ces page 16 - Dave's Blog

The Wii Fit's Mind Games

Sarah received her Wii Fit a few weeks ago. The Wii Fit is a game for the Wii and a balance board accessory that can tell how you're standing on it: leaning forward, standing on one foot, leaning backward and mostly on your left foot, etc. The game puts you through various exercises grouped into the categories of aerobic, balance, strength, and yoga. It also lets you set goals and keeps track of how well you do, how long you play, and a graph of your weight.

The portion I didn't expect were the mind games. Sarah turned it on after not using it for a day and it said something to the effect of 'Oh, didn't have time to exercise yesterday? Huh. Interesting....' I'm paraphrasing of course but the Wii Fit was definitely trying to lay down some guilt. In another instance when starting up the Wii Fit Sarah was asked 'Did you know that Dave has been using Wii Fit?' She selected yes and it then asked her how she thought I was progressing giving her four options. She selected the worst one, that I was getting worse (jokingly I hope) and it told her to tell me that, but not to use those words. In conversation Sarah should mention to me that I've been "living large". Now I'm not paraphrasing. It reminded me a bit of this xkcd comic 'Zealous Autoconfig'. Hopefully this is the extent of the manipulation and mind games that the Wii Fit will perform.

GPS Stolen

My GPS was stolen last night or this morning and I'm missing it already. For instance when I drove to Novus glass repair to get my front passenger window replaced I drove down the wrong road for a while.

When I got out of my apartment this morning there was a police car sitting in my parking lot and the officer asked me: "David? ... What'd you leave in your car?". My face must have changed a lot when I had the following sequence of realizations: (a) a police officer is asking for me by name, (b) I'm not in trouble, (c) my car must have been burgled, and (d) my GPS must be stolen.

The officer was waiting outside my complex because someone had reported my car's broken window to the police in the morning. The officer was very courteous and upon taking my date of birth noted that we were born on exactly the same day. The window's safety glass was shattered and lying in tons of tiny pieces all over the passenger seat, my glove box was open and the middle armrest where I keep my CDs was open. Nothing appears to be missing other than the GPS, the GPS power cable, and the GPS dash mount. Adding insult to theft, the their scattered my CDs throughout my car and didn't take any of them, insulting my taste in music.

My car's window should be repaired now and hopefully the rain that came in through the broken window until I covered it with plastic bags (classy!) didn't do any permanent damage.

Generating N-D Tetris Pieces

When I woke up this morning for some reason I was thinking about Polytope Tetris, my N-D Tetris game, and specifically generating Tetris pieces in various number of dimensions. When I first wrote PTT I thought that as the number of dimensions increased you could end up with an infinite number of non-equivalent crazy Tetris pieces. However this morning I realized that because you only get four blocks per piece there are only a possible three joints in a single Tetris piece which means that you only need three dimensions to represent all possible distinct N-D Tetris pieces.

Below is the table of the various possible pieces per number of dimensions and sorted by the number of joints in the piece. Notice that the 'J' and 'L' become equivalent in 3D because you can rotate the 'J' through the third dimension to make it an 'L'. The same happens for 'S' and 'Z' in 3D, and 'S+' and 'Z+' in 4D.

Joints	Name	1D	2D	3D	+
1	I
2	J
	L
3	O
	T
	S
	Z
	T+
	S+
	Z+
	Total	1	7	8	7

As a consequence of not realizing there's a finite and small number of N-D Tetris pieces, I wrote code that would randomly generate pieces for a specified number of dimensions by wandering through Tetris space. This consists of first marking the current spot, then randomly picking a direction (a dimension and either forward or backward), going in that direction until hitting a previously unvisited spot and repeating until four spots are marked, forming a Tetris piece. However this morning I realized that continuing in the same direction until reaching am unvisited spot means I can't generate the 'T+' piece. I think the better way to go is keep the list of all possible pieces, pick one randomly, and rotate it randomly through the available dimensions. Doing this will also allow me to give distinct pieces their own specific color (like the classic Tetris games do) rather than picking the color randomly like I do now.

Leaking Information Through Delicious

While re-reading Cryptonomicon I thought about what kind of information I'm leaking by posting links on Delicious. At work I don't post any Intranet websites for fear of revealing anything but I wondered if not posting would reveal anything. For instance, if I'm particularly busy at work might I post less indicating something about the state of the things I work on? I got an archive of my Delicious posts via the Delicious API and then ran it through a tool I made to create a couple of tables which I've graphed on Many Eyes

Attended Savor Seattle

This past Saturday Sarah and I took the Savor Seattle Tour of various food shops in Pikes Place. Sarah had suggested it at one point and when Jesse and Nicole brought it up again when they came up to Seattle we decided to go. Surprisingly our tour group consisted of mostly locals. Except for the fish market I hadn't been to see any of the places on the tour. I particularly enjoyed the chocolate cherries and the tea. Our tour guide Tim was funny and overall I enjoyed the tour and would recommend it. I've made a map of our tour including what free trials we got at each location. Yum!

Cirque du Soleil in Marymoor Park

Sarah and I went to Cirque du Soleil's Corteo this past Wednesday. Its in Marymoor Park quite near the main Microsoft campus. They setup large circus tents in the park including a gift shop, overpriced concession stands, and long lined porta-potties. Despite all this the show was very entertaining and quite enjoyable. The show is like a circus directed by Terry Gilliam or Tim Schafer and otherwise I'm not sure how to describe it, but I do recommend it.

