Commentary

This doesn't really fit under "about" but then again, it doesn't really fit anywhere. This will usually be a page for miscellaneous comments.

Apr10 | 19
Oct09 | 25
Mar09 | 4
Feb09 | 21
Nov08 | 3
July08 | 17
June08 | 3 | 13 | 27
May08 | 31
Apr08 | 13 | 30
Mar08 | 3 | 5 | 8 | 12 | 21 | 31
Jan07 | 7
Oct06 | mid

R and LaTeX: OS X vs. Windows | April 19th, 2010 | permalink
I wanted to run over some differences between R and LaTeX on a Mac (OS X) and on a PC (Windows XP). Generally I am indifferent to operating systems but in the case of these programs, I strongly prefer the Mac versions.

R. Below are screenshots of R on a Mac and R on a PC (click for larger images, and hover over the images if you are not certain which is which). The PC version has each smaller window contained within the larger R GUI window while the Mac version allows its smaller windows to be moved around independently. This property of the Mac version makes it easier to work with R and other programs simultaneously. The coloring scheme is also substantially more appealing on the Mac versus the PC, providing more obvious structure to coding in the program editor.

LaTeX. Images for LaTeX in each platform are shown below (note that two source windows are open on the Mac version since I usually use the "include" command in LaTeX). Similar comments to those made regarding R hold true here as well. The coloring scheme is preferable on a Mac, though much less dramatically than the case of R (it is probable that some prefer the PC coloring to the Mac coloring for LaTeX). More importantly, there are a number of user abilities available on the Mac version that are not available on the PC version: (1) The Mac version allows the screen window to be "split", (2) After typesetting on a Mac, a new window automatically opens to show the updated PDF (or updates the already open PDF), (3) a user can click on the PDF, which enlarges a section of the window for easy spot-checking. See the SCC LaTeX 1 presentation for additional details and clarification.

Disclaimer. (1) I may be introducing a bias through the screen captures; a larger screen was used for the Mac shots. (2) I have never purchased a Mac, though I currently have one that a friend loaned me that I use regularly, and I also use one daily in my office. I have purchased two PCs and still use one of them (but never for R or LaTeX unless I have no option). (3) This brief post is not intended to examine all differences, only a few major aesthetic and usability components. I have not tried out the variety of PC version of LaTeX, though from my understanding they do not differ dramatically in usability or aesthetic qualities.

Open Intro | October 25th, 2009
One of my ongoing projects is in the production of an open source introductory statistics book. We call this project Open Intro. I am pleased to report the project is proceeding very well. We released a draft of Chapter 1 in September and will release Chapter 2 on November 23rd. We also have recently expanded to include four additional people in the project: Filipp Brunshteyn, Meenal Patel, Mine Çetinkaya, and Rob Gould.

For additional details on the project, please visit openintro.org If you have any questions on the project, please send me an email.

Share a book, save a tree, and get another one yourself | March 4th, 2009 | permalink
PaperBackSwap.com is an online bookswapping site that offers a chance to send old book to fellow book lovers. (Brandi brought this site to my attention.) I sent out over half a dozen books within a couple weeks of joining, and now have credits to order books myself.

While the benefits of getting new books is one thing, there is also the bonus of sending a book to someone knowing they actually want it -- they requested it specifically. Not only does this help them but I've found it useful for uncluttering my bookshelf while it also reduces waste.

Of the books I've ordered on PaperBackSwap, all have been in good condition. Additionally, book credits can be swapped for DVD or CD credits on the sister sites SwapADVD.com (3 for 2) and SwapACD.com. While these sites aren't yet as large as PaperBackSwap in the community and selection, there are still plenty of good items available.

Credit Protector -- the scam | February 21st, 2009 | permalink
When I was checking my (Citicards) credit card statement, I noticed a link for a "free" $50 in Visa gift cards, which I of course clicked immediately. The promotion was for card holders who would enroll in a program called Credit Protector, which I dug into a little bit. Here's what I found...

First, let me describe the program. For paying a $0.85 fee for every $100 on your new balance each month, you get some credit protection benefits. On the surface, it sounds like the premium is only 0.85% on purchases. That's true for card holders who pay the bill off completely each month, i.e. the people who don't need credit protection. But for those who have rolling debt, the so-called new balance includes all of last month's remaining balance. So really, the 0.85% is paid monthly for these consumers. (Program details).

In short, anyone who has a rolling credit card balance and takes this promotion gets scammed. They pay an extra 0.85% every month on every purchase... that is worse than adding 10.2% to a person's APR. The compounding interest for each month actually pushes the the equivalent APR increase closer to 11-14%, depending on the original APR. For instance carrying $9,000 in debt and enrolling in Credit "Protector" will result in $1000+ of extra debt annually.

Basically, this promotion is probably going to land a lot of people who are already in a precarious situation into a worse situation. Those people most interested in credit protection, whatever credit protection really is, will be the bunch who enroll. Little do they know they've been tricked into paying much more to the credit card companies.

