Trouble with figure previews in TikZiT
I recently decided to give the open-source TikZiT a try for drawing TikZ-based figures. While the feature set TikZiT can handle is a relatively small subset of TikZ's capabilities, it seems to do what it does quite well. I'm running version 0.8.417 on Mac OS 10.6.8 (Snow Leopard), and have only encountered one significant issue so far. Out of the box, everything seemed to work as advertised except for the previewing function. When I asked for a PDF preview to be generated by pdflatex, I'd receive only the relatively unhelpful error message "AN ERROR HAS OCCURRED, PDFLATEX SAID:"
with no indication of what it may (or may not) have said. I have TeX Live 2011 installed (though I see 2012 was released last month), with pdflatex in my path. I did what I could to debug the problem, but a Google search for the error returned no results and the error itself didn't give much to go on. So, I contacted the developer of TikZiT, Aleks Kissinger, who got back to me with the solution within a few hours.
Apparently TikZiT doesn't necessarily use the actual path variable set in your operating environment, but rather searches the two files ~/.profile and ~/.bashrc to attempt to learn the location of pdflatex for itself. The very simple solution was to create or add to one of these files, with a line similar to
export PATH=/usr/texbin:$PATH
in order to tell TikZiT to look in /usr/texbin for the pdflatex executable. Once I'd put that command into my newly created ~/.profile, I didn't even have to restart TikZiT to get a preview of my graph.
New Calgary Transit CTrain map
Recently Calgary Transit has released a survey about their proposed new synoptic map for the CTrain. On the whole I think it provides a significant improvement over the old version, however I had one concern with it, related to the representation of the downtown stations.
Of the nine stations in the Free Fare Zone of Seventh Ave, seven service both train lines but only one direction of travel; three have only westbound trains, and four only eastbound ones. The new map, on the other hand, indicates that three of these stations service only the Blue Line -- presumably both directions of it -- while the other four are for Red Line trains.
I suppose that the meaning is somewhat clear to people who use the system regularly, and is even somewhat intuitive to those who know that along Seventh Ave the westbound stations are on the north side of the street and the eastbound ones are on the south. Nevertheless, I think that to the people who will be most in need of the map, the meaning will be not at all clear until they are physically at the station, and perhaps not even then. It really looks as if you could head to 4th Street Station and catch a Blue Line train heading to the Northeast.
I tried to describe this deficiency in the comments section of Calgary Transit's survey, but after submitting it I decided to try my own hand at solving the problem:
I'd hope for a more graphically pleasing split of the lines on either side of downtown, and ideally the split would come after City Hall since it does serve both directions, but I think that this does a much better job of accurately portraying the layout of the train system as it pertains to the question of which stations will let you get where you need to go.
Rooting Android… Finally!
I've had my Xperia X10 for quite awhile now. In fact, since the day they first became available in Canada. I've wanted to root practically since the beginning -- the supposed ability to do so was one of my primary drivers in choosing an Android smartphone. Nevertheless, finding a distinct lack of custom ROM support for the X10 combined with relatively few non-ROM-flashing reasons to root, I've put it off over and over.
This evening though I finally got fed up enough with the bloatware on my Sony Ericsson Xperia X10 (running the stock Android 2.3.3 from Rogers in Canada) that I decided to root it. This is a brief chronicle of my experience, primarily for my own future reference. If it turns out to be useful to you too, then all the better.
Even though it thankfully turned out not to be necessary, I have to point out that the first thing I did was perform a backup of everything I could, using the Backup and Restore program.
With that out of the way, I followed DooMLoRD's instructions on xda-developers, downloading version 4 of his zergRush-based rootkit along with starquake64's bash script for Mac OS. Since I already had the Android Debug Bridge installed as part of the Android SDK, and had my phone set to allow USB debugging and installs from unknown sources, the shell script just ran without issue.
So far I've managed to free up a bit of internal space by finally moving some unused bloatware (Timescape, Postnote, Facebook, to name a few) to a backup folder on my SD card, based on a list of removable software (xda-developers again) and a suggestion from the unofficial Xperia X10 blog. My next step was to install Titanium Backup Pro, which is uploading about 400 MB to Dropbox as I type. After that I'll keep working my way through lifehacker's guide to Titanium Backup, then hopefully on to more rooty goodness.
