Older blog entries for vicious (starting at number 279)

damn git again

Bitten again … so I now finally noticed that it seems that a ChangeLog file is now out of favour in the GNOME git. People just commit stuff (translations it seems) without anything. Plus when i do git pull, it just spits out a lot of jargon nonsense but doesn’t tell me the important things: Which files have changes. So I don’t actually notice what was changed. I have to go hunt down that information.

I DON’T CARE HOW WONDERFULLY YOU HAVE COMPRESSED THINGS AND HOW MANY “OBJECTS” YOU ARE TRANSFERING. TELL ME WHAT FILES YOU ARE CHANGING.

Even the git browser at git.gnome.org is useless. I wish I had CVS back.

Syndicated 2010-08-31 05:42:10 from The Spectre of Math

I’m the 18th most prolific GNOME contributor?

I’ve looked through the GNOME Census: Apparently in the 6 or 7 years that I’ve not worked on GNOME, I still have not managed to get out of the top 20, at least based on number of commits. By a rough estimate based on time being employed by Eazel, I guess about 1/3 or 1/4 or so of my commits were as Eazel employee. Meaning that probably I account for 1/4 or 1/5 of all Eazel commits to GNOME (that sounds kind of freaky).

What’s even more freaky is that I single handedly committed about 70% as much as Canonical (which had a longer time).

Someone (can’t remember who, I’m reading these blogs while moving half way cross country) said something about that Canonical should have hired some people to just “hack on cool GNOME stuff.” Well, that was essentially my job description at Eazel. So if I managed, over the 3-4 years of really being active on GNOME to have 0.7% of “activity” on GNOME over its lifetime. Than if Canonical would have recruited me (though I was probably unrecruitable by that time) or someone like me, they could over the past 6 years have more than doubled their “contribution.” They would probably have a lot more say in the future direction of GNOME as well. A couple of dedicated engineers are not expensive in the overall scheme of things for a company.

Now number of commits is not the best way to count contribution. I think it’s probably hard to measure Canonical’s contribution to GNOME and it’s likely bigger than indicated by the number of commits.

Still … 18th still? They aren’t trying very hard these days. Must be that they’re all mucking around with git instead of coding!

Syndicated 2010-08-07 04:40:51 from The Spectre of Math

Microtypography

I have been playing around with the microtype package for PdfLaTeX. The results are really nice. Using the font expansion does increase the size of pdf a tiny bit, but not much. It is definitely worth it I think. Overall using the microtype package, I seem to be getting better line breaks, especially in tight places where there are floating figures (where text flows around them). To use simply add
\usepackage{microtype}
to your file, and make sure to use pdflatex rather than latex and dvipdf.

What it does is two things. Firstly it will add protruding punctuation (say periods actually hanging off sides of your paragraphs) to make a more straight looking justification. Furthermore, it may “stretch” the font by a tiny bit on certain lines to get a more even “greyness” of the text (for example, getting more uniform inter-word spacing). It also gives the justification algorithm more freedom in finding better line-breaking points, so you generally get better line-breaking (less hyphenation, etc…). It is the font stretching that adds a bit to your files since you need more copies of the font in the file, but the size increase is not terribly big on large files in relative terms. Still with microtype and PDF1.5, the 2MB differential equations pdf goes down by about 200k compared to no microtype and PDF1.4.

I want to do a bit more cleaning up and perhaps some more fixes before I post updates to the Notes on Diffy Qs, Basic Analysis, and the SCV minicourse. Probably within a few days.

Speaking of the notes, it is interesting that the real analysis notes are now downloaded more frequently by new unique IPs than the differential equations. On average about 30%-40% more. That is surprising, I would have thought that real analysis (taken almost exclusively by math majors) would be less interesting to “the masses,” rather than differential equations on the level of calculus (taken by almost any technical major).

Syndicated 2010-07-14 17:38:25 from The Spectre of Math

Deadlines …

So, early the first fall I was at UIUC (2007), I submitted a paper. It finally got refereed and was accepted in June 2008 (which in retrospect seems pretty quick). I just got the page proofs a few days ago (returned them already). So it took more than two years to get the page proofs. Then there was this funny sentence: “In order to maintain production schedules, we ask that you correct proof promptly and return it within 5 days of receipt.” Emphasis theirs. Apparently, they are in a hurry.

My irony meter broke again. I assume it is OK since it’s the American Mathematical Society. In a more irony/sarcasm sensitive country, I would think they were making fun of me.

Syndicated 2010-07-14 17:12:43 from The Spectre of Math

Homework, copying, and solution manuals

So apparently copying homework makes for lower grades. Duh!