So which party really needs protection? And who is to blame for consumers being unable to get out of debt? Is it the irresponsible consumers or the underhanded creditors? I'm sure this article suggests which way I lean.

Driving an old car to save new car production emissions? | November 3rd, 2008 | permalink
One argument from inefficient SUV owners is that extending the life of their beater (or even their new car) is more efficient than buying a new efficient vehicle since it takes energy to produce vehicles.

The Google Answers page that I came across resulted in many useful and credible sources of information. (Two of those sources: 1 and 2.) This led to the conclusion that about 11% of the emissions of the entire lifecycle of a vehicle are the result of production while the remaining 89% are associated with fuel sourcing, production, transportation, and use.

Take the plausible scenario where a new, relatively efficient car gets 35mpg and consider an SUV owner who gets 20mpg. How many driving miles would it take to make up the production of the small car? A little math suggests that it would take about 700 gallons of gasoline or equivalent emissions to make the small car assuming a generous 200k lifespan. That energy would be made up in about 33k miles of driving. That is, a person could buy a new efficient car every 33k miles and still come out even with an SUV driver in terms of emissions.

Verdict: Buy a new efficient car to replace inefficient (non-hybrid) SUVs -- regardless of the age of the SUV. Additionally, selling the SUV to someone who would otherwise buy a new SUV also saves the more energy-intensive production of a new large vehicle.

The same "out with the inefficient" logic also holds true for replacing incandescent (traditional) light bulbs with compact fluorescent light bulbs, even if the bulbs being replaced are new.

The Free Market and Social Justice | July 17th, 2008 | permalink
The present policy of the United States on global warming policy is that the free market will resolve the issue. This policy has a serious flaw. For such a system to work, information about the CO₂ emissions of each product needs to be available to consumers, which it is not. This begs the question, how can it be expected that the average American is capable of determining the emissions produced from a particular good when it seems that most cannot estimate the Calories in their food at their favorite restaurant or moca joint? This 'free' market is inhibited by lack of information (and possibly motivation); however, there is a solution to make the market do its job.

A fee and rebate system on carbon emissions (CO₂) that is revenue-neutral would solve the issue by applying a cost to products that emit CO₂ and cause pollution. To do this, a fee is applied to products that result in emissions of CO₂, i.e. electricity, gasoline, and natural gas. For example, the fee could be 1 extra cent per kilowatt-hour of electricity or an extra $0.40 on a gallon of gas. Any revenue from these fees would then be split evenly and returned to each taxpayer. The reasoning goes that since the public pays an environmental and health cost for pollution and CO₂ emissions, people who inflict a greater burden on the public should pay more for that privilege, proportional to their emissions. Under this system, there are two groups of people. A person might ...

The fee/rebate system is certainly reasonable for anyone in the first category; their only change is receiving more money from the system than they pay in fees. But is it reasonable for a person from the second? What most people don't realize is that thousands of Americans die annually from pollution and millions more are subject to diseases, asthma, or other inflictions partially induced by pollution. Additionally, everyone will have to deal with climate change. Does it seem so unreasonable that people who pollute more than the average should pay everyone else for that privilege? Additionally, individuals in this second category may make their way to the first by becoming more energy efficient and/or using renewable energy to reduce the burden on society.

In the next few years, some system will be put in place in the United States to help reduce pollution and CO₂ emissions. The best publicized is a cap-and-trade system, which allots a specific or maximum amount of permitted emissions to companies that currently emit CO₂ and other pollutants. These 'emissions credits' may be either used or sold for profit. Although this would have some positive effect, such a system is inherently flawed. A cap-and-trade system would be highly beneficial to companies that currently cause the most pollution, and it would punish those companies that already have made changes by not granting them as many emission credits. It would also stiffle competition since new companies may not be granted emissions and must pay their competitors for that privilege. Instead of granting companies the right to place a burden on society and sell that privilege for profit, a fee/rebate system lets the public sell that privilege. For additional information on such a fee/rebate system, I would recommend visiting carbontax.org.

Yellow cake | June 27th, 2008
The one review for Duncan Hines Yellow Cake Mix on Amazon.com:

	17 of 19 people found the following review helpful: Disappointed, December 24, 2007 By MoLaw (Can Sitty, Misery) - See all my reviews Obviously, the price is right - so that's 1 star right there. And the convenience of super-saver delivery spares me I don't even know how many trips to Niger. That's another star. However, try as I might, I could never get this stuff to enrich to fully weapons-grade. If it worked half as well in my ballistic missiles as it does in my research reactor, it'd be 5 stars. Maybe you'll have better luck. It's possible that my centrifuge is hinky.

(Yellow cake is a form of oxidized uranium that was heavily discussed during the build-up to the Iraq War and also in the Valerie Plame fiasco.) This same user's other reviews as well as reviews on Uranium ore or the Badonkadonk Land Cruiser/Tank are also mildly entertaining.

