Displaying 20 results from an estimated 200 matches similar to: "number of required trials"
1997 Jul 09
1
R-beta: Problem with `rpois'
There is a problem with `rpois'. It does seem to take care about the
order of the arguments. This is an example:
> rpois(n=1,lambda=2)
[1] 3
> rpois(lambda=2,n=1)
[1] 2 0
It obviously uses the first argument as the number of samples to be
drawn, which is wrong.
I used Version 0.49 Beta (April 23, 1997).
Fredrik
1997 Jul 09
1
R-beta: Problem with `rpois'
There is a problem with `rpois'. It does seem to take care about the
order of the arguments. This is an example:
> rpois(n=1,lambda=2)
[1] 3
> rpois(lambda=2,n=1)
[1] 2 0
It obviously uses the first argument as the number of samples to be
drawn, which is wrong.
I used Version 0.49 Beta (April 23, 1997).
Fredrik
2020 Aug 10
2
qnbinom with small size is slow
Thanks Ben for verifying the issue. It is always reassuring to hear
when others can reproduce the problem.
I wrote a small patch that fixes the issue
(https://github.com/r-devel/r-svn/pull/11):
diff --git a/src/nmath/qnbinom.c b/src/nmath/qnbinom.c
index b313ce56b2..d2e8d98759 100644
--- a/src/nmath/qnbinom.c
+++ b/src/nmath/qnbinom.c
@@ -104,6 +104,7 @@ double qnbinom(double p, double size,
2020 Aug 21
1
qnbinom with small size is slow
Hi Martin,
thanks for verifying. I agree that the Cornish-Fisher seems to struggle
with the small size parameters, but I also don't have a good idea how to
replace it.
But I think fixing do_search() is possible:
I think the problem is that when searching to the left y is decremented
only if `pnbinom(y - incr, n, pr, /*l._t.*/TRUE, /*log_p*/FALSE)) < p` is
FALSE. I think the solution is
2020 Aug 20
0
qnbinom with small size is slow
>>>>> Constantin Ahlmann-Eltze via R-devel
>>>>> on Mon, 10 Aug 2020 10:05:36 +0200 writes:
> Thanks Ben for verifying the issue. It is always reassuring to hear
> when others can reproduce the problem.
> I wrote a small patch that fixes the issue
> (https://github.com/r-devel/r-svn/pull/11):
> diff --git
2020 Aug 07
2
qnbinom with small size is slow
Hi all,
I recently noticed that `qnbinom()` can take a long time to calculate
a result if the `size` argument is very small.
For example
qnbinom(0.5, mu = 3, size = 1e-10)
takes ~30 seconds on my computer.
I used gdb to step through the qnbinom.c implementation and noticed
that in line 106
(https://github.com/wch/r-source/blob/f8d4d7d48051860cc695b99db9be9cf439aee743/src/nmath/qnbinom.c#L106)
2008 Aug 21
1
pnmath compilation failure; dylib issue?
(1) ...need to speed up a monte-carlo sampling...any suggestions about
how I can get R to use all 8 cores of a mac pro would be most useful
and very appreciated...
(2) spent the last few hours trying to get pnmath to compile under os-
x 10.5.4...
using gcc version 4.2.1 (Apple Inc. build 5553) as downloaded from
CRAN, xcode 3.0...
...xcode 3.1 installed over top of above after
2001 Feb 08
2
dnbinom(,size<1,)=0 (PR#842)
This came up on r-help but indicates a bug.
dnbinom(x,n,p) calls dbinom_raw(n-1,...)
which returns 0 for n<1.
-thomas
---------- Forwarded message ----------
Date: Thu, 08 Feb 2001 17:10:23 +0000
From: Yudi Pawitan <yudi@stat.ucc.ie>
To: Mark Myatt <mark@myatt.demon.co.uk>
Cc: R-Help <r-help@stat.math.ethz.ch>
Subject: Re: [R] Goodness of fit to Poisson / NegBinomial
2020 Aug 07
0
qnbinom with small size is slow
?? I can reproduce this on
R Under development (unstable) (2020-07-24 r78910)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Pop!_OS 18.04 LTS
? In my opinion this is worth reporting, but discussing it here first
was a good idea.? Many more people read this list than watch the bug
tracker, so it will get more attention here; once the excitement has
died down here (which might be
2001 Feb 07
3
Goodness of fit to Poisson / NegBinomial
All,
I have some data on parasites on apple leaves and want to do a
goodness of fit test to a Poisson distribution. This seems to
do it:
mites <- c(rep(0,70),
rep(1,38),
rep(2,17),
rep(3,10),
rep(4,9),
rep(5,3),
rep(6,2),
rep(7,1))
tab <- table(mites)
NSU <- length(mites)
N <-
2009 Mar 17
3
R does not compile any more on FreeBSD 8.0-CURRENT
On a recent FreeBSD 8.0-CURRENT (i386) building R (any version) breaks
with the following messages:
----------------------------------------------------------------------
[...snip...]
