clayford.net

 

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2013-02-18

This version of clayford.net is retired. This will be the final post. You'll notice it's been 4 years since I last posted. Partly because I was in grad school, working and raising kids. But also because Blogger stopped supporting FTP to publish blogs, which is how I did it. To keep using Blogger I could have either migrated to a blogspot URL or used their Custom Domain service. Neither appealed to me so I finally decided to start fresh with a new WordPress site. We'll see how that goes.

2009-02-08

 
I'm still learning R and making some progress. I wanted to blog about four things helping make this possible:

1. BOOK - Introductory Statistics with R by Peter Dalgaard. I highly recommend this book for anyone just starting out with R. There are some overly concise sections that will confuse you the first time through. But overall it's a great survey of the R language, giving you a taste of what R can do and teaching some statistics along the way.

2. BOOK - A Handbook of Statistical Analyses Using R by Brian S. Everitt and Torsten Hothorn. Here we have a recipe book of sorts for using R in a variety of applications. 14 of the 15 chapters show you step-by-step methods for analyzing real life data sets. The best chapter though is Chapter 1, an Introduction to R. If I had to teach someone R and was limited to 20 pages of one book (a real life scenario, no doubt!), these are the 20 pages I would use.

3. WEBSITE - Sportsci.org R Tutorial. OK, this is actually a Yahoo group. But the group owner is determined to introduce even the most computer phobic person to R. If you don't want to spring for a book, then download his PDF tutorials and get to work. He's a good writer and very kind soul. His tutorials are completely accessible and free of jargon.

4. PACKAGE - R Commander. This is a graphical user interface for R that allows to run commands from a menu. Ultimately you want to work exclusively from the command line. But this package allows beginners to focus on using R instead of learning R. The best thing, though, is that every time you issue a command from a menu, the corresponding command line input is displayed. So it does indeed help you learn R. I am finding R Commander extremely helpful in my graduate school work. I am required to use R to complete my assignments, but the professor is not teaching us how to use R. R Commander makes it easier for me to use R efficiently to complete my assignments and focus on the material (instead of using all my time reading the R manual.)

2007-12-16

 
I recently decided to install R, a free open source software package for performing statistical analyses. I'm still pretty new with Linux, so I didn't realize what all was involved. I figured it would be like any other program you want to install in Windows: download the install package and double-click it. Not so with this. As this helpful page explains, you first have to modify your "sources.list" file and add the site from which you will download the R files. But to do that, you have to go to a terminal window and enter a "sudo" command to get permission to modify the "sources.list" file. After you do that, you then run the "apt-get update" command and then run a command to install R. Oh, but I forgot -- before you can do that, you have to type a couple lines for security key access. So if you do all that, the install goes as planned, right? Well, no, not if you don't have certain dependencies installed. What I lacked was "libgfortran0". No problem. I'll go to the Ubuntu package manager and get it. But wait, it wasn't there. After about an hour of googling and Ubuntu forum searches, I finally found it here. As irony would have it, I simply had to download "libgfortran0" to my desktop and double-click on it to install it. Then I could run the install commands from the terminal to install R. Usually installing a new program in Ubuntu is super simple. But this time around, wow, what an ordeal. Hopefully learning R won't be nearly as frustrating.

2007-09-18

 
Norton Antivirus blows. Last night I got a little pop-up message asking if I wanted to run live update. "Of course," let's stay-up-date and protected from all the badness out there. So I run update and it downloads one item called an "event driver" (or something like that). I install the update and immediately lose my internet connection. Every attempt to repair it gave me the useful message "Failed to query TCP/IP settings of the connection. Cannot proceed." Fortunately I also have Linux installed on my PC. So I booted into it, hopped on the internet, and searched on that phrase. The fix, thanks to this forum thread (dated December 8th, 2004, 04:47 AM), was to go to network connections, view the properties of my Network card, and uninstall Client for MS networks, file & printer sharing, and uncheck TCP/IP. After that, I rebooted, reinstalled the services I uninstalled, and I was back in service. An easy fix, but a huge waste of time.

2007-03-28

 
I was stumbling around today and discovered this nifty list of XP commands. One of the commands listed is "magnify", which was new to me. Open the Run... prompt in XP, type it, and see what happens. Very handy tool, especially when looking closely at photos or scanned documents.

2006-12-15

 
There was a time when people found the square root of a number by hand using only pencil and paper (or chalk and slate). Here's a quick and fun web page on how to do it.

2006-10-24

 
Midterm Elections are upon us, and this Virginian will NOT be voting for George Allen. Besides doing a whole lot of nothing the past six years, Allen singled out a native Virginian of Indian descent in front of an audience and called him "macaca". I don't care how obscure the term is, you do NOT throw around racial slurs. Especially if you're a senator. And especially if the target of the slur is video taping you. And most especially if the target of the slur is video taping you on behalf of your opponent. Allen is not just a racist. He's a stupid racist. That's one of many reasons I'll be casting my vote for Jim Webb this election.

