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Monday, 2020 March 30, 10:35 — curve-fitting

Scribbles: The Ensmoothening, Part III

Many of the curves in this chart have some unsightly wiggles. That’s because, when a function of degree 2 or higher tries to approximate a piecewise constant, it tends to go back and forth across the target. So here instead I fitted each such function not to the piecewise constant directly but to the fit of the next lower degree.
( . . more . . )

Wednesday, 2020 March 11, 02:07 — merch

supply issues

I’ve had a number of mugs printed by Zazzle, and most of them came out gorgeous; but last summer I was peeved enough by a delivery cock-up to want to take my business elsewhere. Recently I got around to doing something about it, with even more disappointing results.

Threadless would not let me sign up. I can’t tell which of my address, handle and password offends it, let alone how.

Cafepress failed to upload my design.

Spreadshirt and CustomInk cannot do a wraparound design on a mug.

Who else is out there? Maybe I have cooled off enough to go back to Zazzle.

Monday, 2020 March 9, 20:18 — spam

pull the other one

This week I’ve had a flood of mail with titles like VIDEO OF YOU! and YOU GOT RECORDED!. A tweetmate asked me to save and share one, so here it is. Having deleted all the others without looking at more than the header, I don’t know how similar they are.

Hey! Check the sender of this email (From:), I sent this email from your account!

Your computer was infected with my malware, RAT (Remote Administration Tool), your browser wasn’t updated / patched, in such case it’s enough to just visit some website where my iframe is placed to get automatically infected, if you want to find out more – Google: “Drive-by exploit”.

My malware gave me full access and control over your computer, I got access to all your accounts (that’s how I sent this email) and it was possible to see everything on your screen, turn on your camera or microphone and you won’t even notice about it.

I was spying on you and I RECORDED YOU SATISFYING YOURSELF!

After that I removed my malware to not leave any traces.

I can send the video to all your contacts, friends, post it on social network, publish it on the whole web!

But, you can stop me!

Transfer exactly 1200$ with the current bitcoin (BTC) price to my bitcoin address.

You can easily buy bitcoin here: www.coingate.com , www.coinbase.com , or Google for other exchanger.
You can send the bitcoin directly to my address, or create your own wallet first here: www.login.blockchain.com/en/#/signup/ , then receive and send to mine.

My bitcoin address is: [redacted]

Copy and paste my address, it’s (cAsE-sEnSEtiVE)

I give you 3 days time to transfer the bitcoin.

As I got access to this email account, I will know if this email has already been read.
If you get this email multiple times, it’s to make sure you read it and after payment you can ignore it.
After receiving the payment, I will remove the video.

Next time update your browser before browsing the web!

Mail-Client-ID: 3063392989

Wednesday, 2020 February 12, 16:57 — prose

a sense of place?

I read Jack Vance’s memoir, of which many pages say “We went to Ireland / Tahiti / Kashmir . . . found a pleasant cottage and stayed there for a couple of months, cranking out stories.” It would be pleasant to know what was written where! Perhaps Jack himself did not remember. But it is impossible not to imagine that “The Moon Moth” was conceived on the houseboat in Kashmir.

Thursday, 2019 November 28, 19:51 — mathematics

it’s in the literature

On a truncated icosahedron / buckyball / Telstar-style soccer ball, consider two adjacent hexagons and the two pentagons that are adjacent to both. These four faces can be removed, rotated by a right angle, and reattached, causing only a small change to the overall shape. Most fullerenes have at least one such patch.

If I ever get around to making more printable models of fullerenes, I would omit those that can be changed, by the above twist, into one of higher symmetry. I have a pretty good idea of how I’d go about listing the fullerenes and finding their siblings; but I do not have a grip on distinguishing symmetry groups of the same order – e.g., that of the regular tetrahedron versus that of a hexagonal prism – and a subgroup of one may not be a subgroup of the other.

