Matrix library for C++20

A tiny C++20 general-purpose library for dense, fixed-size and dynamically-sized matrices with no dependencies.

Overview

Features:

• intuitive syntax
• low-overhead
• header-only and single-header
• fully constexpr (except where math functions like `sqrt` are used).
• STL-oriented
• Statically-sized have static memory (e.g. suited for audio development).
• Dynamically-sized matrices are now available as well.
• simple software design in comparison to some other matrix libs, e.g. no CRTP, virtual functions, ...
• fully tested. Tests can be run with Catch2.

Limitations:

• only C++20 (and up) because of heavy use of concepts and constexpr
• this is not a linear algebra library - at the moment the library provides no linear algebra algorithms such as decomposition and solvers

Sample Code (some possible operations)

Matrix<float, 3, 3> mat{ 1,2,3,4,5,6,7,8,9 };
auto mat2 = mat * 2.f - mat;

// Take sqrt of all entries
mat.apply([](float& f) {f = std::sqrtf(f); });

// Iterate over all entries (row first)
for (const auto& el : mat) {}
// Iterate over one row
for (const auto& el : mat.row(1)) {}
// Copy one row into another
mat.row(1) = mat.row(0);
// Copy matrix block into other matrix
mat2.block(1, 1, 2, 2) = mat.block(0, 0, 2, 2);

Vector3f vec = mat.col(0);
vec.x() += 5;
float norm = vec.norm();

RowVector3f row_vec(7);
// Auto cast 1x1 matrix to scalar
float scalar = row_vec * vec; 

// Pretty print matrices
cout << mat << mat2 << vec;

// Dynamic matrices
Matrix<float, dynamic, dynamic> dyn_mat{ 3, 4 };

Documentation

Documentation overview

• Classes
• Type Definitions
• Predefined Matrices
• Exceptions (optional)
• Matrix Class
  • Template Parameters
  • Types
  • Constructors
  • Matrix Access
  • Arithmetic
  • Other Matrix Operations
  • Iterators
  • Row/Column/Block Access
  • Vector-specific Operations
  • Factory Functions
• Matrix_view Class
  • Types
  • Constructors
  • Iterators
  • Member Functions
• Global Functions

Classes

Type Definitions

Predefined Matrices

Exceptions

By default, exceptions are not activated. Calls to Matrix::block(Index, Index, Index, Index), Matrix::row(Index), Matrix::col(Index), Matrix_view::operator=(const Matrix_view&), Matrix_view::operator=(const Matrix&) and Matrix(const Matrix_view&) will do an assertation when running in debug mode. Defining the macro MATRIX_EXCEPTIONS before including this library will instead turn on exceptions for these cases.

Matrix Class

Matrix_view Class

Global Functions