similar to: Density function for non-central t distribution

Displaying 20 results from an estimated 1000 matches similar to: "Density function for non-central t distribution"

2003 Sep 03
0
Updated power.t.test
Greetings, I've tried to update the power.t.test function to allow for different sample sizes and sample variances in the case of a two-sample t test. I'd gladly update the corresponding help page if the code is to replace the current power.t.test function. The modified power.t.test code is included below. The changes are as follows: - Added three new arguments to the function *
2003 Jul 24
0
nls.control in gnls
Hi, I've made a selfStart function for use with gnls and the following piece of code works nicely: check1 <- gnls(y ~ spot.shape.fct(xcord, ycord, background, spotintensity, rho, sigma, delta, mux, muy), start=getInitial(y ~ spot.shape.fct(xcord, ycord, background, spotintensity, rho,
2004 Feb 10
6
R: lags
hi all how does one simulate a random walk process? i.e y(0)=0 y(t)=y(t-1)+ e(t) where e(t) is normal(0,1) say. Regards allan
2000 Nov 28
1
non-centrality parameter in pf() (PR#752)
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 =
2008 Jun 14
1
qt with ncp>37.62
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 41.35293 42.49164 43.68862 44.82945 45.97048 47.11170 48.25310 [9]
2002 Oct 17
3
Non-central distributions
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 = FALSE)
2014 Dec 15
1
Making iconv portable?
On Dec 15, 2014, at 1:37 PM, Spencer Graves <spencer.graves at prodsyse.com> wrote: > > >> On Dec 15, 2014, at 10:13 AM, Simon Urbanek <simon.urbanek at r-project.org> wrote: >> >>> >>> On Dec 15, 2014, at 12:21 PM, Kurt Hornik <Kurt.Hornik at wu.ac.at> wrote: >>> >>>>>>>> Spencer Graves writes:
2012 Feb 11
2
How to see a R function's code
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
2001 May 18
1
Non-Central t
In the help file for the non-central t, the following appears: ncp: non-centrality parameter delta; currently `ncp <= 37.62'. I assume that this means the ncp cannot exceed 37.62. Is this still the case and is there any plans to increase this restriction? Thanks! Jeff Jeff Morris Design Support Clinical Chemistry R&D Ortho-Clinical Diagnostics email: jmorris6 at ocdus.jnj.com
2003 Apr 13
2
Peculiarity in non-central qchisq for ncp > 294.92 ...
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
2014 Dec 15
0
Making iconv portable?
> On Dec 15, 2014, at 10:13 AM, Simon Urbanek <simon.urbanek at r-project.org> wrote: > >> >> On Dec 15, 2014, at 12:21 PM, Kurt Hornik <Kurt.Hornik at wu.ac.at> wrote: >> >>>>>>> Spencer Graves writes: >> >>> Hello, All: >>> What would it take to make ?iconv? portable? >> >> >>> I
2007 Sep 03
0
buglet?? in nlme:::corRatio documentation
[hoping to redeem myself for my last spurious bug report] From ?corRatio: Letting d denote the range and n denote the nugget effect, the correlation between two observations a distance r apart is (r/d)^2/(1+(r/d)^2) when no nugget effect is present and (1-n)*(r/d)^2/(1+(r/d)^2) when a nugget effect is assumed. This disagrees with the C code (corStruct.c) /* Rational class
2002 Aug 24
2
Density of non-central t distribution
Hello Everybody, Is there a function available for calculating the density of a non-central t distribution? (dt does not accept the ncp option). Thanks in advance! -- Wolfgang Viechtbauer "Are you not thinking what I am not thinking?" -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read
2003 May 08
1
nls, restrict parameter values
Hi, I posted a question (bellow) a few weeks ago and had a reply (thanks Christian) that partly solves the problem, but I still would like to be able to restrict some of the independent variables in a nls model to be always >0, (is there a way to do it)?? Thanks, Angel >From: "Christian Ritz" <ritz at dina.kvl.dk> >To: "Angel -" <angel_lul at
2003 Jan 15
2
Bug or Feature? LogLik.nls and non-central F distribution.
I have a dataset that I am running non-linear regression on via the following code: Hill <- function(E0,Em,C50,g,C){ # # Hill is the hill interaction function. # # E0 Represents the minimum interaction Effect # # Em Represents the Maximum Interaction Effect # # C50 represents the concentration at which 50% of the effect occurs. # # gamma represents the cooperativity of the
2010 Aug 27
3
[PATCH 0 of 3] libxl: cleanups for type destructor generation
Following series cleans up a few niggles in the libxl destructor autogeneration. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
2000 Dec 14
2
Accuracy problem in dchisq for non-central chi-squared
Hi, I think I have identified a inaccuracy in dchisq when the non-centrality parameter is non-zero and large. Here's a little test: sys.dchisq.test <- function(N = 100000,mean = 0) { z <- rnorm(N,mean = mean, sd = 1) x <- z^2 xmin <- min(x) xmax <- max(x) br <- seq(xmin,xmax,length = 101) dbr <- br[2]-br[1] hist(x,br) p <- dchisq(br,df = 1,ncp =
2005 Aug 18
3
Console
I am at my first steps with R... and I already notice that the console has a quite limited number of lines. Can anyone tell me how to visualise all the information, which is actually present? I only see the last part of the output, which obviosly exceeds the maximum number of rows in the console. Thank you very much for your help! Daniela [[alternative HTML version deleted]]
2014 Dec 15
2
Making iconv portable?
> On Dec 15, 2014, at 12:21 PM, Kurt Hornik <Kurt.Hornik at wu.ac.at> wrote: > >>>>>> Spencer Graves writes: > >> Hello, All: >> What would it take to make ?iconv? portable? > > >> I ask, because I want to convert accented characters to >> vanilla ASCII, thereby converting, e.g., ?Ra?l? to ?Raul?, and >> Milan
2001 Feb 09
0
Re: [Rd] dnbinom(,size<1,)=0 (PR#842)
my current code for dnbinom.c has prob = dbinom_raw(n,x+n,p,1-p,give_log); f = ((double)n)/((double)(n+x)); return((give_log) ? log(f) + prob : f*prob); which should work for x>=0, n>=0, 0<=p<=1. dbinom.raw(x,n,p) is intended to work for x>=0, n>=0, 0<=p<=1, without integer checks. When necessary (ie. for x in the dnbinom case) the checks should be done in the