I just read Quick Calculus: A Self-Teaching Guide, 2nd Edition by Daniel Kleppner and Norman Ramsey. I found a few errors, but couldn’t find an errata listing online, so I’m documenting them here for future reference.

1. Page 107, Frame 206. The quotient rule as it’s initially expressed is incorrect. The correct version is stated at the bottom of the page and also on page 102, Frame 194.

2. Page 173, Frame 330. None of the options listed are correct. The correct answer is 15

3. Page 187, Frame 355. The initial expression of Simpson’s rule is confusing. It should be:

   ∫_A^B y dx = 2/6 Δ (y₀ + 4y₁ + y₂ + y₂ + 4y₃ + y₄ + … + y_N-2 + 4y_N-1 + y_N)

Errors in technical books annoy me because I spend way too much time trying to figure out why I’m mixed up. Not having a published errata online annoys me even more. See Mark’s book for an errata page done right.

All ranting aside, Quick Calculus is an ideal resource if you’re looking to brush up on the basics of Calculus. It’s short and interactive, yet it doesn’t sugarcoat the material.

I missed the Milwaukee Malayalee Christmas Party this past weekend, but Lisa sent me pics. Can’t wait to go home for the holidays…

Ooops - I just realized that I forgot to link to the pics from our Reunion back in August. At least I got them posted before the end of the year.

Researchers at my alma mater have shown that mice who have been bred to run long distances show increased activity in ‘craving’ regions of the brain when they’re denied access to their running wheel (Be sure to check out the Quicktime video on that page). The addiction of running is physiologically similar to other addictions. Maybe that explains why I was out on the East River Path in 29 degree weather tonight.

I ran two more races this past week - the Race to Deliver 4 mile in Central Park on Sunday and the Turkey Trot 5 mile in Prospect Park yesterday. The Race to Deliver was crowded with 6000 or so other runners and I spent most of the first half of the race just swerving around everyone else. I never quite got into a groove, but I was still able to finish in 32:34.

The Turkey Trot was much more fun. The first half mile was crowded, but the rest of the race was smooth sailing. I’d never been to Prospect Park before and I was pleasantly surprised by its beauty. New York City is certainly blessed with great public parks. Anyway, I ran the last 2 miles in 15 minutes to finish in 40:12. I hope to break the 8 minute barrier soon…

I ran the NYRR Cross Country Championships this AM in 26:48 for 5K. My last cross country race was 15 years ago as a senior in high school. Wow, writing that sentence makes me feel old :-) In those days, I could run 5K in 19 minutes easily and I thought that 7 minute miles were slow. Ahh, to be young again! The NYRR run is held at Van Cortland Park, a beautiful oasis in the Bronx and the race starts out deceptively flat. You run along the edge of the some soccer fields for the first mile and then enter into a forest where nothing but steep unrelenting hills await you. I did great on the flat part! The hills kinda killed me, but I’m happy to report that I fought off strong urges to walk up some of the nearly vertical hills around mile 2. I gotta thank Harish for pushing me through a grueling 9 mile workout last weekend which left me on the edge of death, but gave me the confidence to keep running today! Finally, near the end of the hills, I started to feel stronger and the next thing I knew we were out of the woods and circling around the starting line where the women’s race was getting ready to begin (had to pick it up there!). I turned the corner to the finish and started my sprint which was longer than I expected. I was about to pack it in and coast to the finish line when I saw that the clock was nearing 27. Gotta break 27, gotta break 27! Woo hoo! This may just be some residual endorphins talking, but I’m gonna break 20 minutes for 5K again someday.

I ran the Marine Corps Marathon yesterday and can now confirm that Hitting the Wall is a real phenomenon. I finished about 5 minutes faster than I did in Chicago (2000), but I was really hoping to break 4:30. Everything was going great through the halfway point (2:11:48 - 10:04 mpm) when a few doubts started to creep into my head. I’m only halfway? I gotta do this again? Somehow I was able to make it through to mile 17 at 2:55:30 (10:19 mpm) before things really fell apart. I remember it clearly yesterday and it seemed to be an instant replay from Chicago. I started thinking about how much further I had to go and how tired I already was. Then I think, well, maybe I need to rest up so I can finish strong, huh? Maybe I should walk through the next water break - that won’t be such a bad thing, right? And then the next thing I know, I’m walking more than I’m running. Once I start walking, I’m done. The key is not to think about how much further you have to go, but rather to take it one step at a time, but that’s obviously easier said than done. The marathon is not a rational thing - if you think about it and you let your rational mind make decisions for you, you’ll never accomplish your goal.

I’m still quite happy with finishing. I’m sore all over, but in that satisfying kinda way. I was able to take the train home yesterday and even made it to work today. And unlike 2000, I’m motivated to keep running, although I’m going to stay away from marathoning for a while. My left brain isn’t ready for it.

Dilu and Amit raced 26.2 miles in the Chicago Marathon today and both finished with amazing times. Dilu completed his first marathon in 4:19:18 which is less than 10 minute miles and almost an hour better than my first one. Amit ran the 2000 Chicago Marathon with me and finished in 4:30ish, I think. He ran today in 3:57:32 - breaking that elusive 4 hr barrier. Nice job guys!

Now I’m excited for the Marine Corps Marathon - 2 weeks to go. I’ll never be able to match Amit and Dilu, but I’m going to try to beat my Chicago time of 5:13:30.

MarkD informed me that unregistered users couldn’t add comments. Turns out it was due to some extra quoting of query variables that has been fixed in more recent versions of OpenACS, but I’ve been too lazy to update. The good news is that all of you who’ve been dying to tell me off can finally do so!

Bhavesh responded to my seemingly irrational exuberance about OpenACS asking, “What’s the excitement about OpenACS?”

There are much better answers to this question, starting with Why OpenACS?, by my web host Cathy Sarisky, but here’s my super brief answer.

OpenACS is a toolkit to build online communities, that is, sites which value users and their contributions. OpenACS provides applications which allow users to create and manage content - applications like forums, photo albums, blogs, calendars, wikis, and file storage areas. Users can obviously create content in these areas, but they can also be given extra privileges to moderate the content or grant privileges to others. So, administrators can delegate the management of the site to those who are most invested in it - the community. Currently, OpenACS’s main focus has been at educational institutions (MIT, the University of Heidelberg, and many others) where it’s ideally suited for course management. It’s currently not polished enough to be used out-of-the-box unless you’re comfortable with Linux system adminstration, but improvements are being made in that area.

This site is built on OpenACS, but I barely scratch the surface of the features available. I plan to add more stuff soon, but OpenACS is in the midst of releasing its next version, so I’m concentrating my extensive free time in that endeavor. Once OpenACS 5 is out, I’ll upgrade this site and then add some of the bells and whistles.

To be honest, I’m not sure that OpenACS is the right application if you’re just looking to build a personal website. Movable Type is much more suited to that purpose. OpenACS is useful when you want to allow a bunch of users to each have complete control over their own personal websites, yet also allow those users to interact with each other, perhaps even aggregating content from multiple users in one place. So, if you wanted to create a service that competed with TypePad, you could use OpenACS to do that.

OpenACS’s main power lies in the fine-grained control that it gives you. Every object and area can be controlled the way you want, so the level of control that users have is up to you. The database API is clean and gives you full access to the database of your choice - Oracle or PostgreSQL. Your hands aren’t tied. The templating system is intuitive yet offers a lot of features for more complex, specific cases if needed. A lot of work is currently going into building and improving an automated testing framework. There are plenty of other reasons why I love OpenACS and I’ll write about them some more as examples of them come up.

In short, OpenACS is the way for me to get things done on the web.