Well it’s something I’ve noticed too. I have taught differential equations at UIUC 3 times. Twice the longer version (286) and once the shorter version (285). First time I taught from the Edwards and Penney book (standard at UIUC). Second time I was making up my notes, but still mostly taught from the book and assigned problems from EP. The third time I taught only from my notes, leaving EP as optional reading only. The last time I assigned problems only from my notes, which do not have a solutions manual (on purpose).

The first two times, with problems assigned from EP, the overall class grades were actually rather similar. However, the third time, assigning homework from my notes, the overall grades were significantly better. In fact, no curve needed to be done on the final at all. There were other factors at play, and material was a little different, but overall I would say the exams were similar enough in both scope, length, and toughness. The differences were seen even on the first exam which was very similar in scope and content for both 285 and 286. And the difference was pronounced, definitely about a grade point higher on average.

My teaching style was not different and I didn’t cover material differently. The type of homework problems were similar. The big difference in my opinion was that more students suddenly had to work out homework on their own. I remember my grader telling me that when problems were from EP that approximately half the class has their solutions more or less word for word from the solutions manual. (yes, students are not supposed to be able to buy the solutions manual, but … they do).

Now I don’t think you will gain many friends among the students by making them work out problems they have no ready made solutions for. In fact I heard many stories how this significantly reduces your student evaluations. My evaluations were comparable across all three semesters, so I guess the fact that the grades were higher because of it cancelled out any negative effects of making students do more work. (I do not read too much into the numbers from the student evaluations, I simply look at the handwritten comments for any useful constructive criticisms, which tend to be rare)

Syndicated 2010-07-09 16:41:43 from The Spectre of Math

Cheating pollsters

A second pollster in recent history got caught cheating. And they get caught by really simple means. When you are a pollster I would presume you know at least a little bit about statistics. You would know that making up numbers by hand will get you caught. Even if it is a matter of a few minutes to make numbers that look credible.

Guide to cheating pollsters:

1) pick the numbers you want in some way, probably look at other pollsters, then add or subtract a little bit, but make sure they add up to a 100. The biggest rule here is: only run a poll that other pollsters have done already. Don’t be suckered into polling something you can’t make up credible sounding numbers for.

2) Write the few lines of code that runs an experiment using your numbers as weights. If you can’t do this, drop me a line I’ll write the code for you in a few minutes for a percentage of your ill-earned money (though you’ll have to pay me enough so that I won’t make more money turning you in to your clients).

Now what could really blow your mind is that it is quite possible that there are many pollsters who do this. The above scheme is very hard to catch. The only way it can get caught is if there is actually some sort of election that actually does get you the actual numbers. Then if all the pollsters are simply copying and fudging numbers that some pollster made up at some point, it is reasonably likely that the election may be a surprise (unless voter intent is changed by the polling numbers).

So let’s assume there are cheating pollsters. Now what is the probability that a cheating pollster is a moron with no understanding of statistics. I would have thought fairly low, but let’s assume that it is 50% in absence of further data on stupidity of cheating pollsters. Therefore given that there are at least 2 stupid cheating pollsters, we should expect at least 2 smarter, much harder to detect cheating pollsters.

Furthermore cheating is probably a fuzzy logic kind of thing. It’s not that a cheating pollster is simply a random number generator (and as we see they’re pretty bad at that too). I assume that a typical cheater actually does some polls and only cheats to cut costs. Suppose that someone wants a daily poll. You could run a poll weekly, then do some sort of interpolation and make up the daily numbers (of course the interpolation is going to be a week late, but most of these numbers do not jump quickly). You should probably factor in somebody elses poll numbers to reduce the error That’s doing 1/7th of the work for the money. Or you could perhaps inflate your sample by running a simulation off of your numbers and other polls. I bet the temptation must be high to cheat since, well run cheating is hard to catch. If you are making up all your numbers, then sooner or later you might get caught.

Syndicated 2010-06-30 16:38:34 from The Spectre of Math

Never use Chase bank!

So I just found out that Chase has just subtracted another monthly payment from my checking account for a car loan that was paid off two months ago. Apparently, once you set up automatic payments, they are impossible to cancel. Also now the account is dead so I cannot access it and they said they can’t cancel payments either. I didn’t quite understand when they will give us back our money. I went to my bank and they said it’s not possible to block future payments to chase without a stop payment fee.

I did cancel the automatic payments (I don’t understand why you need to do that since the account is paid off) when the account was paid off. But that only canceled the April payment and not the May payment, and apparently now they will keep taking our money.

So the lesson is: never, ever, use chase as your bank, including for a loan. In case it is chase that does your auto (or some other) loan, make sure to never give them your account information to set up automatic payment. Perhaps it’s easier to just not get a loan with chase.

This follows their earlier nonsense of taking out more than the payoff amount on the last payment and then having to give us back a check for the difference.

