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Tag: games

thanks for linking

I’ve re-installed the Google analytics plugin on december 22nd, so it is harvesting data for three weeks only. Still, it is an interesting tool to gain insight in the social networking aspect of math-blogging, something I’m still very bad at…

Below the list of all blogs referring at least 10 times over this last three weeks. In brackets are the number of referrals and included are the average time Avg. they spend on this site, as well as the bounce back rate BB. It gives me the opportunity to link back to some of their posts, as a small token of gratitude. I may repeat this in the future, so please keep on linking…

Not Even Wrong (69) : Avg (1.05 min) BB (52.94%)

The most recent post of Peter is an update on the plagiarism scandal on the arXiv.

The n-category cafe (63) : Avg (2.13 min) BB (50%)

The one series I followed at the cafe lately was the Geometric Representation Theory course run by John Baez and James Dolan. They provide downloadable movies as well as notes.

Richard Borcherd’s blog (47) : Avg (1.53 min) BB (53.19%)

It is great to see that Borcherds has taken up blogging again, with a post on the uselessness of set theory.

The Arcadian functor (32) : Avg (3.45 min) BB (34.38 %)

It is clear from the low bounce-back rate and the high average time spend on this site, that Kea’s readers and mine have common interests. Often I feel that Kea and I are talking about the same topics, but that our language is so different, that it is difficult for me to spot the precise connection. I definitely should start (for myself) a translation-project of her M-theory posts.

RupertGee’s iBlog (23) : Avg (6.48 min) BB (34.7 %)

Surprisingly, and contrasting to my previous rant iTouch-people (or at least those coming here from Rupert Gee’s blog) sure take time to read the posts and look for more.

Ars Mathematica (22) : Avg (0:01 min) BB (77,2 %)

Well, the average time and bounce back rate say it all : people coming here from Ars Mathematica are not interested in longer posts…

iTouch Fans Forum (14) : Avg (2:07 min) BB (42.86 %)

Again, better statistics than I would have expected.

Vivatsgasse 7 (13) : Avg (1:51 min) BB (38.46 %)

I hope these guys haven’t completely given up on blogging as it is one of my favourites.

Sixth form mathematics (12) : Avg (1:40 min) BB (25 %)

My few old posts on LaTeXrender still draw referrals…

Strategic Boards (12) : Avg (0:01 min) BB (91.67 %)

People in strategic board games are not really in my game-posts it seems…

The Everything Seminar (11) : Avg (2:04 min) BB (72.73 %)

Greg Muller has been posting a couple of nice posts on chord diagrams, starting here.

Noncommutative Geometry (11) : Avg (3:36 min) BB (27.27 %)

Well, we are interested in the same thing viewed from different angles, so good average times and a low bounce back rate. Maybe, I should make another attempt to have cross-interaction between the two blogs.

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IF on iTouch

Interactive Fiction (IF) describes software simulating environments in which players use text commands to control characters and influence the environment. Works in this form can be understood as literary narratives and as computer games. In common usage, the word refers to text adventures, a type of adventure game with text-based input and output. As the text-input is minimal (most commands have 1 letter abbreviations), text-games are ideal to be played on the iTouch.

Luckily, one of the most popular IF-interfaces, Frotz, is ported to the iPhone/iTouch as iPhoneFrotz. The easiest way to install is just to install the Frotz package using Installer.app. Just install the “Community Sources” package, which contains the installer repository (which hosts Frotz as well as other games and utilities), then look for Frotz under the Games section.

A collection of 3 Zork-derivatives (although not the original Infocom titles) is also available in the “Zork Z-Code” package.

There are hundreds of Z-Code games, and no one is likely to package your favorites for easy installation by Installer.app. But the games can be downloaded and copied to the phone without too much trouble.

Z-Code games are typically have filenames ending in .z3, .z4, .z5 or .z8 (depending on version), although game files from original Infocom media end in .dat. These should be copied to the phone’s Frotz/Games folder (under /var/root/Media).

Here is a link to the The IF archive and an archive of all Z-games. Another interesting site is the Inform 7-site

Inform is a design system for interactive fiction, a new medium for writers which began with adventure games in the late 1970s and is now used for everything from literary narrative fiction through to plotless conceptual art, and plenty more adventure games too. Since its introduction in 1993, Inform has become a standard tool.
Three years in the making, Inform 7 is a radical reinvention of the way interactive fiction is designed, guided both by contemporary work in semantics and by the practical experience of some of the world’s best-known writers of IF.

In place of traditional computer programming, the design is built by writing natural English-language sentences:
– Martha is a woman in the Vineyard.
– The cask is either customs sealed, liable to tax or stolen goods.
– The prevailing wind is a direction that varies.
– The Old Ice House overlooks the Garden.
– A container is bursting if the total weight of things in it is greater than its breaking strain.
Inform’s power lie in its ability to describe: to lay down general rules about “closed doors”, or “bursting containers”, or “unmarried men liked by Martha”. At its best, expressing IF in natural language results in source text which is not only quick to write, but very often works first time, and is exceptionally readable.

Inform 7 is available for most platforms and can be downloaded here.

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daddy wasn’t impressed

A first year-first semester course on group theory has its hilarious moments. Whereas they can relate the two other pure math courses (linear algebra and analysis) _somewhat_ to what they’ve learned before, with group theory they appear to enter an entirely new and strange world. So, it is best to give them concrete examples : symmetry groups of regular polygons and Platonic solids, the symmetric group etc. One of the lesser traditional examples I like to give is Nim addition and its relation to combinatorial games.

For their first test they had (among other things) to find a winning move for the position below in the Lenstra’s turtle turning game. At each move a player must put one turtle on its back and may also turn over any single turtle to the left of it. This second turtle, unlike the first, may be turned either onto its feet or onto its back. The player wins who turns the last turtle upside-down.

So, all they needed to see was that one turtle on its feet at place n is equivalent to a Nim-heap of height n and use the fact that all elements have order two to show that any zero-move in the sum game can indeed be played by using the second-turtle alternative. (( for the curious : the answer is turning both 9 and 4 on their back ))

A week later, one of the girls asked at the start of the lecture :

Are there real-life applications of group-theory? I mean, my father asked me what I was learning at school and I told him we were playing games turning turtles. I have to say that he was not impressed at all!.

She may have had an hidden agenda to slow me down because I spend an hour talking about a lot of things ranging from codes to cryptography and from representations to elementary particles…

For test three (on group-actions) I asked them to prove (among other things) Wilson’s theorem that is

$~(p-1)! \equiv -1~\text{mod}~p $

for any prime number $p $. The hint being : take the trivial action of $S_p $ on a one-element set and use the orbit theorem. (they know the number of elements in an $S_n $-conjugacy class)

Fingers crossed, hopefully daddy approved…

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