bachmeil / gretlmat

A simple linear algebra library for D

gretlmat

This library makes it as easy as possible to add matrix and vector support to a D program on Linux, Mac, or Windows.

Features

• Matrix and vector types.
• Operators for common operations like addition, subtraction, and multiplication.
• Support for common linear algebra operations.
• Vectors are ranges that support foreach.
• Rows and columns have their own types and are ranges that support foreach.
• Matrices can be used as ranges to iterate over rows or columns to support foreach.
• Multidimensional slicing provides convenient submatrix selection.

License

GPLv2

Design Constraints

• Optimized for ease of use rather than speed of execution.
• Full documentation, with a usage example for every feature.
• The entire library goes in one file. No dependencies other than Gretl.
• Works with any modern release of DMD, LDC, or GDC on any OS supported by D.
• No understanding of memory management required to use the library.
• No knowledge of C required to use the library.
• Code that's easy to read and extend with no more than an intermediate knowledge of D. Templates and metaprogramming might be great fun, but they can make the code hard to read and work with. They should be used only when it really is the simplest solution, and there should be comments in the code for someone that doesn't have that knowledge. This means there is lots of code duplication, and that's intentional. It is possible that I might remove some of the duplication if I can do so without making it hard to change the code.
• Stability - only bug fixes after the 1.0 release. It should be possible to use this library ten years in the future even if I make no updates. Users can write code knowing that it will work even if I disappear. In the extremely unlikely case that a change in the language itself breaks something, see the previous item. If I decide to make major changes, I'll start a new project with a new name - something I wish other projects would do.
• Compilation of programs with one simple line in the terminal. This reduces the need to learn new things, but there's a larger advantage. I can't guarantee stability (write code today and run it five years from now) if I rely on a build system that doesn't offer the same guarantee. Github will probably still be around in five years. The compiler will probably still compile programs the same way in five years. Gretl is heavily used and won't change the functionality I'm wrapping in the next five years.

Nongoals

• Optimize for speed of execution.
• Avoid the garbage collector.
• Demonstrate the power of the D programming language.
• Handle all use cases.
• Adoption outside of academic research and students.
• Non-GPL license. If for some reason the GPL bothers you, this is not the right library for you. Gretl is GPL and my code is not independent of the Gretl code. If you are selling a commercial product and do not want to release the source code under the GPL or a compatible license, don't use this library. If it's for your personal use, commercial or otherwise, the GPL lets you do whatever you want. I understand that some companies want a more freeloader-friendly license. I'm available for hire as a consultant if you want me to do related work under a different license.

Notes

• Currently under development
• Currently only tested on my own Ubuntu Linux setup
• Currently testing by running a test file and looking at the output