Older blog entries for vicious (starting at number 285)

number of unique ips

So I assigned homework in my differential equations class from my diffyqs notes and
the number of downloads from new ips jumped from the regular 90-100 to first week 131 and then this week (when the homework was due, 363. So subtracting 100 from each week for non ucsd downloads (I could check the logs, but I don’t have so much disposable time) I get that approximately 294 (let’s round that to 300) downloads from unique IPs are from my class. There are 180 students in my class, so each student on avarage downloads the notes from 1.67 different IPs (different devices).

On the other hand, the real analysis notes are holding at approximately 200 new ips a week. I know for sure that these are used in at least one class this fall. Given that the jump from summer to fall was from approx 110 to now 200 a week, that would over the last few weeks perhaps lead to up to 350 downloads from new ips that come from students who use that book, meaning about 200 students extrapolating from the diffy qs classes. Since the usual class size for this is 20-40 students, that mean 5 to 10 classes might be using this book. On the other hand, it may simply be students that find the book as a second reference. It would be interesting to know the real number.

Syndicated 2010-10-03 18:07:01 from The Spectre of Math

new genius

I figured I ought to make a genius release before it is a year since the last one, so 1.0.10 is out then. A bunch of minor updates have accumulated but nothing major. Biggest change was that I added possibility to rename variables in the plotting interface so that I can set variable names to those that I am talking about in class. That reminds me to check on the availability of computer projectors in the classrooms I’m teaching in at UCSD.

Syndicated 2010-09-08 08:42:47 from The Spectre of Math

notes

An interesting trend: Downloads from new IPs of my differential equations notes have not spiked in the last week or two, while the real analysis notes have. See (weekly downloads from new IPs, blue is real analysis, red is diffy qs):

(I wonder if the chart will change when I update the the spreadsheet in google docs in the future … we’ll see. The spike I am talking about is of course for the week ending 9/5/10)

My theory is that the differential equations notes are not used as official book in any course (that’s on a semester system), while the real analysis notes are used as official book somewhere. The diffy qs notes tend to spike a little near time of midterms which seems to imply that people use it for extra reference. Also two (yes that’s two) people have bought the bound copy of the real analysis book in the past month, which triples the volume of sold copies. When I taught with my diffy qs notes, I got 5 sales. If it’s the official book, it seems more likely that someone will still buy a hard copy even if they can download and print the book for free (well given cost of printing and simplest binding, it’s not that much cheaper actually).

Syndicated 2010-09-06 17:14:35 from The Spectre of Math

Adobe acrobat is possibly the worlds slowest software

See title. It took about 5 minutes to open a pdf that evince opens in a second or two and that xpdf opens essentially instantly. I was ready to xkill acrobat. Unfortunately for whatever reason evince did not allow me to click checkboxes in a form so I needed acrobat.

Talking about slow applications, the cannon mp560 printer scanner is taking about the equivalent time to scan a single page now. But here I assume it may have to do with the fact that I am using it over wifi.

Syndicated 2010-09-01 19:07:04 from The Spectre of Math

directed acyclic graphs suck for a vcs

DVCS systems like git work on a directed acyclic graph (DAG) model where branching happens automatically with just about any commit. Traditional vcs (e.g. CVS) works generally as a tree where branching must be explicitly done.

Now the argument for DVCS is that you can commit without merging differences done by someone else. The axiom seems to be

Axiom of DVCS: Merging should be done as late as possible.

What’s wrong with that? Well nothing if you are happy for the computer to just blindly merge two very divergent code bases without worrying about interactions of those changes (you kept hacking on feature A which required that function foo works in a certain way, while person working on feature B changed how foo works because he didn’t see anybody use it yet because your use of it was in a branch that the second person of course didn’t look at because he was busy working on feature B). No that never ever happens because all developers always talk to each other about every little change and because every internal function/method/object is completely documented. Yeah.

With traditional VCS, merging is required when checking in. The axiom changes to:

Axiom of traditional VCS: merging should happen as early as possible when divergence is as small as possible.

When everyone continually has to keep up with all the other changes that other people are working on, possibility of screwing up is smaller. Merging other people’s changes into your tree can be far simpler if it was just someone’s morning worth of work with say 100 lines of code. You can actually look at that quickly to review what happened. Not to mention you will have to look at it if there are direct conflicts with your work. Furthermore, if the other person changed how function foo works, you will notice sooner rather than later so you can resolve the conflict before both of you go too far assuming function foo works in a certain way.

I know exactly why DVCS is more popular nowadays. Firstly it is new and new things are always better even if they are worse. Second, it is more complicated, and complicated things must always be better. But most importantly of all: DVCS has a lot more buzzwords. It is distributed, it uses directed acyclic graphs (finally you have a use for some of your CS classes). Lots of things that work are replaced continuously by complicated things that don’t.

Example: I would say the level of the desktop software (Windows, Linux, and Mac) has not improved substantially. It has changed yes. It does lots of graphical voodoo. It allows you to do things that nobody ever wants to do. But if you took a basic desktop from the year 2000 and you simply fixed it to work right, you’d have a much faster, much more productive environment. But fixing things is not as much fun as rewriting a desktop on OpenGL, making windows wiggle, and making a different funky widget set for each application.

Syndicated 2010-08-31 19:28:10 from The Spectre of Math

San Diego wants to kill you (if you walk)

San Diego, especially it seems north San Diego, is one of the worst places to be a pedestrian. Many places without sidewalks, crosswalks, very wide divided streets, etc…

But the worst part of all is the following. Someone had the bright idea that a crosswalk should exist on only 3 sides of an intersection instead of 4. Now, it is possible to go from any point to any point, but it can take very long. Sometimes you need to cross a busy street 3 times just to cross at one point (if you want to do it legally). I am not sure what is the advantage to the cars, but I assume the advantage is very minor. This means that you force a pedestrian to cross more crosswalks OR to jaywalk. That doesn’t seem like a way to improve safety, nor to reduce driving (you know to reduce carbon footprint, etc…) San Diego is apparently among the most dangerous places for a pedestrian. I think I know why. I think the city council hates pedestrians.

Not that the streets here are optimized for cars either. There are so many divided streets, no u-turn signs, etc… If you miss a turn in San Diego you might be likely to drive quite a lot longer (especially in rush hour). Or in some parts, just getting to a store that just happens to be on the other side of a divided street can be an operation involving several traffic lights and breaking a few rules.

Syndicated 2010-08-31 16:00:46 from The Spectre of Math

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