tephanie asked in 511 today if we were able to get the random seed which was set by set.seed() but we were only given the random numbers (without knowing the seed). This kind of “hacker” questions sound interesting. One dirty solution should be the brute-force method, e.g: # x: the random vector; # FUN: the
169 search results for "PCA"
A quicky..
If you’re (and you should) interested in principal components then take a good look at this. The linked post will take you by hand to do everything from scratch. If you’re not in the mood then the dollowing R functions will help you. An example. # Generates sample matrix of five discrete clusters that have
Press Enter in LyX Sweave as You Wish
or a long time I’ve been wondering why we are not able to use Enter in the LyX Scrap environment which was set up by Gregor Gorjanc for Sweave. Two weeks ago, I (finally!) could not help asking Gregor about this issue, as I’m using “LyX + Sweave” more and more in my daily work.
Updated Tactical Asset Allocation Results
In November, I used the strategy in Mebane Faber's Tactical Asset Allocation paper to provide an introduction to blotter. Faber has updated the strategy's results through the end of 2009. For those interested, he expands on the paper in his book, The...
A tale of two visualizations (because it’s Friday)
GEEK FIGHT!!! says JD Long on Twitter as the New York Times publishes a widely-reposted interactive graphic about Netflix rental data, and the Wall Street Journal also gets into the interactive-viz game with a graphic on bank bonuses. If it's a fight, it's a knockout in the first round, if you ask me. There's no surprise why the Netflix...
Create Animations in PDF Documents Using R
ince animation 1.0-9, we will be able to create a PDF document with an animation embedded in it; the function is saveLatex(), and its usage is similar to saveMovie() and saveSWF(): you pass an R expression for creating animations to this function, and this expression will be evaluated in the function; the image frames get
50000 Revisions Committed to R
oday Romain Francois posted an interesting topic in the R-help list, and you can read his blog post for more details: celebrating R commit #50000. 50000 is certainly not a small number; we do owe R core members a big “thank you” for their great efforts in this fantastic statistical language in the 13 years.
How to Import MS Excel Data into R
s Sir Francis Bacon said, “Histories make men wise; poets witty; the mathematics subtile; natural philosophy deep; moral grave; logic and rhetoric able to contend.” And Windows stupid. He should have added the last sentence if he were a Windows user in this age. 1. Avoid Using M$ Excel A lot of R users often ask this question:
Formatting Decimals in Texts with R
anping Chen raised a question in the Chinese COS forum on the output of Eviews: how to (re)format the decimal coefficients in equations as text output? For example, we want to round the numbers in CC = 16.5547557654 + 0.0173022117998*PP + 0.216234040485 * PP(-1) + 0.810182697599 * (WP + WG) to the 3rd decimal places.
Counterintuitive Results in Flipping Coins
oin-flipping is a rather old topic in probability theory, so most of us think we know very well about it, however, the other day I saw a question about this old topic (in David Smith’s REvolution?) which was beyond me expectation: how many times do we need to flip the coin until we get a
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