Syndicated 2010-05-27 21:49:41 from The Spectre of Math

Chrome vs. Firefox

For the past month or so I’ve used Chrome to test it out. At first I thought it worked really well. Then I’ve started to discover many annoyances. Firstly, there is no way to “open” files like PDF directly from the internet. Chrome forces you to click a whole bunch of times so that you download the PDF to the tmp directory, then you open it by clicking on the name on the bottom of the screen. This is really, really, really annoying. Especially for a mathematician (or I assume any scientist) who reads many PDFs, DJVUs, PSs, every day. This is enough to make me not want to use it. Whatever stress reduction from slightly faster and smoother browsing experience is totally canceled out by this. I really don’t see how hard it is to save to /tmp and open automatically. I mean browsers have been doing this forever.

Another thing that was worrying me is that saved passwords are not encrypted behind a master password.

The last straw was the fact that it can’t print right.

So back to firefox. Yes it’s slightly slower, and every once in a while I get weird JavaScript errors when using gmail, but it’s way less annoying. It will be nice once firefox moves to separate processes for every webpage. I think that alone does quite a bit to speed up browsing, especially one a multicore machine.

So the result of the fight: Chrome-Firefox is 0:1.

Syndicated 2010-05-27 16:02:14 from The Spectre of Math

Ubuntu vs. Fedora

Before I go off to Europe, I wanted to reinstall my system with an encrypted hard drive since I am getting more and more paranoid about someone stealing it I guess. So apparently I must have been bored since I decided to install Fedora this time instead of simply going with Ubuntu.

One thing I have to say is that I like the default look of Fedora way nicer than Ubuntu. The purple login screen was already giving me nightmares. The other thing that I’m really happy about is that X is actually working perfectly. With Ubuntu it was touch and go and every once in a while it would recognize the wrong number of monitors or wrong resolution. Given that Ctrl-Alt-BS no longer works by default you have to work blind if the login screen appears on a monitor that doesn’t exist. Yes I know you can enable Ctrl-Alt-BS, but that’s only for your login session. I never got it enabled for GDM (I didn’t try to hard, but what I tried didn’t work). I never understood why Ctrl-Alt-BS is so bad that it has to be off by default. It is not a combination I ever pressed by mistake. I’ve also never stabbed myself in the throat with a drill by mistake, or accidentally strangled myself with the phone cord. I assume those are about as likely as pressing Ctrl-Alt-BS by mistake.

Outside of a few minor glitches it is mostly working. One should also note that Fedora installs a broken LaTeX system with a few key files missing due to some license puritanism. For one thing, pcatcode.sty is missing. You have to grab it from a working installation and stick it in /usr/share/texmf/tex/latex/amscls/ and then run texhash. Otherwise the AMS classes won’t work which means that the latex installation is useless to a mathematician. On the other hand floatflt.sty is not missing while it is missing in Ubuntu for licensing issues. Fedora still uses texlive 2007. It seems from Fedora wiki that the next fedora will have texlive 2010.

One thing to notice is that even after enabling extra repositories, there are lots of packages missing. Oh well. The other thing to notice is that the GUI interface for installing packages in Fedora sucks! … no really, I mean IT SUCKS. It feels like it was written by a 12 year old. I’m sure the infrastructure behind it makes CS types all warm and fuzzy inside, but the GUI is terrible! While way too much information about the package version and other implementation details are seeping through the GUI, it gives you NO feedback as to what it is doing. The feedback it is giving you is useless. Sometimes it refuses to install anything without even complaining, the Apply button is just dead. Either make it something like synaptic (which has it’s own GUI nonsense) OR make it user friendly. You can’t simply take the worst of both worlds and stick it together.

The encryption (it’s the whole drive that’s encrypted) is actually reasonably transparent. Copying lots of files (moving my home dir back onto the drive) slowed down the whole machine to the point of being useless, but that might be simiar without encryption, since it seemed most of the slowdown was waiting for the disk. Given that it’s a two core machine, I doubt I will see much slowdown in most tasks.

Syndicated 2010-05-27 15:42:46 from The Spectre of Math

Hockey world championship final game not interesting here

So yesterday it was the final game in the hockey world championship, and it was not on TV here. All I can say is WTF? I don’t normally watch hockey (or any sport), but a finals game I wanted to (especially since czech was playing … and won). It seems that everyone is pretending the championship doesn’t exist simply because US didn’t get far enough.

I had to watch the thing in really bad quality on the internet in danish.

An interesting statistic is that in the past 20 years (ever since Czech republic existed that is), Czech won the most times (6), Canada 5 times, Russia 3 times. So hardly the underdogs nowadays, even if Russia is rated better.

Syndicated 2010-05-24 13:50:35 from The Spectre of Math