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Dear List Members, I have encountered two problems when using the step function to select models. To better illustrate the problems, an R image (step.add1.test.RData) which includes the objects needed to run the code (step.add1.test.R) can be found at www.biostat.wisc.edu/~pwang/r-help/<http://www.biostat.wisc.edu/%7Epwang/r-help/> lm.data.frame have factor variables with 3 levels. The following run shows the first problem. AICs (* and **) are different. I noticed that the Df for rs13482096:rs13483699 is 4, while I think Df should be 6, 2 from rs13483699 and 4 from...

Hi, I have 2 dataset, plot(data1) plot(data2), but it comes as two graphs, can I draw both on a single panel so I can compare them? Thanks Pat

Hi, My R version is 2.4.1 and I installed the the packages MASS and run command library("MASS"), however when I type ?rmvnorm, no help topic found, it worked before. I tried to ype ?rinvgamma from "MCMCpack" which works great. Anybody have idea? I also reinstalled MASS package, but when I try to type rmvnorm(), no functions found. Pat

CRAN (and crantastic) updates this week New packages ------------ * disclapmix (0.1) Maintainer: Mikkel Meyer Andersen Author(s): Mikkel Meyer Andersen and Poul Svante Eriksen License: GPL-2 http://crantastic.org/packages/disclapmix disclapmix makes inference in a mixture of Discrete Laplace distributions using the EM algorithm. * EstSimPDMP (1.1) Maintainer: Unknown Author(s):

Hi, I wrote a simple derivative program (ftest=deriv(y~x^2, c("x"), function(x){} )) I put (ftest=deriv(y~x^2, c("x"), function(x){} ))(1) which return 2 which is correct. however, if I want the output to be 0 and hopefully a new inverse function can take in output (2) and return x=1. Can this be accomplished. Maybe output(0) can return x=0 Thanks pat

Hi, All: assume I need to generate X from inverse gamma with parameter (k, beta). should I generate from Y from gamma(-k, beta), then take X=1/Y? Thanks pat

Hi, The silverman's paper introduction offer how to find a mode for one dimensional data based on software http://www.stanford.edu/~kasparr/software/silverman.r, for two dimensional data I use kde2d to smooth it out first, then I get a matrix of densities for all the X(one dimension) cross Y(another dimension). I sort X and Y first before I pass the values to kde2d(x, y, c(hx, hy)), the

Hi, Does anyone know how to count the number of modes in 2 dimensions using kde2d function? Thanks Pat

Hi, I have a vector contains values 1,2,3. Can I call a function split to split it into 3 vectors with 1 corresponds to value ==1, which contain all the indexes for value==1. 2 corresponds to value ==2 which contain all the indexes for value=2 Thanks pat

Dear List Members, I have encountered two problems when using the step function to select models. To better illustrate the problems, attached is an R image which includes the objects needed to run the code attached. lm.data.frame have factor variables with 3 levels. The following run shows the first problem. AICs (* and **) are different. I noticed that the Df for rs13482096:rs13483699 is 4,