@christianp@mathstodon.xyz
@christianp@mathstodon.xyz avatar

christianp

@christianp@mathstodon.xyz

Mathematician, koala fan, mathstodon.xyz admin,
⅓ of https://aperiodical.com. He/him

This profile is from a federated server and may be incomplete. Browse more on the original instance.

christianp, to random
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with on a mac, after I press VO+Up to get out of the group I'm in, is there a way to quickly get back to the where I was inside that group? VO+Down takes me to the first item in the group.

JordiGH, to python
@JordiGH@mathstodon.xyz avatar

This is the first time I work for a company that I actively want to personally advertise for, but I really like what does. It's like a that's really a and lets you use as a computational language. And it's all open source!

Have some links!

https://getgrist.com

https://github.com/gristlabs/grist-core

And have some marketing materials!

The drafts were really good too:

https://docs.google.com/presentation/d/1kzmv4o2ZqRYeWPq_Y9LkS50whzcMrL_gn1zoV6EnJQA/

christianp,
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@JordiGH INTERESTING

christianp, to random
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Should I be concerned that my phone has stopped showing Microsoft access code requests?
I can't log in to Outlook or Teams on anything that isn't already logged in.

christianp,
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@dimpase unfortunately, Microsoft doesn't use the standard OTP - it's a challenge/response thing that needs their app

christianp, to random
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Isn't that ironic? The tickbox for "high contrast colors" is so faint I can hardly see it, or tell if it's ticked.

(and never mind that these things should all be on by default, possibly except for high contrast colours)

This is the EventsAir platform used for JISC

christianp, to random
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First shorts day of the year! Woop woop! ☀

christianp, to random
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Consider the factorisations of 30 into two proper factors. For each one, add the two factors:

30 = 2×15. 2 + 15 = 17
30 = 3×10. 3 + 10 = 13
30 = 5×6. 5 + 6 = 11

All of them give primes!

I thought this wasn't in the , but my code was wrong. It is, in fact, https://oeis.org/A140775

christianp,
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... BUT! The sequence I was originally thinking of is not. It is:

2,3,4,5,5,7,5,5,7,11,5,13,5,5,5,17,5,19,5, ...

This looks at what happens when you generalise the process above: pick a proper factorisation 𝑑₁×𝑑₂×…×𝑑ₖ of n, swap × to + to get 𝑑₁+𝑑₂+…+𝑑ₖ. Repeat the process on this sum, until you can't go any further (either a prime number or 4).

For starting number n, what's the lowest number you can end at?

christianp,
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The version where you just use the complete prime factorisation is in: https://oeis.org/A029908

christianp, to random
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Went into the department today, and was recognised in the corridor by a visiting seminar speaker.
I must have bumped into him before and forgotten. I'm not that recognisable, am I?

christianp, to random
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am I going mad? Compiling beamer slides on windows, it seems to be case-sensitive for colour names: "Blue" causes an error, but "blue" doesn't. Mac and Linux are fine with either.
How could this be???

christianp,
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@samcarter we were using xcolor=svgnames. I wondered if there were separate definitions of blue and Blue. I wonder why pdflatex on linux is happy to ignore it, but on WSL it isn't?

j2kun, to random
@j2kun@mathstodon.xyz avatar

Now that I have a static site with hugo, I wonder if people would like reading shorter-form thoughts, and they can be cordoned off into their own part of the site and/or their own RSS feed.

I feel like there are a lot of small mathematical tidbits I learn about that I don't have the time/energy to put into a proper article, but are still worth spreading.

christianp,
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@j2kun you could make a request to the mastodon API as part of your deploy step?

wnd, to uk
@wnd@fosstodon.org avatar

Today I have been dusting off some old code looking at the perennial question of "where is the centre of country x" for a value of x is the UK.

