Odds and Ends: Feb 24, 2013

Sage 5.7 was released recently. The changelog is here.

I've added 2 links to the sidebar: ChessBomb is a great website for following top chess events. They provide real time chess analysis with a computer engine. It's all free, but if you're willing to register then you'll get even more features. With respect to LaTeX, I've finally gotten around to adding a link to TUG (Tex Users Group).

I've added information to the LaTeX page: a link to free PDFs on PSTricks and on the Sage Interact Essentials page there is now a link to the colors that can be referenced by SAGE.

Some websites that are worth a look: Online Schach Analyse for online analysis of chess positions. Several engines are available. Perhaps a convenient tool if you are on the road with no access to a chess engine? Math-Fail.com has a Happy Face Cheat Sheet you might find amusing.

Sage Interact: Recursive Square

In an earlier post, I mentioned the TeXample.net. It's a great website to look around and see the amazing power of creating graphics with LaTeX. This week I spent some time working on the Rotated Square example using Sage. Although it's nice to see LaTeX create interesting graphics, sometimes it doesn't make a whole lot of sense to me. The rotated square is one such example. By creating a Sage Interact manipulative I can get quick control over a lot of the important factors in creating the picture, such as how much the square has rotate, the number of iterations, and the coloring rule. That gives you the power to quickly experiment until you create the example that looks just right. I put together the Sage code to create the shape, which I've been referring to as recursive square. Here is the code running in the Sage Cell Server.

RecSquareYou can find the code posted on the Python/Sage page. If you look at the code in the picture, I've commented out a line which would draw the lines of the square. Then removing the code generating the colored triangles would give you a simple picture where you can focus just on the squares and not the colors. Sage Interact gives you the chance to play around with your own coloring rules, starting colors, iterations and so forth quickly and easily. Sage even gives you the ability to output the graphics to eps files, too. Sometimes Sage is just better than LaTeX.

LaTeX: Generic Test Template

I've added a generic test template to the Handouts page. Here's a screenshot of the first page; click on it to enlarge.

GenericTestTemplate1Notice in the code that the code has \documentclass{exam}, rather than article. You can download a PDF with more information on the exam class here;  using it makes test creation a little bit easier. I like the answer lines which save you from having to hunt for that final answer.

I've used the fix-cm package to make the fonts larger: students complained that the traditional default size fonts were too small. There's even an included a section for the answers which you might not appreciate for now but it will be very useful, however, when  the sagetex package is added. I thought a generic template (without sagetex) would be useful for those who didn't need the power of Sage in their documents.

The template has 3 inputs: the course, teacher name, and title of the quiz/test. You can see that information in the red box below:


Modify the information to include your math course, the title of your quiz/test and your name; it will appear at the top of every page other than the first. I debated about including the course information on the first page but found in my particular case that having the class period was more important.

Chess Basics: Smothered Mate

In chess, a "smothered mate" is a checkmate in which the knight gives checkmate to the enemy king and the king, unable to move because all the squares around it are occupied by other pieces, is “smothered”. Once you're aware of the basic idea you'll see it in games or analysis variations for games.

Smothered mate is an essential theme every beginner needs to know; you can find a post on it on the Chess page.