search for: ncp

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 <<insert bug report here>> Reproduced on Debian and Windows ... On 2.4.x if you execute set.seed(12345) t.1 <- rt(n = 1000, df = 20) set.seed(12345) t.2 <- rt(n = 1000, df = 20, ncp = 0) all.equal(t.1, t.2) ## Not close to true This appears to be due to the fact that in 2.4.x rt is now rt function (n, df, ncp = 0) { if (missing(ncp)) .Internal(rt(n, df)) else rnorm(n, ncp)/sqrt(rchisq(n, df)/df) } <environment: namespace:stats> Whereas in 2.3....

help(qt) states that: "ncp non-centrality parameter delta; currently except for rt(), only for abs(ncp) <= 37.62" so I would expect that calling qt with non-centrality parameter exceeding 37.62 should fail, instead e.g. calling > mapply(function(x) qt(p = 0.9, df = 55, ncp = x),35:45) gives: [1] 40.21448 41....

Hello all, Here's my query: Running R 1.6.2 on FreeBSD 5.0, and on WinXP, and I find that the following hangs the process: dchisq(alpha=0.01, df=1, ncp=295) but it does work for ncp < 294.92. Is this general? Best wishes to all, Andrew Andrew Robinson Ph: 208 885 7115 Department of Forest Resources Fa: 208 885 6226 University of Idaho E : andrewr at uidaho.edu PO Box 441133 W : http://www.uidaho.edu/~andrewr Moscow...

The function 'pchisq' from the 'stats' library gives a wrong result if the argument equals exactly zero: # Upper tail of central 1-df chi^2 distribution > pchisq(1 , 1, ncp=0, lower.tail = F, log.p = FALSE) [1] 0.3173105 > pchisq(0.5 , 1, ncp=0, lower.tail = F, log.p = FALSE) [1] 0.4795001 > pchisq(0.01 , 1, ncp=0, lower.tail = F, log.p = FALSE) [1] 0.9203443 > pchisq(0.0001 , 1, ncp=0, lower.tail = F, log.p = FALSE) [1] 0.9920213 > pchisq(0....

...General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. * * * NOTE * * Requires the following auxiliary routines: * * lgammafn(x) - log gamma function * pnt(x, df, ncp) - the distribution function for the non-central t distribution * * * DESCRIPTION * * The non-central t density is * * f(x, df, ncp) = df^(df/2)*exp(-.5*ncp^2)/(sqrt(pi)*gamma(df/2)*(df+x^2)^((df+1)/2))*sum_{k=0}^Infinity gamma((df + k + df)/2)*ncp^k/prod(1:k)*(2*x^2/(df+x^2))^...

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 = linux-gnu system = i686, linux-gnu status = major = 1 minor = 1.1 year = 2000 month = August day = 15 language = R Search Path: .GlobalEnv, Auto...

Hi Folks, I note that, while the "chisq" functions dchisq(x, df, ncp=0, log = FALSE) pchisq(q, df, ncp=0, lower.tail = TRUE, log.p = FALSE) qchisq(p, df, ncp=0, lower.tail = TRUE, log.p = FALSE) rchisq(n, df, ncp=0) all have a slot for the non-centrality parameter "ncp", of the functions for the t and F distributions: dt(x, df, log =...

Full_Name: Jerry W. Lewis Version: 2.6.1 OS: Windows XP Professional Submission from: (NULL) (24.147.191.250) pchisq(0,0,ncp=lambda) returns 0 instead of exp(-lambda/2) pchisq(x,0,ncp=lambda) returns NaN instead of exp(-lambda/2)*(1 + SUM_{r=0}^infty ((lambda/2)^r / r!) pchisq(x, df + 2r)) qchisq(.7,0,ncp=1) returns 1.712252 instead of 0.701297103 qchisq(exp(-1/2),0,ncp=1) returns 1.238938 instead of 0

Hi Folks, I'm looking for a neat procedure for the following: Given t0 such that pt(t0,df,ncp=0) = alpha (given) find ncp0 such that for given beta pt(t0,df,ncp=ncp0) = (1 - beta) (In other words, what's the ncp such that you get power (1-beta) to detect it, using a 1-sided test with size alpha when ncp = 0?) In the past I've done the groping by hand, but this time it needs to...

...ta} = f_{1-alpha,1,\vu,\lambda=\delta^2}. However, this is not what is happening with the following code. The central distributions agree as they should but the noncentral distributions do not. Am I missing something or is there a bug in the code? > alpha <- 0.05 > nu <- 10 > NCP <- c(0,1,2,3) > TV <- (qt(1-alpha/2,nu,NCP))^2 > FV <- qf(1-alpha,1,nu,NCP^2) > rbind(TV,FV) [,1] [,2] [,3] [,4] TV 4.964603 12.535179 24.58013 41.71937 FV 4.964603 9.285829 18.98771 32.97855 > TV <- (qt(1-alpha/2,nu,NCP))^2 > FV <- qf(1-alpha/2,1...

