Eigen is a high-level C++ library of template headers for linear algebra, matrix and vector operations, numerical solvers, and related algorithms. It provides an expressive and efficient way to perform various mathematical operations, making it an essential tool for developers, researchers, and scientists. With Eigen, you can easily create and manipulate matrices, vectors, and tensors, and perform operations such as matrix multiplication, vector addition, and more. Eigen’s flexibility and power come from its template-based design, which allows it to work with various data types, including custom structs. This flexibility is particularly useful when working with complex data structures that require matrix-like operations. In this article, we’ll focus on mapping a custom struct with a double array to Eigen::Matrix, a fundamental concept in Eigen. By JerickPosted on July 20, 2024