Triple-slit update
A paper titled Analysis of multipath interference in three-slit experiments appeared on the arXiv last week from Hans De Raedt and collaborators, in response to the research presented by Urbasi Sinha in the seminar I previously mentioned about triple slits and Born's rule. I haven't had time to give it an in-depth reading, but the general message is a claim that, based on Maxwell's equations, one should expect a non-zero three-slit interference term in general, contrary to the assumption motivating Sinha's experiment. Nevertheless, they say, in certain experimental setups a very good approximation is that the three-slit term will vanish.
Since Sinha used one such setup, the fact that no three-slit interference term was measured is to be expected according to both De Raedt and Sinha. De Raedt goes on to say though that this is just a coincidence based on their choice of experimental setup, and cannot be used to draw any conclusions about Born's rule.
IQIS Seminar: Triple slits and Born’s rule
Urbasi Sinha recently gave a seminar talk at IQIS about her test of the Born rule using a triple-slit setup, as well as an implementation of a single-qutrit system using the same setup. The bulk of the talk was based on an arXiv posting, and while it contains no earth-shattering results (Born was right, probably!), the motivation and experiment are quite interesting.
Born's rule is so ubiquitous in quantum mechanics that I had actually forgotten it had a special name and had to look it up before the talk; it's the rule which tells us that the probability distribution for a quantum system is given by |Ψ|². We know of course that this rule holds very well in a wide variety of situations, but then we know the same about Newton's laws, and look what happened there.
The fundamental principle being examined in the experiment is a rule for describing interference terms when combining probabilities, and was originally discussed by Rafael Sorkin in 1994. The original double-slit experiment demonstrates the wave nature of light (and other particles) by showing that the probability distribution resulting from a photon's passing through two slits is not equal to the sum of the probability distributions of having passed through one of the slits but not the other. The difference between these two possibilities is the interference term,
I(A,B) = P(A,B) - P(A) - P(B).
That is, the interference arising when slits A and B are both open is given by adding up the distributions when the slits are each open on their own, P(A) and P(B), and then subtracting the distribution arising when they are both open. If there is no interference, then I(A,B) vanishes. This is what we naïvely expect with our classical intuition for a single particle, and it is the fact that this is not the case (among other things) that gave rise to quantum mechanics.
What if there are three slits though? The corresponding rule is
I(A,B,C) = P(A,B,C) - P(A,B) - P(A,C) - P(B,C) + P(A) + P(B) + P(C).
If we assume that Born's rule is correct, then I(A,B,C) = 0. Running an experiment in which single quantum particles are sent through a three-slit apparatus can tell us what nature yields for I(A,B,C), and if it doesn't equal zero then something new and different is going on!
As alluded to earlier of course, no such violation was found. As far as they were able to determine, Born's rule does indeed hold. An interesting side note is that after the result appeared in Science last year (arXiv listing here), Max Born's son (in his nineties) wrote to the experimenters to thank them for their effort to prove his father's decades-old theoretical prediction.
Separating figures from a LaTeX document
Once again, I've run into something that shouldn't be an issue with a submission to PRA, but which nevertheless is. I generated some plots in Mathematica, but decided to label them with LaTeX. I thought this would be standard, given that it allows for a consistent font throughout the document, but the editors have said that using "commands in the manuscript source file to include axis labeling or other such content to your figures is a problem for us". Whatever the reasons for this, you can't argue with it if you want your manuscript published.
So, can you quickly extract each figure, complete with added labels, into a set of graphics files to be re-included in place of the original figures? Indeed you can! The first step is to use the preview package:
\usepackage[active,tightpage]{preview}
\PreviewEnvironment{tikzpicture}
When you compile with this package active, every instance of the PreviewEnvironment will be rendered on its own page, and anything not in that environment will be suppressed. The tightpage option makes each page of the resulting file just big enough to contain the bounding box of its contents.