Dear all, I want to see the source codes for "dchisq(x, df, ncp=0, log = FALSE)", but cannot find it. I input "dchisq" in the R interface, and then enter, the following message return: > dchisq /*****************************************************/ function (x, df, ncp = 0, log = FALSE) { if (missing(ncp)) .Internal(dchisq(x, df,...

?pt states that ncp=0 is default, so this is correct > pt(3,3) [1] 0.9711656 > pt(3,3, ncp=0) [1] 0.9711656 but this is not > pt(-Inf,3) [1] 0 > pt(-Inf,3,ncp=0) [1] 0.5 is it? Torsten --please do not edit the information below-- Version: platform = i686-pc-linux-gnu arch = i686 os = linux-gnu s...

...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, ncp = ncp)/rchisq(n, df2) } <environment: namespace:stats> where I believe both the numerator and the denominator should be divided by their corresponding degrees of freedom. My suggested (slighly augmen...

Has any advancement been made to get 3102 operational in either a SIP or H323 asterisk environment. A post back in time mentioned a downloader service. >From the posts and articles I have read, the NCP is acting like a bootp and tftp server which uploads the configuration to the phone?? Am I close? if so, where does one get the SIP image for he 3102 and 2102 phones? I had 8 donated, but they are useless without a NBX or NCP ? Any specs on how to configure linux to act like one? Thanks in adva...

Full_Name: David Clayton Version: 1.8.1 OS: Linux Submission from: (NULL) (131.111.126.242) qchisq behaves very strangely when ncp is passed as zero (forcing internal qnchisq to be called) when first argument is small. Eg > qchisq(1-1e-6, 1, ncp=0, lower.tail=TRUE) qchisq(1-1e-6, 1, ncp=0, lower.tail=TRUE) [1] 1024 while, if ncp is unspecified, > qchisq(1-1e-6, 1) qchisq(1-1e-6, 1) [1] 23.92813

Full_Name: Richard Mott Version: 1.9.0 OS: Windows XP Submission from: (NULL) (81.178.233.208) Shouldn't these give the same answer? > pchisq(67.60644,df=1,lower.tail=F,ncp=0) [1] 3.219647e-15 > pchisq(67.60644,df=1,lower.tail=F) [1] 1.996145e-16 >

...e same number. Am I doing something wrong in the calculation of the power? Here's my code: T<-5 R<-5 sigmasq<-0.1 q<-10 Vl<-(T*R)-2 Dl<-(R*(T-1)*T*(T+1)/(12*sigmasq))*(log(1+(q/100)))^2 #Dl result is still similar power.1<-1-pf(qf(.95,(T*R-2),1,ncp=0),(T*R-2),1,ncp=Dl) Thank you for any suggestions/help. I'm using R2.4.1, on windowsXP. Erik Meesters [[alternative HTML version deleted]]

...ion" *** caught segfault *** address 0x7fffeff7ffe30, cause 'memory not mapped' Traceback: 1: foo() 2: foo() 3: foo() ... 2154: foo() 2155: foo() 2156: foo() aborting ... Second error was in d-p-q-r-tests.Rout from this test: ## dbeta(*, ncp): a <- rlnorm(100) stopifnot(All.eq(a, dbeta(0, 1, a, ncp=0)), dbeta(0, 0.9, 2.2, ncp = c(0, a)) == Inf ) ## the first gave 0, the 2nd NaN in R <= 2.3.0 and generated this output in d-p-q-r-tests.Rout.fail > > ## dbeta(*, ncp): > a <-...

Full_Name: Drouilhet R?my Version: 1.8.1 OS: Linux Submission from: (NULL) (195.221.43.136) qchisq(1,10) works well but qchisq(1,10,ncp=0) does not work whereas ncp=0 is the default value of the function qchisq(1,10). (of course, 10 will be replaced by any integer value). Let us notice that this bug occurs only when applying probability one. (qchisq(seq(0,.9,.1),10,ncp=0) works very well).

I was wondering how do I actually see what's inside a function, say, density of t distribution, dt()? I know for some, I can type the function name inside R and the code will be displayed. But for dt(), I get > dt function (x, df, ncp, log = FALSE) { if (missing(ncp)) .Internal(dt(x, df, log)) else .Internal(dnt(x, df, ncp, log)) } <environment: namespace:stats> I am curious because I am doing rejection sampling and want to find a "bigger" distribution. [[alternative HTML version deleted]]