Displaying 20 results from an estimated 1000 matches similar to: "Poission distribution"
1999 Apr 09
7
Error in ppois function (PR#161)
Full_Name: Murray H Smith
Version: 0.63.3
OS: Windows NT
Submission from: (NULL) (130.216.5.57)
The ppois function is displaced by -0.5.
Try:
> ppois(-0.5,1)
[1] 0.3678794
> ppois(-0.51,1)
[1] 0
> ppois(0,1)
[1] 0.3678794
and
> par(mfrow=c(2,1))
> x<-seq(-1,5,0.01)
> plot(x,ppois(x,1),type="s",ylab="F(x)",main="Poisson CDF?")
>
2004 Jan 15
1
Exactness of ppois
Hello,
by checking the precision of a convolution algorithm, we found the
following "inexactness":
We work with R Version 1.8.1 (2003-11-21) on Windows systems (NT, 2000,
XP).
Try the code:
## Kolmogorov distance between two methods to
## determine P(Poisson(lambda)<=x)
Kolm.dist <- function(lam, eps){
x <- seq(0,qpois(1-eps, lambda=lam), by=1)
max(abs(ppois(x,
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
2006 Jun 30
2
Query : Chi Square goodness of fit test
I want to calculate chi square test of goodness of fit to test,
Sample coming from Poisson distribution.
please copy this script in R & run the script
The R script is as follows
########################## start
#########################################
No_of_Frouds<-
c(4,1,6,9,9,10,2,4,8,2,3,0,1,2,3,1,3,4,5,4,4,4,9,5,4,3,11,8,12,3,10,0,7)
N <- length(No_of_Frouds)
# Estimation of
2011 May 06
2
coxph and survfit issue - strata
Dear users,
In a study with recurrent events:
My objective is to get estimates of survival (obtained through a Cox model) by rank of recurrence and by treatment group.
With the following code (corresponding to a model with a global effect of the treatment=rx), I get no error and manage to obtain what I want :
data<-(bladder)
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
2018 Dec 04
3
Bug report: Function ppois(0:20, lambda=0.9) does not generate a non-decreasing result.
Le 04/12/2018 ? 11:27, I?aki Ucar a ?crit?:
> On Tue, 4 Dec 2018 at 11:12, <qweytr1 at mail.ustc.edu.cn> wrote:
>> function ppois is a function calculate the CDF of Poisson distribution, it should generate a non-decreasing result, but what I got is:
>>
>>> any(diff(ppois(0:19,lambda=0.9))<0)
>> [1] TRUE
>>
>> Actually,
>>
>>>
2018 Dec 03
2
Bug report: Function ppois(0:20, lambda=0.9) does not generate a non-decreasing result.
function ppois is a function calculate the CDF of Poisson distribution, it should generate a non-decreasing result, but what I got is:
> any(diff(ppois(0:19,lambda=0.9))<0)
[1] TRUE
Actually,
> ppois(19,lambda=0.9)<ppois(18,lambda=0.9)
[1] TRUE
Which could not be TRUE.
Code is tested in both R 3.5.1 and Microsoft R Open 3.5.1.
_
2007 Jun 06
2
Multiple color schemes for barchart (lattice)
Hello R-help.
I am trying to make a stacked barplot where the color of the sections of
each bar depend on another variable.
> myData[1:11,]
score percent marker cellType Malignant
1 0 100.00000 ESR1 (ER) Bladder.M(5) TRUE
2 0 80.00000 PAX8 Bladder.M(5) TRUE
3 1 20.00000 PAX8 Bladder.M(5) TRUE
4 0 100.00000 ESR1 (ER) Brain.N(3) FALSE
5 0
2006 Sep 20
1
ppois
A quick question!
The number of episodes per year of otitis media follows a Possion
distribution with lambda = 1.6 episodes per year. Wouldn't the
probability of getting 3 or more episodes of otitis media in the first
2 years of life be:
> ppois(q=3, lambda=1.6*2, lower.tail = TRUE, log.p = FALSE)
[1] 0.6025197
I am confused with the lambda and 3 or more..
thx much
2011 Feb 25
1
Small enhancement for CMD check
It would be nice if the 00check.log file also included this part of the
output:
Running ?bladder.R?
Comparing ?bladder.Rout? to ?bladder.Rout.save? ... OK
Running ?book1.R?
Comparing ?book1.Rout? to ?book1.Rout.save? ... OK
Running ?book2.R?
Comparing ?book2.Rout? to ?book2.Rout.save? ... OK
etc.
The survival package has enough test scripts that it exceeds my
terminal's scroll
2009 Apr 20
1
bladder1 dataset in survival library
Hello,
In package survival should be a dataset bladder1.
http://stat.ethz.ch/R-manual/R-devel/library/survival/html/bladder.html
I can not open it (not found).
Both bladder and bladder2 are there.
Thanks,
Petra
2004 Jan 09
4
Poisson distribution help requested
Could somebody help me to understand the syntax of R's ppois function? I'm looking to calculate the cumulative probability density of an observed value (y) given the expected mean (mu) and the level of significance (alpha). I'm coming from using SAS to do this and don't recognize the descriptions of the arguments for ppois. The definitions of lambda and p as stated in the R manuals
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
2004 Jun 20
3
Greater than 1 or less than 1?
I have problem evaluating the expression h = exp(x)/(exp(exp(x))-1) for
large negative x. This expression is actually the probability
that y = 1 when y is a Poisson random variable truncated at 0, hence
must satisfy 0 <= h <= 1. However, when
x < -18, I may get an h value that is larger than 1 while the true
value should be a quantity that is smaller than but very close to 1.
For
2010 Oct 25
2
Ayuda con una función
Reciban un cordial saludo.
De manera muy comedida les pido ayuda con la función indicada abajo. La usan
en un artículo de inventarios. No veo dónde estoy errado.
Gracias de antemano.
César Escalante C.
> lamb<-50
> L<-1
> h.<-10
> p<-25
> K<-5
> integ<-function(y){integrate(function(x)ppois(x,lamb*L),0,y)$value}
> G<-function(y){(h.+p)*integ(y) +
2018 Apr 16
1
strange warning: data() error?
> On Apr 16, 2018, at 3:20 PM, David Winsemius <dwinsemius at comcast.net> wrote:
>
>>
>> On Apr 16, 2018, at 2:58 PM, Therneau, Terry M., Ph.D. via R-devel <r-devel at r-project.org> wrote:
>>
>> A user asked me about this and I can't figure it out.
>>
>> tmt% R
>> R Under development (unstable) (2018-04-09 r74565) --
2010 Mar 25
3
I have a question on nomograms.
Dear volunteer:
I am a graduate student of medcine in china.And now,I am devoting myself to constructing a nomograms of bladder cancer.I want to do it with R-project.However, I do not know how to construct a nomograms with R-project.I want to get yours help,thank you! I wish you can tell me the operating procedure of the R-project.
And I apologize for my english,it is poor,sorry!
1998 Mar 25
1
R-beta: qpois help
version .62:
---------------------------------------------
> ?qpois
The Poisson Distribution
dpois(x, lambda)
ppois(q, lambda)
qpois(p, lambda)
rpois(n, lambda)
Arguments:
x: vector of (positive) quantiles.
p: vector of probabilities.
n: number of random values to return.
lambda: vector of positive means.