Saul and Ciera's Wedding

Last weekend while Sarah was up in Canada for a spa weekend with her sister and her sister's other bridesmaids, I went to Saul and Ciera's wedding in Three Rivers, California near Sequoia National Park. I flew into Fresno picked up a rental car and my GPS device navigated me to a restaurant with the wedding location no where in sight. "No problem," I thought, "I'll just call someone with an Internet connection and..." I had no cell reception. What did people do before GPS, Internet, and cell phones?

A waitress in the restaurant pointed me down the road a bit to the wedding location which was outside overlooking a river. Their wedding cake was made up like a mountain with two backpacks at the top and rope hanging down. Ciera's father married them and the ceremony was lovely. The music after included Code Monkey to which all the nerds were forced to get up and awkwardly dance.

Besides getting to see Ciera and Saul who I hadn't seen in quite a while, I got to see Daniil and Val, Vlad, and Nathaniel. Since last I saw Daniil and Val they had a child, Katie who is very cute and in whom I can see a lot of family resemblance. The always hilarious Vlad, Daniil's brother, was there as well with his wife who I got to meet. Nathaniel, my manager from Vizolutions was there and I don't know if I've seen him since I moved to Washington. It was fun to see him and meet his girlfriend who was kind enough to donate her extra male to male mini-phono cord so I could listen to my Zune in the rental car stereo on the drive back.

URI Fragment Info Roundup

Information about URI Fragments, the portion of URIs that follow the '#' at the end and that are used to navigate within a document, is scattered throughout various documents which I usually have to hunt down. Instead I'll link to them all here.

Definitions. Fragments are defined in the URI RFC which states that they're used to identify a secondary resource that is related to the primary resource identified by the URI as a subset of the primary, a view of the primary, or some other resource described by the primary. The interpretation of a fragment is based on the mime type of the primary resource. Tim Berners-Lee notes that determining fragment meaning from mime type is a problem because a single URI may contain a single fragment, however over HTTP a single URI can result in the same logical resource represented in different mime types. So there's one fragment but multiple mime types and so multiple interpretations of the one fragment. The URI RFC says that if an author has a single resource available in multiple mime types then the author must ensure that the various representations of a single resource must all resolve fragments to the same logical secondary resource. Depending on which mime types you're dealing with this is either not easy or not possible.

HTTP. In HTTP when URIs are used, the fragment is not included. The General Syntax section of the HTTP standard says it uses the definitions of 'URI-reference' (which includes the fragment), 'absoluteURI', and 'relativeURI' (which don't include the fragment) from the URI RFC. However, the 'URI-reference' term doesn't actually appear in the BNF for the protocol. Accordingly the headers like 'Request-URI', 'Content-Location', 'Location', and 'Referer' which include URIs are defined with 'absoluteURI' or 'relativeURI' and don't include the fragment. This is in keeping with the original fragment definition which says that the fragment is used as a view of the original resource and consequently only needed for resolution on the client. Additionally, the URI RFC explicitly notes that not including the fragment is a privacy feature such that page authors won't be able to stop clients from viewing whatever fragments the client chooses. This seems like an odd claim given that if the author wanted to selectively restrict access to portions of documents there are other options for them like breaking out the parts of a single resource to which the author wishes to restrict access into separate resources.

HTML. In HTML, the HTML mime type RFC defines HTML's fragment use which consists of fragments referring to elements with a corresponding 'id' attribute or one of a particular set of elements with a corresponding 'name' attribute. The HTML spec discusses fragment use additionally noting that the names and ids must be unique in the document and that they must consist of only US-ASCII characters. The ID and NAME attributes are further restricted in section 6 to only consist of alphanumerics, the hyphen, period, colon, and underscore. This is a subset of the characters allowed in the URI fragment so no encoding is discussed since technically its not needed. However, practically speaking, browsers like FireFox and Internet Explorer allow for names and ids containing characters outside of the defined set including characters that must be percent-encoded to appear in a URI fragment. The interpretation of percent-encoded characters in fragments for HTML documents is not consistent across browsers (or in some cases within the same browser) especially for the percent-encoded percent.

Text. Text/plain recently got a fragment definition that allows fragments to refer to particular lines or characters within a text document. The scheme no longer includes regular expressions, which disappointed me at first, but in retrospect is probably good idea for increasing the adoption of this fragment scheme and for avoiding the potential for ubiquitous DoS via regex. One of the authors also notes this on his blog. I look forward to the day when this scheme is widely implemented.

XML. XML has the XPointer framework to define its fragment structure as noted by the XML mime type definition. XPointer consists of a general scheme that contains subschemes that identify a subset of an XML document. Its too bad such a thing wasn't adopted for URI fragments in general to solve the problem of a single resource with multiple mime type representations. I wrote more about XPointer when I worked on hacking XPointer into IE.

SVG and MPEG. Through the Media Fragments Working Group I found a couple more fragment scheme definitions. SVG's fragment scheme is defined in the SVG documentation and looks similar to XML's. MPEG has one defined but I could only find it as an ISO document "Text of ISO/IEC FCD 21000-17 MPEG-12 FID" and not as an RFC which is a little disturbing.

AJAX. AJAX websites have used fragments as an escape hatch for two issues that I've seen. The first is getting a unique URL for versions of a page that are produced on the client by script. The fragment may be changed by script without forcing the page to reload. This goes outside the rules of the standards by using HTML fragments in a fashion not called out by the HTML spec. but it does seem to be inline with the spirit of the fragment in that it is a subview of the original resource and interpretted client side. The other hack-ier use of the fragment in AJAX is for cross domain communication. The basic idea is that different frames or windows may not communicate in normal fashions if they have different domains but they can view each other's URLs and accordingly can change their own fragments in order to send a message out to those who know where to look. IMO this is not inline with the spirit of the fragment but is rather a cool hack.