One warning: LaTeX labels get lost here, since they generally occur outside of the environment being extracted. This is important if you are, for example, placing a sub-figure label on the image. The first time you compile with preview active everything will look all right because the aux files will still remember the labels from the previous compile. If you start noticing `??' where you expect `(a)', just deactivate the preview package, recompile until things look right, then reactivate it.
The next step is to split the resulting file into a sequence of files, one per page in the original. My first attempt was to split either the postscript or PDF file using a command like
(Not the solution) pdf2ps allfigs.pdf fig%02d.ps
to split allfigs.ps into fig01.ps, fig02.ps, .... Unfortunately, this rasterizes the text, without even antialiasing it, and the result just doesn't look quite right. I was hoping to simply switch to pdf2eps or pdf2pdf for better luck, but at least on my Mac OS X machine these don't exist.
Instead, I found a page detailing a quick solution using Automator that spits out each page of a PDF into its own new PDF. The final step was simply to replace all of my lovely TikZ code with simple \includegraphics commands.
UPDATE: It turns out that the Automator solution trims the images a little too closely, and parts of the output PDFs are missing around the edges. I tried several other scripts and online PDF splitters, but ran into one of two problems with each. Either (a) the "split" PDFs contained only the first page, regardless of the output range asked for, or (b) the resulting PDFs were ever so slightly cropped, as with the Automator script. Finally I downloaded a program, PDFsam (PDF split and merge) which did the trick.
Finally, it turns out that I had to convert each of the individual PDF files to EPS format for submission to PRA. I accomplished this quickly and easily with a nice little script that runs Ghostscript.
Moustachioed Mayor Nenshi
OpenFile Calgary is looking for pictures of Calgary Mayor Naheed Nenshi sporting digitally added moustaches. Their goal is to draft him into growing a moustache for Movember, and I decided to try my hand at coming up with an entry.
I used a cc-licensed picture posted by flickr user 5of7, and have likewise licensed this minor derivative work, for whatever it's worth, under a Creative Commons Attribution-ShareAlike 2.0 Generic License.
You can find this and the other images people have submitted on the OpenFile Moustached Nenshi, a sampling page.
A letter to my Member of Parliament
I know that in the current political climate there is little chance of anyone with a dissenting opinion having that opinion heard, but if you don't try you can't complain, right? That's why I have modified a form letter on the Green Party website and sent it to my M.P., Michelle Rempel, in the hope that maybe, just maybe, enough constituents will complain that the Harper Government will consider a few modifications to their omnibus crime bill before passing the bad with the good.
Dear M.P. Rempel,
I am a voting constituent in your riding, and as such I would like to clearly express to you my concerns with and opposition to Bill C-10 – the omnibus crime bill.
This legislation is severely flawed. There are of course some parts of the Bill that are worthwhile, but I believe that many of the others will only undermine, overburden, and shame our entire system and ideal of justice in Canada. I do not believe that a teenager convicted of possession of a few pot plants should be treated more harshly than someone convicted of sexually molesting a child.
In Canada we have a correctional system, not a penal system. I do not believe mandatory minimum sentences serve the best interests of justice. This legislation will fill our jails with people who should not be there, costing the tax payers far more money than it is worth for relatively minor, non-violent crimes. My idea of a good, honest, decent Canadian society does not jive with the idea that there is a one-size-fits-all approach under which, by law, no extenuating circumstances may ever be considered (even though, of course, they will still exist), or that minors should be publicly identified and therefore hounded and humiliated by the media, blogs, and peers in a manner that they will never be able to escape even long after they have served their time.
I have seen the news reports from the United States. I know this approach to justice has been tried there, and it has failed. They have by far the highest rate of incarceration per capita in the world, roughly 25% higher than than Rwanda and over 30% ahead of Russia, who hold the second and third spots, respectively; see the International Centre for Prison Studies website at
http://www.prisonstudies.org/info/worldbrief/wpb_stats.php?area=all&category=wb_poprate
where we rank 128th in the world for percentage of incarcerated population. This is a list I have no desire to watch Canada climb, especially at a period when the crime rates are as low as they've ever been in your and my lifetimes.