2006-07-11

 
Pfft...upgrade time. I upgraded my three-year old PostNuke installation at curiousmath.com to the latest stable release (0.762). Which meant I also needed to upgrade my forum. There's an evening of my life I'll never get back. On the whole, I was happy with the old versions and content to let them run indefinitely. But thanks to a security hole which spammers started exploiting, I had to upgrade to fix it. On the other hand, I have to say the upgrade itself went smoothly. It just took a while to get it all done. However, I performed another upgrade that did NOT go so smoothly: Ubuntu Linux. I tried upgrading to Dapper Drake 6.06 only to find out I couldn't complete the upgrade because of this known issue. To fix it required rebooting from CD, logging in as root, moving two offending files, and restarting the upgrade. Oh, sure it makes sense now. But for Linux NubeBoob here, it took a couple of days to figure out how to do it. So, on the offchance that anyone will ever read this in a quest for help, allow me to present the following two key pieces of information:

1. If you need to create a bootable linux CD-ROM, you need to actually burn an ISO image onto the CD. Don't just add the ISO file as a data file.
2. If you need to boot into Linux as root from a CD-ROM, type "linux single"

2006-06-02

 
This Rolling Stone article asks: Was the 2004 Election Stolen? Does a fat dog fart in the wind? Of course it was stolen. As the last polling stations closed on the West Coast, exit polls showed Kerry ahead in ten of eleven battleground states -- including commanding leads in Ohio and Florida -- and winning by a million and a half votes nationally. The exit polls even showed Kerry breathing down Bush's neck in supposed GOP strongholds Virginia and North Carolina. Against these numbers, the statistical likelihood of Bush winning was less than one in 450,000.

2006-05-28

 
The other day I noticed I had over 100 people currently visiting my math site. "Wow," I thought, "a couple of school classes must be looking at my site." The next day I noticed the same thing: over 100 people visiting the site. The day after that, again, triple digit visitors. Time to see what's going. So I ran a referral report and discovered Stumble Upon at the top of the list. After some investigation, I learned Stumble Upon was a toolbar extension for Firefox that allows you to randomly go to sites that other have rated favorably. I decided to give it a try and within moments was addicted. You click the "stumble" button and youíre taken to a web site that you likely would have never found on your own. (It helps that when you install the toolbar you get to indicated the type of topics you're interested in.) Likewise, when you find a site you like, you can click "I like it," making it a candidate for other stumblers to find. If you use Firefox, you should use Stumble Upon. Best Browser add-on ever.

2006-04-11

 
I am officially a Linux user. Over the weekend I successfully installed Ubuntu Linux along side Windows XP on my Dell XPS. And let me tell you, it could not have been easier. Thanks to these instructions on how to repartition your hard drive, I was able to complete the installation in about 90 minutes. The hardest part of was tracking down those instructions. The longest part was backing everything up to my external hard drive and then defragging my hard drive (before repartitioning). Once that was done, the actual Ubuntu installation took 20 minutes or so. If you've ever wanted to know what this Linux thing is about, you can't go wrong with Ubuntu. Not only is it slick and very cool, itís free. Order your free CDs and give it a go. They'll even send you a "Live" CD so you can boot Ubuntu from your CD-ROM and try it out without installing it.

2006-02-14

 
If it isn't enough I have my own website and blog (well, sort of), I had to go and sign up for a free Wiki at PBwiki. I couldn't resist. It was so easy to sign up for, I just had to give it a try. I'm glad I did. It's super simple to use and has wonderful potential for sharing information. If you've ever wondered that the heck a Wiki is and how to use it, here's your chance. I kind of envision my Wiki as a semi-personal place to jot down some thoughts, favorite sites, to-do lists, and what not. My wife is actually interested, too, now that I've showed her how easy it is to add content. So, anyway, I'm psyched! Now I have two sites to rarely update!

2006-02-12

 
Every now and then I get motivated to update my math web site in a major way. In 2003, I moved it over to PostNuke. In 2004, I added a phpBB bulletin board. This year I undertook the challenge of providing users the ability to use LaTeX to post math equations in the forum. I thought this would be extradorinarily difficult, but fortunately I was wrong. With the help of mimeTeX and LatexRender, I was able to make the necessary modifications to my forum in a matter of hours. And if I hadn't been such a dumb-ass, it would've been a matter of minutes. I spent almost all of my time trying to figure out why mimeTeX wouldn't work, when in the wee morning hours I realized I had installed the windows version on my unix web server. Yeah, um......that doesn't work.