to compare performance and other environment features with similar projects in Go (golang) and Rust (rust-lang).

Functions

• Reading files from the file system
• Training simple nearest-neighbor digit recognizers
  • Manhattan distance
  • Euclidean distance
• Output (pretty bad) ASCII art
• Multi-threading
• Channels
• Chunking / threading
• Parsing command-line parameters

Usage

PS C:\...> .\digits.exe --help
digits 1.0.0
Copyright (C) 2022 digits

  -o, --offset     (Default: 1000) Offset in the data set (default: 1000)
  -c, --count      (Default: 100) Number of records to process (default: 100)
  --classifier     (Default: euclidean) Classifier to use (default: 'euclidean')
  -t, --threads    (Default: 6) Number of threads to use (default: 6)
  --help           Display this help screen.
  --version        Display version information.

Notes
This project was originally the slowest of the 3 (see https://github.com/jeremybytes/digit-display-language-comparison for comparison).

Based on community input, the following performance updates were made (details will be written up in articles soon):

• List<int> changed to int[]
• String concatenation changed from string+= to using StringBuilder
• Abstract override method was moved out of a tight loop to a higher level. This results in duplicated code but a very large change in performance.

These resulted in significant performance improvements. The first 2 changes resulted in run times that are 30% faster (from 20 seconds to 14 seconds for a specific run). All 3 changes together resulted in run times that are 75% faster (from 20 seconds to 5 seconds).

Branches
The original and updated code are available in separate branches for comparison purposes.

• original - includes the orginal code
• perftest1 - contains the array and string builder changes
• perftest2 - contains the abstract method changes

Specifics on these changes will be detailed soon.