(1/2) Hands-On Mathematical Optimization with Python 🚀
The Hands-On Mathematical Optimization with Python book by Krzysztof Postek, Alessandro Zocca, Joaquim Gromicho, and Jeffrey Kantor provides the foundation for mathematical optimization. As the name implies, the book is hands-on with Python examples, mainly using Pyomo.
Im currently working on trajectory systems and forgot what tan() does and I kinda am embarrassed about that. Also I'm awful at trigonometry apparently. Haven't thought about it in a couple decades!
I just realized that all perfect squares mod 9 can only be 0, 1, 4, 7, but I can't find an easier proof than by exhaustion (square all numbers 0 to 8, mod 9). Is there a more elegant proof of this?
mod 11 has a wider choice (0, 1, 3, 4, 5, 9), but I wonder how good of a “perfect square detector” they can be together. Of course if either proof (by 9s and by 11s) fails, it's not a perfect square, but how many “not perfect square” are perfect squares both mod 9 and mod 11?
I have a question about the aperiodic spectre tile (or the hat/turtle).
I know that the proof of aperiodicity works by showing that the tiles must fit together in a hierarchical structure that eventually repeats itself at a larger scale. But the larger units aren't literally scaled copies of the spectre. I also know that there is some freedom as to how you draw the edges of the spectre.
Is there a way you can draw the edges that allows you to literally use spectres to cover a larger copy of themselves? If so, is this way of doing it unique?
I said this to a room full of people years ago and it turned out to be controversial, so what the heck I'll post it here:
Science results and math theorems should not be named after people, and we should undertake to rename any that currently are. We should prioritize renaming results or theorems named after white men and other privileged categories of people, with special attention to cases where a privileged person accepted or was assigned credit for work a less-privileged person did.
"Mathematics must subdue the flights of our reason; they are the staff of the blind; no one can take a step without them; and to them and experience is due all that is certain in physics." – Voltaire (1694-1778) #quote#mathematics#math#maths
[ \sum_{n=0}^{\infty} {\frac{n^4}{n!}}=15e ]
This is strange enough to provoke wonder, but simple enough to serve as an entry-point to an interesting generalization.
#kdtree and ball trees seem cool, but require full knowledge of the thing I'm searching for. What if it's 7 dimensional and I only know 4 of the values?
I feel like a "parallel kd tree" with a separate binary index on each dimension would work better here.
Reduce depth. Allow unspecified values. It'd also be a snap to create and search each dim in parallel.
One of the current book bundles at HumbleBundle contains 3 books by John Horvath and Rich Cameron featuring #OpenSCAD for visualization and examples (among 15 in total with various topics on electronics and robots).
True story. When I started working on my song, The New Rage, I knew it was for #fedivision so it's working title was "betrayed by math" because @futzle won last year with a very clever math adjacent song. Only thing that remains are the lines "...when it adds up to nothing. Add it to nothing" #fedivision24#math
I bet that a lot of people in the Fediverse already know this very pretty pencil-based 3D art. But in case you haven’t, be prepared to marvel.
This sculpture is known as the hexastix and a variant series created by artist George Hart is titled 72 Pencils.
If you can get 72 unsharpened hexagonal pencils, and some flat rubber bands, you can attempt to create this. Search for a video by @standupmaths for a pseudo-tutorial.
"Numbers are free creations of the human mind, they serve as a means of apprehending more easily and more sharply the diversity of things." – Richard Dedekind (1831-1916) #quote#mathematics#math#maths#numbers
Ok, this one is for the discrete #math gurus out there.
Let N = CRC32(X)
Given N, is it possible to efficiently calculate CRC32(concat(X, Y)) where Y is a known sized, but very long, sequence of 0xFF bytes?
Obviously you can just seed the CRC with N and iterate, feeding 0xFF in each cycle, but is there any kind of shortcut you can take if you know the input is always a 1 bit?
Brian Conrad, the Stanford mathematician who has written extensively about the problems with the proposed California Mathematics Framework (CMF), is now the subject of a formal complaint filed with Stanford University by the President of the central section of the California Math Council accusing him of "reckless disregard for academic integrity".