MATLAB Program for Reading 2D Grid Data from Gambit

Gambit is a widely-used meshing software commonly employed for preprocessing in computational fluid dynamics and related fields. This article presents a MATLAB program for reading 2D mesh data generated by Gambit, with the methodology derived from the book "Nodal Discontinuous Galerkin Methods".

In scientific computing, Gambit mesh files typically contain crucial information such as node coordinates and element connectivity. The MATLAB program needs to parse this data for subsequent numerical computations. The reading process primarily involves the following implementation steps: first identifying the file format and data structure using file I/O operations, then extracting nodal position information through coordinate parsing algorithms, followed by establishing element connectivity relationships using matrix operations, and potentially handling additional information like boundary conditions through conditional logic.

This program is specifically designed for 2D meshes and can handle common 2D element types including triangles and quadrilaterals. The parsed data can be directly utilized for numerical implementation of nodal discontinuous Galerkin methods, which serve as powerful tools for solving partial differential equations. The code typically involves array manipulation for storing node coordinates and sparse matrices for efficient element connectivity representation.

It's important to note that different versions of Gambit may have subtle variations in file formats, requiring appropriate program adjustments in practical applications. Key functions like textscan or fscanf may need version-specific modifications. Through this approach, researchers can conveniently import Gambit-generated meshes into the MATLAB environment for subsequent numerical computations and visualization analysis using MATLAB's plotting capabilities.