gcc -std=gnu99 -I. -I../../src/include -I../../src/include
-I/usr/local/include -DHAVE_CONFIG_H -g -O2 -c wilcox.c -o wilcox.o
gcc -std=gnu99 -I. -I../../src/include -I../../src/include
-I/usr/local/include
1997 Dec 13
1
R-beta: Compile error; R-0.60.1, Solaris 2.6, gcc 2.7.2.1
Hi!
I have just downloaded the R-0.60.1 sources and have problems compiling R
on a Sun Ultra 1 running Solaris 2.6 and gcc 2.7.2.1.
I have not been able to find to find any compiling hints in the
documentation or the FAQ.
After ./configure I use make and get the output below.
Any hints are welcome.
I am not on the list, so please answer me directly too.
Best regards
Jens
---
Jens Lund
2009 Oct 26
1
GLMMPQL and negbinomial: trouble with the X-axis in PREDICT
I'm having some difficulty with graphing outputs of a GLM model I've
been working. I have count data for both my predictor (only 1) and
response variables, and I have pseudoreplication which I've modeled as
a random effect. The odTest() from pscl:: indicated that the negative
binomial distribution fit better than Poisson, and I then proceeded by
estimating theta from glm.nb.
My
2005 Jan 05
3
strange behaviour of negative binomial
Dear list,
I ran into a strange behaviour of the pnbinom function - or maybe I
just made a stupid mistake.
First thing is that pnbinom seems to be very slow. The other - more
interesting one - is that I get two different curves when I plot the
estimated density and the density given by pnbinom. Shouldn't it be the
same?
This is only the case, I think, if I use the parameter size = 1. I
2008 Apr 17
2
pnbinom.c qnorm.c
Dear R users,
I was wondering from where I could get the C source code to compute
pnbinom() and qnorm() ?
(I would use R in batch mode but I find the startup time prohibitive, unless
there is a way to speed it up)
I searched the Web and it clearly is part of the R distribution, I just
don't know how to extract them.
Thanking you !
Markus Loecher
Princeton, NJ
[[alternative HTML version
1999 May 03
1
problems compiling R-0.63.3 on alpha
Hi again !
Thanks for the info on updating the config.site file which I
have done. I have also added -lm in the Makeconf manually
because this is needed explicitly for DEC cc.
However, there are still a few problems when linking some
of the files as you can see from the enclosed log.
Ciao,
Andreas
-------------------------------------------------------
R-0.63.3>make
make[1]: Entering
2008 Feb 10
1
Error while using fitdistr() function or goodfit() function
Try changing your method to "ML" and try again. I tried the run the
first example from the documentation and it failed with the same error.
Changing the estimation method to ML worked.
@List: Can anyone else verify the error I got? I literally ran the
following two lines interactively from the example for goodfit:
dummy <- rnbinom(200, size = 1.5, prob = 0.8)
gf <- goodfit(dummy,
2010 Feb 19
1
BMDP and SAS (was R in clinical trials)
I used both BMDP and SAS in my earlier years, side by side. At that
time the BMDP statistical methods were much more mature and
comprehensive: we treated them as the standard when the two packages
disagreed. (It was a BMDP manual that clearly explained to me what the
hypothesis of "Yate's weighted mean test" is, something SAS decided to
call "type III" and eternally
2002 Sep 13
0
Sample size for factorial clinical trials with survival endpoints
Dear All,
I am looking an R version of the "Computer program for sample size and
power calculations in the design of multi-arm and factorial clinical trials
with survival endpoints".
Best regards,
Giovanni Parrinello
P.S.: in the meantime I am preparing a summary for my preceeding question
about time-varying covariates in the Cox model and
I thank Frank Harrell, Chuck Cleland,
2011 May 31
0
Finding the adjusted confidence intervals in a group sequential trials (akin to GroupSeq), but in a simulation setting
Hi there,
I want to find the adjusted confidence intervals in group sequential trials
in a simulation setting. GroupSeq provides me with what I am looking for in
an interactive setting, but I am not sure how to make it work in a
simulation setting so that it produces a series of adjusted confidence
intervals for a series of Z-statistics that I provide it without me having
to enter each