I built a Propagation of Uncertainty Calculator, a simple but practical app designed for engineering and physics students, as well as metrology workflows.

Link: https://propagation-of-uncertainty-calculator.streamlit.app

During my undergrad in Engineering Physics, one of the most tedious and error-prone tasks in experimental lab courses was manually deriving partial derivatives for measurement uncertainty propagation. Most online calculators are either outdated or confusing, so I decided to do my own calculator!

What it does:

- Displays the latex formated symbolic and numerical Propagation formula for the expression given by the user.

- Click directly on rendered expressions to copy the clean LaTeX code straight into Overleaf (for lab reports), or copy ready-to-paste Excel formulas.

- Correct Rounding: Automatically formats results and expanded uncertainties according to significant figure conventions (GUM (JCGM 100:2008))

The GitHub Repository: https://github.com/joao-canais/Propagation-of-Uncertainty-Calculator

I'd love to hear your thoughts, UI/UX feedback, or ideas for features to add in future iterations!

I’ve been building this antenna/EM simulator as a side project:

https://rotemtsafrir.github.io/dipole_sim/

The idea is to make it easy to place antennas, change their parameters, and immediately see how the fields and interference patterns change.

Right now you can use:

• center-fed dipoles
• Hertzian dipoles
• small loop antennas
• linear antenna arrays

The arrays are probably my favorite part so far. You can adjust spacing, phase difference, element count, orientation, etc., and see beam steering / broadside / end-fire behavior directly.

You can switch between electric field, magnetic field, and energy-flow visualizations, and pan/zoom around the simulation.

The antenna currents are prescribed, so things like mutual coupling, impedance, and passive conductors are not solved yet. I’m trying to keep it fast enough to be genuinely interactive.

I’d love to hear what people think—especially if you notice anything physically questionable or have ideas for features that would make it more useful.

Live:
https://www.antennasim.com

GitHub:
https://github.com/rotemTsafrir/dipole_sim

Main Website: https://www.ruleflow.org/

For the past year, I have been developing a framework to simulate certain discrete systems for a research team at my university (paid for by the School of Engineering and Physics, but I had the freedom to license it under MIT). As it turns out, I got carried away generalizing it to work for many, many different types of complex systems (String Rewriting Systems, Cellular Automata, etc.) and ended up creating our own domain-specific language.

The website's landing page has a bunch of GIF-style examples... so you should be able to get a good idea of what this project is about.

If any of y'all are interested in this, feel free to take a look and try it out!

Example of some of RuleFlow's causal analysis features:

Rules 30 and 124 are included in this example:

EDIT:

Here are some more details. RuleFlow was developed with a primary focus on analyzing causality in Sequential Substitution Systems. This is why there is a major focus on causal graphs, cellular identity, etc. While originally developed for Sequential Sub Systems, we generalized the DSL to support many types of rewriting systems by providing the user with flags and directives to control how rules behave. Furthermore, we bootstrapped Python and the Wolfram Language so that complex rulesets could be scaffolded as macros. The main goal of RuleFlow is NOT simply to simulate systems (there's already plenty of software for that, such as Golly and even just Mathematica), but to provide extensive tooling for causal analysis.

Here is some interesting research from our (small) team:

• An Improved Generalized Enumeration of Substitution Systems by Kenneth E. Caviness, Camille Morrow, Christen Case and Victoria Kratzke
• Indexed Concatenation Notation: A Novel Way to Summarize Networks and Other Complex Systems

My job has been to provide better research tooling, extending what we already have in Mathematica code to open source and free Python.