Displaying 20 results from an estimated 4000 matches similar to: "Density of non-central t distribution"
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)
2017 Jun 22
1
Compiling R-devel - missing some expected features (zlib, bzlib, lzma, PCRE)
Hi All,
I am compiling R-devel on Linux (Ubuntu 16.04.2) and that works just fine, but I am missing some of the expected features, as shown here:
https://cran.r-project.org/doc/manuals/r-devel/R-admin.html#Linux
In particular, after configure (using all defaults), I see:
R is now configured for x86_64-pc-linux-gnu
[...]
Interfaces supported: X11
External libraries:
2020 May 05
1
Use of MathJax (or something similar) in .Rd files
Hi All,
After some tinkering, and with support from Duncan, I put together a package that allows for easy inclusion of MathJax equations in Rd files. The package has been submitted to CRAN, but those who want to try this out already can get it here:
https://github.com/wviechtb/mathjaxr
or in other words:
install.packages("remotes")
2003 Jul 16
2
Density function for non-central t distribution
Hi,
I've written some C code for density evaluation of the non-central t distribution. It works
with the R-1.7.1 source code if placed in the src/nmath directory and after appropriate
changes are made to Makefiles, to the dt function in src/library/base/R/distn.R etc.
I haven't read a lot of R source code so it may need some R-ification, but I've tried to use the
dt.c file as a
2020 Apr 30
2
Use of MathJax (or something similar) in .Rd files
Thanks Gabor and Duncan! It works. For those interested, I added this to the beginning of the \details{} section:
\if{html}{\out{
<script id="MathJax-script" async
src="https://cdn.jsdelivr.net/npm/mathjax at 3/es5/tex-mml-chtml.js">
</script>
}}
And then I can use:
\if{html}{\out{\(B_{x(a,b)} = \int_0^x t^{a-1} (1-t)^{b-1} dt\)}}
or
2020 Jun 21
1
Possible bug in heatmap()?
Dear All,
There might be a bug in heatmap():
x <- matrix(rnorm(10*5), 10, 5)
heatmap(x, labCol=1:5)
Error in axis(1, 1L:nc, labels = labCol, las = 2, line = -0.5, tick = 0, :
'at' and 'labels' lengths differ, 5 != 10
Works fine under 4.0.1. Looking at the code from 4.0.1 vs. Rdevel, esp. this part sticks out:
labRow <- labRow[rowInd] %||% rownames(x) %||%
2008 Aug 27
5
Integrate a 1-variable function with 1 parameter (Jose L. Romero)
Hey fellas:
I would like to integrate the following function:
integrand <- function (x,t) {
exp(-2*t)*(2*t)^x/(10*factorial(x))
}
with respect to the t variable, from 0 to 10.
The variable x here works as a parameter: I would like to integrate the said function for each value of x in 0,1,..,44.
I have tried Vectorize to no avail.
Thanks in advance,
jose romero
2003 Feb 02
3
Finding Missing Data Patterns
Dear R-Helpers,
I have a large data matrix, which contains missing data. The matrix
looks something like this:
1) X X X X X X NA NA NA
2) NA NA NA NA X X X X X
3) NA NA X X X X NA NA NA
4) X X X X X X X X X
5) X X NA NA X NA NA NA NA
and so on. Notice that the first row starts with complete data but ends
with missing. The second row starts with missing, but the rest is
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
2002 Aug 09
2
Help with improving efficiency
Dear All,
I have a problem that I think could be solved much more efficiently, but
I don't have a clue how to accomplish this. I have a matrix W with
dimensions k*(p+1):
Let's say W is 5*4 and looks like this:
> W
[,1] [,2] [,3] [,4]
[1,] 1 -1 -1 1
[2,] 1 1 1 1
[3,] 1 2 -2 -1
[4,] 1 0 -1 -1
[5,] 1 -2 -1 0
I want to take
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 Mar 08
2
Looking for non-central F quantile
Greetings all,
I'm trying to figure out how to calculate the inverse CDF (i.e. a
quantile) for a non-central F distribution. I could put together a quick
numerical solver routine using the CDF, but I wonder if there's a function
that I've missed that would be more efficient?
Thank-you,
Andrew
Andrew Robinson Ph: 208 885 7115
Department of Forest Resources Fa: 208 885
2000 Jul 13
2
R_memory/Question
Bonjour,
Je voudrais savoir comment on peut modifier les capacit?s de m?moire pour le logiciel R, car j'ai un probl?me pour lire un tableau contenant 200000 observations et 30 variables.
Je vous remercie d'avance pour toute aide ?ventuelle.
Cordialement,
Steffy.Ruiz at wanadoo.fr
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2024 Jun 23
1
Issue with pkgconf when upgrading to 4.4.1
Hi all,
I am running Ubuntu 20.04.6 (focal) (yes, planning to upgrade soon) and just updated to 4.4.1. However, the process did not quite go as smoothly. 'sudo apt upgrade' ran but 'r-base-dev' was not updated because of a dependency issue:
[08:57] ? wviechtb at wv-x5 ? ~/ ? sudo apt upgrade r-base-dev
Reading package lists... Done
Building dependency tree
Reading state
2012 Jan 17
4
Problema para integrar una funcion ajustada a un conjunto de datos con la instruccion sm.density(x)
Estimada comunidad, nuevamente con algo que no se como hacer en R, pero
aprendiendo ....
El problema es el siguiente:
1. tengo un conjunto de 10 mil datos (n) cuyo valor va entre 0 y 10.000 a
los que aplico una funcion sm.density() para obtener una especie de
histograma pero con una curva que parece continua.
2. Una vez que obtengo esa curva necesito calcular el area bajo la curva en
ciertos
2002 May 28
4
Indexing Elements of a Dataframe
Hello List-Members,
Let's say that I have the following code:
for (i in c(10, 20, 30)) {
for (j in c(200, 400, 600)) {
...
...
x <- "something"
* (code here)
}
}
* Now, x is some result that I want to put into a results "matrix" that
looks like this:
200 400 600
10
20
30
I came up with an ad-hoc solution adding some counters (called
2001 Nov 27
3
Equations as arguments to functions
I am trying to pass an equation as an arguement to a function, which seems
pretty straightforward given lazy evaluation.
I constructed the following little test to make sure I sort of knew what I
was doing:
go <- function(X,eq) { C <<- X*2; d <<- eq}
a _ rnorm(100)
go(10,eq=a[.5*length(a)]+C+1)
> C
[1] 20
> d
[1] 21.10551
> a[.5*length(a)]
[1] 0.1055086
Everything
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 =
2006 Aug 26
1
Capture of iterative integration output
Hello,
I am a novice R user and am having difficulty retrieving the values
from 21 iterations of the R function integrate.
The only way I have found is to do a write.table and then a read.table
as shown in the code below. I would rather capture the 21 values inside
the braces ( sapply might work, but I can't set it up without getting an
error in function) so I could compute the
2005 Dec 30
8
WxRuby newbie Mac OS 10.4 install questions
Hi. Forgive me if I am asking questions that have already been
answered a million times,
but there doesn''t seem to be an easy way to search the wxruby-users
archives, so...
I tried to install wxruby for the Mac
by downloading the latest Mac package installer from
rubyforge.org/frs/download.php/1985/wxruby-0.6.0-osx-panther.dmg
and tried to run some of the wxruby-0.6.0/samples from the