jatlab/jatlab.github.io

JATLAB turns any modern web browser into a scientific calculator similar to MATLAB, a widely used engineering and math software package. The author explains they used MATLAB for years as a quick calculator, but found newer versions increasingly bloated, slow to load, and heavy on memory and CPU, while its license became more expensive and less available. JATLAB is an attempt to recreate the most commonly used parts of that experience for free, directly in the browser. To use it, you open the project's website in a browser like Chrome or Edge and press F12 to open the browser's built in developer console. From there, common math functions such as sin, cos, exp, log, and square root can be typed without needing to prefix them, and most of these also work directly on one or two dimensional arrays, not just single numbers. It also reimplements many familiar MATLAB style features: plotting graphs and simple 3D style visualizations like heatmaps and contour plots, reading and writing CSV files, running FFT (a common signal processing calculation), common statistics like mean and root mean square, complex number handling, creating arrays and matrices of zeros, ones, or random numbers, and simulating equations over time. Because JavaScript, the language the browser understands, does not support some of MATLAB's shortcuts, such as adding two arrays directly with a plus sign, JATLAB provides its own functions like add, scale, and dot for those operations, and represents matrices as arrays of arrays rather than a dedicated matrix type. The README includes several worked examples, including basic plotting, simulating a physics equation over time and visualizing it as a heatmap, saving and reloading data as CSV files, and analyzing a signal with FFT. The README frames MATLAB as a huge piece of software and says the author hopes others will contribute over time to expand what JATLAB can do. It notes one limitation up front: for security reasons, JavaScript running in the browser cannot automatically read a file it just saved, so users need to manually pick the CSV file again through their browser's file chooser when loading data back in.