similar to: Problems with pf() with certain noncentral values/degrees of freedom combinations

Hi everyone. I have a problem that I have been unable to determine either the best way to proceed and why the methods I'm trying to use sometimes fail. I'm using the pf() function in an optimization function to find a noncentrality parameter that leads to a specific value at a specified quantile. My goal is to have a general function that returns the noncentrality parameter that

Hello All, Has anyone written a function for the distribution function of a *doubly* non-central F-distribution? I looked through the archives, but didn't find anything. Thanks! Wolfgang

I sent a message a couple days ago about doing calculations for power of the ANOVA. Several people got back to me very quickly which I really appreciated. I'm working now on a similar problem, but instead of a balanced ANOVA, I have an unbalanced one. The first part of the question was: You assume that the within-population standard deviations all equal 9. You set the Type 1 error rate at á

hello R-friends, I'm looking for a quantile function for the noncentral f-distribution in the area of equivalence hypotheses testing. Can somebody help me? Many thanks ----------------------------------------------------------------- Dipl. Inform. J. Hedderich Institut f?r Medizinische Informatik Phone : 0431 / 5973182 und Statistik im Klinikum an der CAU

Dear List: The square of the noncentral t-statistic with noncentrality parameter \delta is a noncentral F with noncentrality parameter \lambda=\delta^2. So, t^2_{\nu,\delta} = F_{1,\nu,\lambda=\delta^2}. Consequently, it should follow that t^2_{1-\alpha/2,\nu,\delta} = f_{1-alpha,1,\vu,\lambda=\delta^2}. However, this is not what is happening with the following code. The central

Full_Name: Version: 1.9.0 OS: Windows XP Submission from: (NULL) (134.126.93.191) I believe the noncentrality parameter, lambda, in power.anova.test is incorrect. The noncentrality paramter is defined as lambda <- (groups - 1) * n * (between.var/within.var). The n should not be there. The function pf defines the noncentrality parameter as the sum of squares of the means. Therefore, the

This is just a suggestion/wish that it would be nice for the F-distribution functions to recognize limiting cases for infinite degrees of freedom, as the t-distribution functions already do. The t-distribution functions recognize that df=Inf is equivalent to the standard normal distribution: > pt(1,df=Inf) [1] 0.8413447 > pnorm(1) [1] 0.8413447 On the other hand, pf() will accept Inf

Full_Name: Long Qu Version: 2.3.1 OS: Windows XP Submission from: (NULL) (64.113.93.235) The QQ-plot of two versions of simulating noncentral F-distributed random numbers has quite different scales: > qqplot(rf(1000,2,15,3),qf(runif(1000),2,15,3)) The rf() function reads: > rf function (n, df1, df2, ncp = 0) { if (ncp == 0) .Internal(rf(n, df1, df2)) else rchisq(n, df1,

Hi All. I want to tweak a few minor things inside of internal C code. I have my Win. XP machine set-up to build packages (including C code), but I'm having problems getting the package to run correctly. In particular, I want to modify a few things inside of pnbeta.c (namely errmax and itrmax), which is what the pbeta() function calls upon when there is a noncentral parameter. I copied the

Hello I could not find whether there is any R-function that implements the inverse of a noncentral Beta. Could someone out there tell me where I can find it? Or how to implement it? Many thanks Ed [[alternative HTML version deleted]]

I have a data with 236 observations. After plotting the histogram, I found that it looks like non-central t distribution. I would like to get MLE for mu and df. I found an example to find MLE for gamma distribution from "fitting distributions with R": library(stats4) ## loading package stats4 ll<-function(lambda,alfa) {n<-200 x<-x.gam

Hi there: I'd thought these two versions of noncentral t-distribution are essentially the same: > qqplot(rt(1000,df=20,ncp=3),qt(runif(1000),df=20,ncp=3)) But, the scales of the x-axis and the y-axis are quite different according to the QQ-plot. Did I make any mistakes somewhere? Thanks, Long ---------------------------------

Hi, I have written out the log-likelihood function to fit some data I have (called ONES20) to the non-central chi-squared distribution. >library(stats4) >ll<-function(lambda,k){x<-ONES20; 25573*0.5*lambda-25573*log(2)-sum(-x/2)-log((x/lambda)^(0.25*k-0.5))-log(besselI(sqrt(lambda*x),0.5*k-1,expon.scaled=FALSE))} > est<-mle(minuslog=ll,start=list(lambda=0.05,k=0.006))

Hi, Actually I am facing a similar problem. I would like to fit both an ordinary (symmetric) and a non-central t distribution to my (one-dimensional) data (quite some values.. > 1 mio.). For the symmetric one, fitdistr or funInfoFun (using fitdistr) from the qAnalyst package should do the job, and for the non-central one.. am I right to use gamlss(x ~ 1, family=GT()) ? Anyway, I am a little

My apologies in advance if this is the wrong list to ask this in, but how well does pf work in 4.8-STABLE? And if so, what kernel options do I need to compile in? Can pf kernel options coexist w/ IPFW options, if I keep the IPFW modulus from loading? Can I still bridge in regular fashion w/ pf? I've already read up on http://pf4freebsd.love2party.net/install.html, but this seemd a bit

Bug Description: Problem with the function pf() when the non-centrality parameter is large. Here is a sample command. You should see a smooth line from 0 to about 55, and then the values of pf() go crazy from 55 to 100. ############################ ncp <- seq(0,100,length=200) plot(ncp,pf(5,7,2,ncp=ncp)) ############################ Version: platform = i686-pc-linux-gnu arch = i686 os =

Hello from ealier 6.0 there is problem with synproxy in pf filter: this one 6.1-PRERELEASE #2: Wed Mar 15 02:02:37 MSK 2006 pf.conf just with single rule pass in quick on lo0 proto tcp from any to any port 22 flags S/SA synproxy state result telnet 127.0.0.1 22 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. and it's hangs pfctl -s rules -v No ALTQ support in

Hi, I am trying to use SRIOV, usnig xen 4.0 on debian. On my dom0, xm pci-list-assignable-devices show that 0000:0f:10.0 0000:0f:10.2 0000:0f:10.4 0000:0f:10.6 0000:0f:11.2 0000:0f:11.4 0000:0f:11.6 these virtual interfaces correspond to eth2, i attach 0f:10.0 to a domU ubuntu machine, xm pci-attach ubuntu 0f:10.0 on my dom0 machine, i can ping other machine using eth2, (implying PF on eth2

Hi, I am trying to use SRIOV, usnig xen 4.0 on debian. On my dom0, xm pci-list-assignable-devices show that 0000:0f:10.0 0000:0f:10.2 0000:0f:10.4 0000:0f:10.6 0000:0f:11.2 0000:0f:11.4 0000:0f:11.6 these virtual interfaces correspond to eth2, i attach 0f:10.0 to a domU ubuntu machine, xm pci-attach ubuntu 0f:10.0 on my dom0 machine, i can ping other machine using eth2, (implying PF on eth2

Hello Everyone, I've been told that the memory allocation in R and S-Plus is different, with R being better at doing simulations for whatever reason(s). I was wondering if anyone could enlighten me on the differences in the memory usage/allocation (preferably in layman's terms!). The reason I ask this is because of a simulation I am trying to run. In it, I need to use the pt( )