I here are two methods of identifying the centre point, one based on a geographic bounding box centroid for the UK, and a population centroid calculated by slicing the UK into 100m horizontal and vertical rectangles and working out the cumulative centre point using @WorldPopProject data in an EPSG:3034 projection

Detailed map using OpenStreetmap data projected on EPSG:3034 the centre point for the UK at a point in a field in the Southern borders of Scotland and England
Map using OpenStreetmap data projected on EPSG:3034 the population centre point for the UK corresponding to a field between somewhere between Montilo Farm and Pailton near Rugby
Detailed map using OpenStreetmap data projected on EPSG:3034 the population centre point for the UK corresponding to a field between somewhere between Montilo Farm and Pailton near Rugby

christianp,
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@wnd wow! I knew that it's not as built up here, but I was surprised that Tyneside doesn't even make a faint horizontal line

lowrankjack, to random
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Really sick of all and that insert a gray "for review only" (or similar sentence) as a watermark in the background of each papers to be reviewed. This is super annoying as it makes any selection of text in the pdf impossible (for most places). I'm usually often selecting text, for instance to cite authors own words in my review letter, or point them a typo, or a conceptual issue. What does this watermark really prevent? If someone with bad intention really wants to use the reviewed work, they'll find a way and this pseudo watermark won't prevent anything. If a mention "for review only" is needed, why not placing it only on the top or the bottom of the document so that it doesn't corrupt any text selection?

christianp,
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@lowrankjack for natural sciences, could it be to prevent the spread of misinformation? If an unmarked PDF of an unpublished paper spreads, it'd look to a layman like something that's been published, with the weight of authority of the journal.
I know that in covid people had trouble differentiating spurious preprints from proper science.

j_bertolotti, to random
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Dear wannabe barista: there is a difference between "warm milk" and "scalding milk". The difference is especially important when you are preparing it for a kid.

christianp,
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@j_bertolotti I have yet to ask for warm milk for my kids and get anything close to cool enough to drink. It must be a machine problem or a policy problem. I can't believe everyone is incompetent

mathyawp, to random
@mathyawp@mathstodon.xyz avatar

N3.5yo is now into the idea of opposites: short/tall, up/down, etc. So I asked for things he had not practiced. He thought about each for a few seconds.

The opposite of spoon? “Fork.”
Sick? “Ambulance”.
Kleenex? “Sneeze.”
Lego? “Taking away legos!”

I like these answers! ❤️

christianp,
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@mathyawp my son, also 3.5, has a congenital sign error. He'll say things like "I'm too big for these shoes" when he means "these shoes are too big for me".
He's perfectly consistent, just... opposite

brad, to random
@brad@bne.social avatar

The manufactured urgency in kids shows stresses me out. You scheduled a gig but only form the band and write any material the day of? You scheduled a museum opening without an exhibit and left it to the day of to create one? Why? What on earth has lead to this scenario?

christianp,
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@brad I'm still prefixing everything with "go go gadget"

astrolabe_cat, to random
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My research group has a maths education PhD position available. (Not maths, please note, but maths education). The position is within FERMAT, the mathematics education research group at the University of Twente.

https://utwentecareers.nl/en/vacancies/1747/phd-position-on-automated-and-alternate-assessment-in-undergraduate-mathematics/

christianp,
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@astrolabe_cat

  1. I'm very interested in your research group! I'm happy to talk to you about @numbas if you'd like.
  2. that salary for a PhD student makes me weep. It beats many of our post-doctorate positions!
christianp, to random
@christianp@mathstodon.xyz avatar

Trying to buy some trousers.
This is hard because I have a 36" inside leg.
On one site, the options are "short", "regular", and "long". I wanted to know how long "long" wast. It has an expert system that said it would recommend the right size for me.
I go through the whole process, giving it more dimensions of data than the two they offer their trousers in (but would be useful for their marketing...), and it said my perfect fit would be "36 regular".
Start to wonder: am I being precious? Are my legs not in fact that long?
Read through all the small print, and finally discovered that "long" is a 33" inside leg. So not, in fact, long.

So many shops do this: they say they do big sizes, but in fact "big" is just a little bit more than average. Like shoe shops that stop at size 12 (all of them).

christianp,
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@astronomerritt both Fat Face and M&S only have lengths 29", 31" and 33".
Is men's inside leg measured differently to women's?

christianp,
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(PS if you also have long British legs, Brook Taverner go up to 37" and the fit is very consistent. They're unnervingly cheap, unlike specialist big and tall shops. But the pockets are still small-person-sized so I always look around in vain for something else before buying from them)

christianp,
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@astronomerritt cripes!

christianp,
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@astronomerritt I'm 6'5", so... how high up are your trousers going??

christianp,
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@mathmats 2tall is so expensive!

christianp, to random
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'Developers stop saying "modern" to differentiate from the thing you were doing six months ago' challenge

christianp,
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: this again

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