This is a GUI application (using Dear ImGui) for simulating the 2D Ising model (currently only for no applied magnetic field), using the Metropolis-Hastings algorithm.
It has two modes: a graphical mode with that offers real-time plotting using implot - this is mostly just for show/fun.
It also has a headless "experiment" mode you can use to collect statistics at different temperatures, to investigate e.g. heat capacity as a function of temperature.
In an attempt support as many platforms as possible, older OpenGL versions are supported, in addition to modern versions. To use modern OpenGL, set MODERN_GL_ENABLED = 1 in the makefile, or MODERN_GL_ENABLED = 0 to build for older OpenGL versions.
You will need the following packages - I assume you will download them with homebrew:
brew install sdl2 glfw glew glm
You will need the following packages: build-essential, libsdl2-dev, libglew-dev, and libglm-dev.
Windows is not officially supported yet, but it may be possible to get it to run.
Run the makefile with make from the project's root directory to build the application. If you get any errors you are likely missing some dependencies.
Run ./ising to start the GUI application. There are some GUI sliders you can use to change the lattice size and temperature.
To run it in the headless "experiment" mode, pass in the --experiment flag and specify a list of temperatures to run the simulation at, e.g. ./ising --experiment 2.1 2.2 2.27 2.3 2.4. Results will be written to experiment_summary.txt for analysis or plotting. The lattice size for the headless mode is 40 (I might make this configurable at some point). This wil genearte a csv file called experiment_summary.csv you can use for e.g. plotting.
Here is a screenshot of the application run on an M4 Macbook pro for 112 steps, at T=2, for a 500x500 lattice:
Here are plots of the net energy per spin, net magnetisation per spin, and heat capacity per spin, showing the expected behaviour (the plotting script is not included in this repo).