Owned by the car | June 13th, 2008 | permalink
Over the last two years I've abandoned ambitions of owning a car. This isn't solely for environmental concerns, although there are many, but largely for cost and convenience. After a small amount of thought, it's clear that owning a car is very costly: purchase price (>$2000), insurance ($650/year), maintenance (average of $500/year), parking ($2500 annually for a parking spot), gas (>$500/annually), plus the many miscellaneous charges that arise when owning a car. With those costs of roughly $3000/year, add the stress of having an expensive item that may be easily damaged. I've found renting a car when I need one to be a much more economical and low stress option. When a real need for a vehicle does come up, I'll be able to afford the taxi with all the money I saved, i.e. didn't spend. As for my main transportation, the bus, I get a lot of reading and work done during my 25 minute commute to/from campus.

Polling error | June 3rd, 2008 | permalink
Reading over the polls, I noticed the following comment on CNN:

	The new USA Today/Gallup survey shows [Obama] with a 5 point advantage over McCain among likely voters, 49 percent to 44 percent. That margin is just outside the poll's 4 point margin of error, meaning Obama appears to hold a slight advantage over the Arizona senator with five months remaining until voters weigh in at the polls.

The margin of error for the support of a single candidate is 4 percent; the difference does not have the same error since the proportion of people who support McCain is negatively correlated with Obama's support. That is, if Obama's support is actually 2 percent lower, it is likely McCain's support is about 2 percent higher. So for the difference to be truly significant, we have to see a larger point advantage.

Rental insurance | May 31st, 2008
Heading off for vacation to Sequoia and Yosemite National Parks next month, I had to rent a car. In the spirit of limiting costs, I was worried about the vehicle insurance. That was until someone brought it to my attention that some credit cards will provide insurance at no cost as long as the full rental is placed on their card. I am happy to report that the credit card I use has this policy.

Sportsmanship | April 30th, 2008
Every now and again there is a nice feel-good story. And by "now and again" I mean rarely in today's media. I found this one when scanning the web content sharing site digg.com. You may need to register on nytimes.com to view the article, which is free, and I think worth the time. This story seems well-liked by many on digg:
"my view of humanity just went up a little." -demigod
"This should be required reading for all young athletes." -hogfoot

Windows | April 13th, 2008
My computer, running on Windows, restarted without prompting me a couple days ago. This feature is presumably to keep my computer updated but also caused me to lose unsaved documents since it restarted. I was actually in the middle of a VOIP call as well so my computer also hung up on that person. The line went dead and I just heard the sound of Windows shutting down -- there was no warning. I tried to contact Microsoft support to try to address the problem but they wanted $59 to simply reply to my email.

CPR -- hands only | Mar 31st, 2008
Great news for those who feel compelled but hesitant to perform CPR. The American Heart Association now is supporting hands-only CPR as an alternative claimed to be as effective as conventional CPR. Read more in this CNN article or in this informational on how to perform hands-only CPR (it takes 2 minutes and is very straightforward).

Getting spammed | Mar 21st, 2008
It has become all too apparent that listing my email address on my website as text or a link has made it potentially subject to 'spam bots' (bots that scour sites for email addresses). Recently another email that redirects to me has been hit with a lot of spam -- about 30 yesterday alone. This morning I promptly removed any text with my email address from my website and replaced them with images that display my email, which will not be easy for a bot to read. Now I just need to close that other email address... [April Update: I have taken the same HTML route as Jose and Verghese have with the email addresses on the stat directory. It is still text but harder to grab by a program. And it looks better.]

Google calendar | Mar 12th, 2008
Too many things are going on so I've taken up Google calendar. Now I'm having an internal debate: should I put my calendar here for all to see? Granted, it's not very exciting. A class here. A class there. Maybe office hours after class. Keep an eye out and you may catch a peak of a new calendar link as I give this more consideration and begin to play with the calendar sharing features.

Excel as a statistical tool | Mar 8th, 2008
Excel's internal tests apparently are nothing to write home about. The most basic test, a 2-sided Z-test using ZTEST(), is not properly computed in Excel. It claims to "return the two-tailed P-value of a z-test" when in fact it returns the p-value for a one-sided Z-test (H_A: p < p₀). This occurs in Excel Version 11.2.5 on a Mac and also Professional Edition 2003 on XP (I have not checked other versions).

Bottled water | Mar 5th, 2008
Although a bit crass, Penn and Teller take a look at bottled water. It seems to be accurate from what I have previously read on the topic. I'm also a big skeptic on plastic bottles leaching chemicals if the bottles are reused. If Dasani can put tap water into bottles and not have leaching problems, so can I. Leaching myth info is posted on snopes.com and about.com.

Open-source statistics | Mar 3rd, 2008
Some New Zealanders appear to have started an open-source statistics book in late 2006, which has since stalled. The one completed chapter looks pretty good. I think this justifies a trip down to New Zealand to investigate the matter further.

Skype | Jan 7th, 2007
Free calling to any phone in the US and Canada is now done, but Skype has offered a very fair alternative -- pay $30 for a year of unlimited long distance calling. [Update: unlimited calling within the US/Canada is now $3/month.]

Free books online | mid-Oct, 2006
Dive into Python
Practical Regression and Anova using R (Link provided by Mine.)