I'll be posting the questions from AMS 2025 Daily Epsilon of Math Calendar daily from now on. I should have started earlier (doing it on Blue sky for some time). Hope it will be of interest

Here's the question for April 13th. For those unfamiliar with the calendar, the answer is always the day of the month. Looking for imaginative solutions is the aim.

Back on tech matters, lately I've been revisiting the Mahalanobis distance.

I had an intention ten years ago to seek an SQL method for deriving it, but it never became pressing enough, and the process using it - via an external call out - was only once once annually.

Returning to the same process ten years later, I've dug a little deeper and found that the callout had only been doing on each separate "variable" - and was thus equivalent to doing each as a simple "z-score".
#SQL #mathstodon

Search and @-resolution appear to be not working on #mathstodon. Am I the only one with this issue?

am i the only one who found search on #mathstodon extremely slow recently ?

# #Pachli 2.11.0 is released

## New features include

- Support translation throughout the app
- Experimental Markdown support
- Content filters default to all contexts

## Fixes include:

- Toot button accessibility
- Grammar fixes
- Report UI updates
- Content filter updates
- Fewer crashes

## Updated translations

- Finnish, Indonesian, Irish, Latvian, Norwegian Nynorsk, Polish, Slovak, Spanish

More details at https://pachli.app/pachli/2025/03/31/2.11.0-release.html.

Hey i poseted an image with question and my post is lost
Wtf #mathstodon ?
Nontheless that ll be my new dp now

The Fourier Transform is a mathematical operation that transforms a function of time (or space) into a function of frequency. It decomposes a complex signal into its constituent sinusoidal components, each with a specific frequency, amplitude, and phase. This is particularly useful in many fields, such as signal processing, physics, and engineering, because it allows for analysing the frequency characteristics of signals. The Fourier Transform provides a bridge between the time and frequency domains, enabling the analysis and manipulation of signals in more intuitive and computationally efficient ways. The result of applying a Fourier Transform is often represented as a spectrum, showing how much of each frequency is present in the original signal.

$$\boxed{{\displaystyle \boxed{{\displaystyle \hat{f}(\xi )={\int }_{-\mathrm{\infty }}^{\mathrm{\infty }}f(x)e^{-i2\pi \xi x}\mathrm{d}x,\mathrm{\forall }\xi \in \mathbb{R}.}}}}$$

Inverse Fourier Transform:
$$\boxed{{\displaystyle \boxed{{\displaystyle f(x)={\int }_{-\mathrm{\infty }}^{\mathrm{\infty }}\hat{f}(\xi )e^{i2\pi \xi x}\mathrm{d}\xi ,\mathrm{\forall }x\in \mathbb{R}.}}}}$$

The equation allows us to listen to mp3s today. Digital Music Couldn’t Exist Without the Fourier Transform: http://bit.ly/22kbNfi

Yes it is 3.14! Happy Pi Day!

Happy #PiDay to all my fellow earthlings! Don't forget to eat some pie today, or… well, let’s just say the circle of life might close in on you. And trust me, you don’t want to find out what happens when you divide by zero. So grab a slice — your survival might depend on it.

Reminder: you canhelp mathstodon.xyz to keep the lights on, it a fabulous instance: https://ko-fi.com/mathstodon - there's even a leaderbord, maybe YOU can kick me out of the top ten :)

Which is smaller?

https://www.nytimes.com/interactive/2025/03/01/business/trump-stock-market.html
#mathematics #math #mathstodon

I don’t know mates, should we shun discussing #American #politics on #MathsTodon? Besides, we won’t be losing much, because what we have now is not really politics, but a cult.

I'm looking for some pointers...

I have a vector in 3D space. I want to be able to manipulate its direction based on input pan and tilt angles... Importantly I'd like to be able to give these angles as absolute (i.e: from "up") or relative (i.e: from the current direction).

I have a working solution, but I suspect there's a more efficient way to do this. I had a stab with Quaternions, but I couldn't get the tilt to behave like it would on a gimble.

Any ideas?

https://jenniferleelawson.blogspot.com/2024/12/cantors-theorem-and-problem-of-infinity_38.html

#mathematics #math #mathstodon

https://www.defense.gov/News/Advisories/Advisory/Article/4076184/secretary-of-defense-pete-hegseth-to-travel-to-guantanamo-bay/
#mathematics #math #mathstodon

I feel as though the intersection of #mathstodon and #knitting will say, "yes of course", but it's still an enjoyable passage.

"knitting, at its core, is a method of transforming a one-dimensional strand of yarn into a structured, flexible two-dimensional sheet, which can then fold itself into complex three-dimensional shapes. The researchers realized that this transformation could be described mathematically using the same principles that govern how surfaces curve in space."

https://phys.org/news/2025-02-theoretical-physics.html

Open Letter to Cardiff University in Response to its Plans for the Future of Mathematics

We, the undersigned, call on Cardiff University to reverse its plans to impose compulsory redundancies on its staff in the School of Mathematics.

https://docs.google.com/document/d/e/2PACX-1vRD7gtY_80G6xIz3SPUwRNyiDSWkt_UcXDoEnmygM_c_tVsj7ZNIJ3CYM71IyLxOk5JQcQvtLvEhLro/pub