So I got out An Atlas of Fullerenes in the hope of understanding how they did it – and happened to open to a chapter I had not looked at before, which covers the Stone-Wales transformation (for so it is named) and lists, up to C50 (15 hexagons), which fullerenes change with which.

The 812 smallest fullerenes are thus cut to 72 in 47 families. The biggest of these families has six remaining members, four with C2v symmetry (one axis of twofold rotation, and a reflection plane containing that axis) and two with C3 symmetry (chiral with one threefold axis). Their symmetry numbers are 4 and 3 respectively, but as C3 is not a subgroup of C2v I keep them all.

Surprisingly the ten families of C50 include two with no nontrivial symmetry at all.

Wednesday, 2019 July 24, 09:24 — merch

I ain’t Zazzling any more

You probably haven’t noticed the absence of a link in the upper left, “buy 2D printed objects”, which went to my catalogue on Zazzle: shirts, mugs, posters. The number of sales I made through that was not zero, but it was far smaller than the number of things I bought myself!

Four years ago MC Escher’s heirs complained that my descriptions of two shirt designs included language like “The underlying geometry is closely related to that of Escher’s Circle Limit series,” so Zazzle hid them until I removed Escher’s name. No, wait, they didn’t do that, they irrevocably deleted the designs without warning, saying (until I raised a fuss) only that they violated an unspecified copyright.

Last week my step-family had a gathering at a resort in the Rockies, and I ordered a personalized mug for each of them. (Here is a hint at what they look like.) Zazzle was unhappy with the address I gave, but both Google and Apple Maps recognized it, so I said go ahead. When the package reached the town, it was bounced back for “insufficient address”. I then learned from the lodge’s owner (indirectly, through the family member who booked it) that USPS does not deliver to that street. (I wish I’d thought of General Delivery.) Fortunately this was well before we were due to get there. I suggested to Zazzle that, when the package came back, they try FedEx or UPS. They instead reprinted the order and sent it by Express Mail.

I go to the gathering, stay for a largely miserable week (insomnia), come home. Two days later, some iteration of the order is successfully delivered, I don’t know how. (The order’s tracking link shows only the first attempt.) So now the mugs are cluttering up a stranger’s kitchen; I hope the stranger finds them pretty. I point out to Zazzle that I told them twice that I wanted the package to arrive no later than Friday July 19. They tell me how to return it. I explain that everyone I know left that county on Saturday morning; I will not ask the lodge’s owner or the new occupants to do my errands.

We are really sorry about the various issues you have had, we would really appreciate the chance to try and make this right.

Please let us know if there is anything at all we can do for you. If you have any further questions or concerns please respond directly to this email and I would be happy to assist. Thank you for visiting Zazzle.

I don’t see how it can be made right. They can send mugs to the intended recipients separately, but I’d rather wait for the next gathering and present them all at once.

So. I haven’t tried Cafepress, and there must be other similar services. Have you experience with any of them?

Tuesday, 2019 June 4, 17:11 — blogdom, me!me!me!, neep-neep

all the world’s a wiki

I toy with the thought of converting this here website to MediaWiki (which my host supports), as I am more efficient at editing there than at writing raw HTML in vi.

The wiki’s first articles would be:

  • Two-dimensional design
    • Hyperbolic tilings
    • Arrangements of the color gamut in the plane
    • Curve-fitting
  • Three-dimensional design
    • Ray-tracing
    • Solid printing
  • Posthuman speculation
  • Political speculation
  • Linguistics
    • Diachronics
    • Writing
    • Conlang

I’d continue to report new thoughts here, and then integrate them into appropriate articles. I wonder whether MediaWiki and WordPress play well together. I’m not aware of any personal website that combines blog with wiki, but it seems unlikely that nobody does it.

And now I wonder whether a wiki on my home box would help me keep track of the little files I write as notes on this topic or that, and the PDFs that I download to read someday, and the

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