On 10/11/07, Douglas Bates <[EMAIL PROTECTED]> wrote: > On 10/11/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > > Dear list, first accept my apologies for asking a non-R question. > > > Can anyone point me to a good reference on logistic regression? web or > > book references would be great. I am interested in the use and > > interpretation of dummy variables and prediction models. > > I checked the contributed section in the CRAN homepage but could not > > find anything (Julian Faraway´s "practical Regression and ANOVA using > > R" does not cover logistic regression) > > The wikipedia article on logistic regression > (http://en.wikipedia.org/wiki/Logistic_regression) contains a brief > description and some references. Statisticians often consider > logistic regression to be an example of a more general class of models > called generalized linear models, which is why the R function to fit a > logistic regression model is called glm. There is a link in the > logistic regression wikipedia article to the generalized linear model > article. > > Whenever you use wikipedia you should be cautious of the quality of > the information in the articles. Generally the articles are good as a > brief introduction but they can and do contain errors so you should > check important facts and not take them at face value. A person in > one of my classes asked about the standard deviation and I suggested > that they look at the wikipedia article on the topic. Then I looked > at it myself and saw that one of the things mentioned is that the > standard deviation of the Cauchy distribution is undefined, which is > true, but the reason given is because E[X] is undefined, which is not > true.
As several people have pointed out to me privately, I'm the one spreading misinformation, not the authors of the wikipedia article. My, apparently faulty, recollection was that E[X] was defined (because the density is symmetric) but E[X^2] was not defined. It looks like I need to review some elementary properties of distributions and integrals. Note to self: Don't respond to mailing list postings until fully caffinated. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