Furthermore, as a taxpayer, I am very concerned with what this legislation is going to cost me. I understand that each new prisoner will cost an additional $108,000 per year of my money. The new prisons that will need to be built to house these extra prisoners will also cost billions more, while creating relatively few long-term job prospects. In this time of deficits, this is not how I want my government to spend my money.
As my representative in Parliament, I am therefore calling on you now to faithfully respect the wishes of your constituents and vote against pushing through Bill C-10.
Sincerely,
Michael Underwood
If by any random sequence of events I get a response or, better yet, some change is effected, I'll post an update....
What makes music good?
There are many qualities that determine whether a given song is considered 'good' by one or more people, and obviously the designation is quite subjective. I'm sure many people have studied and thought about this from scientific, philosophical, and social points of view far more than I have, and perhaps I'll try to learn about some of those at some point. However, an idea just popped into my head and I wanted to get it written down before I forgot about it. I think the following makes sense, based on at least three minutes of semi-distracted consideration.
Part of what leads you to think a song is good is that having heard some portion of it, you feel you could have predicted what follows, but you didn't.
There must be many caveats I haven't yet thought about, and one or two issues that do seem obvious -- for example, a song's being too predictable is often what leads it to be boring. I think that's why it's important that you don't actually predict it, you only feel as if you could have after you've heard it.
A letter to the broadcast consortium in Canada
I just emailed the letter below to members of the Broadcast Consortium, with regards to Elizabeth May and the Green Party's scheduled exclusion from the upcoming Leaders' Debates. I hope I didn't mangle the French version too much! As I state in the letter, I haven't yet decided which candidate will get my vote, and I don't want to have to decide based on incomplete information or biased televised debates.
It's true that I can become informed about any given party through their website and other campaign materials, but to see their leaders respond to the same questions at the same time, as well as to each other, provides a short, concise glimpse of how things might really be in a Parliament containing more than one party. By that I mean, each party speaks of how wonderful everything would be if they were the only ones running the show -- but that's never going to be the case, so how do they behave in a more realistic setting? Besides, how many Canadians are really going to scrape through PDFs and websites of all the parties to become informed, when they could just watch TV for a couple of hours? (Or skip that, and vote how they did last time... Or skip voting altogether... Why don't we skip that line of thought though, I'm trying to focus on people who actually care, or at least want to care!)
There are all sorts of reasons to include the Greens, many of which they themselves outline here, and essentially no way to both exclude them and remain "independent."
To: "Wendy Freeman and Dennis McIntosh" <programming@ctv.ca>, "Jennifer McGuire" <ombudsman@cbc.ca>, "Troy Reeb" <viewercontact.globalnational@globaltv.com>, "Serge Fortin" <info@tva.ca>, "Radio Canada" <ombudsman@radio-canada.ca>
Re: Inclusion d'Elizabeth May aux débats de cette élection / Inclusion of Elizabeth May in this election's debates
Version Français ci-dessous.
-----------
Dear broadcasters,
I have yet to decide my vote, and I certainly want to hear what Ms. May has to say on behalf of her party alongside the other leaders (including Mr. Duceppe, even though I am not eligible to vote for his party) in order to cast a ballot that is as informed as possible!
I hope that the banning of Ms. May is a poorly executed publicity grab, designed to drum up interest in the debates before "changing your mind" and adding her to the process. I can't think of any other line of reasoning for her exclusion that maintains journalistic integrity (not that it is particularly well maintained in this version). While the Green Party may not hold a seat in Parliament, it does represent almost seven per cent of the voters who turned out for the last election, and current polls show that roughly 10 per cent of Canadians support the GPC.
You have a unique opportunity to influence the outcome of this election, whether that is your intention or not. I'm sure you've heard all of the arguments for including Ms. May in the debate, and I value your time so won't rehash them here. Suffice it to say that if your goal is to allow the Canadian electorate a single forum through which to become well informed on their nationwide options on May 2, then Elizabeth May must be included in the debates.
Please reconsider your choice in this matter, as a service to the democratic process in Canada. Thank you.
Best regards,
Michael Underwood
Calgary AB-----------
Chers diffuseurs,
Je n'ai pas encore décider de mon vote, et je veux entendre ce que Mme May a à dire au nom de son parti aux côtés des autres dirigeants (y compris M. Duceppe, même si je ne suis pas admissible à voter pour son parti) pour d'un bulletin de vote qui est aussi informé que possible!
J'espère que l'exclusion de Mme May est seulement pour la publicité, pour augmenter l'intérêt dans les débats avant de vous "changez d'avis" et l'inclure au processus. Je ne peux pas penser à toute autre ligne de raisonnement pour sa exclusion qui maintient l'intégrité journalistique (non pas qu'il est particulièrement bien préservée dans cette version). Alors que le Parti Vert n'occupe pas un siège au Parlement, il représente près de sept pour cent des électeurs qui ont voté dans la dernière élection, et les sondages actuels montrent qu'environ 10 pour cent des Canadiens appuient la PVC.
Vous avez une occasion unique d'influencer le résultat de cette élection, si telle est votre intention ou non. Je suis sûr que vous avez entendu tous les arguments pour inclure Mme May dans le débat, et je la valeur de votre temps donc je ne les reformuler pas ici. Qu'il suffise de dire que si votre objectif est de permettre à l'électorat Canadien un forum unique permettant de bien se renseigner sur leurs options à travers le pays le 2 mai, alors Elizabeth May doit être inclus dans les débats.
S'il vous plaît réexaminer votre choix dans cette affaire, en tant que service pour le processus démocratique au Canada. Je vous remercie.
Cordialement,
Michael Underwood
Calgary AB
UPDATE: CTV sent me an "Out of Office AutoReply" stating that because of "a large volume of inquiries," they might not be able to respond to my email "personally." I have no idea whether this is their standard response, or if there is an increased volume in response to this issue.
Android 2.1 finally released for Sony Ericsson Xperia X10
I just installed the update, and am excited by a couple of things, disappointed by a few more. I don't really want to rant about how long the update took to arrive, or how ridiculous it is to be finally installing it over a year after it was first released by Google -- that's all been covered in plenty of places around the web in the months leading up to today.
My goal here is simply to document a couple of settings I had modified when I first got the phone, then promptly forgotten about until the update undid my changes. I'm expecting this post to come in handy in a year or two when I get to upgrade to Froyo. Two things annoyed me in particular this morning.
Social "phone" book
Sony Ericsson's social phonebook is designed so that you can get in touch with any of your contacts by email, Twitter, Facebook, and yes, even by phone, all in one place. On the surface this sounds potentially useful, but since I personally only ever go into my phonebook in order to place a phone call, I don't like having to scroll through the list of everybody who's ever sent an email to my Gmail account in order to find one of the few dozen people I'm actually likely to call. If I want to send a message to a Twitter contact, I use my dedicated Twitter application. Ditto Facebook and Gmail. Perhaps I'm old fashioned, but what can I say?
So, how can we get around this? Thankfully the option to do so is built in, but it wasn't entirely obvious to me how to find it since it's not accessed via the standard Menu key.
To change which of your contacts are listed in your phonebook, go into the "View contacts" menu, accessed by the button to the left of the search bar. Once in the menu, it becomes quite obvious how to show only those contacts that you are able reach on the phone:
Checking that box will return your phonebook to being just that. There are other options in this screen as well, that might be useful for showing more people whom you may want to contact by other methods, without needing to see every email address that Google has decided is one of your contacts over the years.
Non-native SMS application
I have been using the free chompSMS for quite a while, and had forgotten that when I first installed it I started receiving two notifications for each SMS I received -- one from the built-in, unremovable Messaging application, and one from chompSMS. Again, I had solved this problem once months ago and quickly forgotten how. This one does make use of the standard Menu button, and in fact is not that tricky. My downfall initially was in thinking that the messaging alerts were a system setting, instead of a setting of the Messaging application. I thought this because ending the Messaging process didn't stop it from restarting and alerting me the next time I received a text message, but nevertheless I was mistaken.
To stop it from alerting you, simply open Messaging, press the Menu button, choose Settings when it appears, then uncheck "Notifications." Simple, eh?