Displaying 20 results from an estimated 800 matches similar to: "(no subject)"
2006 Jun 05
3
Fastest way to do HWE.exact test on 100K SNP data?
Hi everyone,
I'm using the function 'HWE.exact' of 'genetics' package to compute p-values of
the HWE test. My data set consists of ~600 subjects (cases and controls) typed
at ~ 10K SNP markers; the test is applied separately to cases and controls. The
genotypes are stored in a list of 'genotype' objects, all.geno, and p-values are
calculated inside the loop over all
2013 Mar 15
2
phyper returning zero
Hi,
I am attempting to use phyper to test the significance of two overlapping lists. I keep getting a zero and wondered if that was determining non-significance of my overlap or a p-value too small to calculate?
overlap = 524
lista = 2784
totalpop = 54675
listb = 1296
phyper(overlap, lista, totalpop, listb,lower.tail = FALSE, log.p=F)
[1] 0
If I plug in some different values I get a p-value but
2008 Sep 10
1
A question about the hypergeometric distribution and phyper()
Dear All
I have a question about the hypergeomteric distribution.
Example 1: I have a universe of 6187 objects, and 164 have a particular
attribute, therefore 6187-164 do not have that attribute. I sample 249
of those objects, and find that 19 have that attribute. I get a p-value
here (looking at just over-representation):
phyper(19, 164, 6187-164, 249, lower.tail=FALSE)
[1] 7.816235e-06
2004 Feb 04
3
number point under-flow
Hello,
I've come across the following situation in R-1.8.1 (compile + running under
RedHat 7.1):
> phyper(24, 514, 5961-514, 53, lower.tail=T)
[1] 1
> phyper(24, 514, 5961-514, 53, lower.tail=F)
[1] -1.037310e-11
I'd expect the later to be 0 or some very small positive number. Is this a
number under-flow of the calculation? Do you think I'm safe if I just set the
result to 0
2007 Oct 02
1
phyper returns negative results
Dear R-users,
In R 2.5.1 on Windows XP, SP2 the call to phyper(0,0,74,3,lower.tail=FALSE) returns -4.195862e-17. This does not happen with R2.5.1 on Linux, 0 is returned. Is this a bug (and should be reported as such), since phyper should not return negative values, or is this considered as one of the annoyances of finite precision arithmetic.
I tend to think of this as a bug since it breaks the
2016 Jan 14
2
RFC: Extend UBSan with qsort checks
On Thu, Jan 14, 2016 at 3:43 AM, Paul Pluzhnikov <ppluzhnikov at google.com> wrote:
> On Wed, Jan 13, 2016 at 4:17 PM, Kostya Serebryany <kcc at google.com> wrote:
>> Inviting Paul to the party (he wrote the libstdc++ sort checker).
>>
>> On Tue, Jan 12, 2016 at 11:09 PM, Yury Gribov <y.gribov at samsung.com> wrote:
>>>
>>> On 01/13/2016
2008 Feb 27
1
dhyper, phyper (PR#10853)
Aloha all,
I know too little about what I'm about to write and hope I'm not
wasting your time.
For a class I'm teaching in archaeological data analysis, I'm trying
to put together a routine that calculates the so-called Petersen
index and, especially, confidence intervals for the index. This was
introduced to archaeologists by N.R.J. Fieller and A. Turner in an
article
2006 Jan 18
1
phyper returns 1 if x==k (PR#8499)
Full_Name: Utz J. Pape
Version: 2.2.0
OS: linux
Submission from: (NULL) (141.14.23.12)
If I use phyper and set parameter x equal to k (meaning that all balls I draw
are white) phyper returns 1 which is not (always) correct:
pape at xxx:~> R2.2.0 --vanilla
R : Copyright 2005, The R Foundation for Statistical Computing
Version 2.2.0 (2005-10-06 r35749)
ISBN 3-900051-07-0
R is free software
2000 Mar 24
3
quantiles of the hypergeometric distribution (PR#502)
Hello!
I use R-version 1.0.0
To get the 0.95 quantile of the hypergeometric
distribution with the parameters m=45000,n=5000 and
k=600 I use the R-command
> qhyper(0.95,45000,5000,600).
The value obtained is 600. However, the true value
is 552. The latter can be obtained for example by
calling the corresponding distribution function
with the R commands
> x<-540:580
>
2003 Nov 14
2
Round error?
Hi all,
I have tried to compute a p-value for a hypergeometric distribution as:
dhyper(x,k,l,n) + phyper(x,k,l,n,lower.tail=FALSE)
and sometimes obtained negative values. Do you know if it is because a
round error or am I doing something wrong?
Thanks in advance,
Aurora
2010 Aug 13
1
hypergeometric vs fisher.test
Dear R team,
I have a simple question.
I tried this command:
phyper(17,449,19551,181, FALSE)
[1] 1.47295e-07
and then I tried this command:
(fisher.test(matrix(c(17,449,181,19551),2,2),
alternative='greater'))$p.value
[1] 3.693347e-06
Shouldn't be identical the results of the two commands ?
What is the difference ?
Thx a lot
--
View this message in context:
2000 Jun 15
1
proportions - finite population correction
> Dear R-users!
>
> I am using R 1.0.0 and Windows NT 4.0.
>
Suppose I have a population of N=100 subjects, a binomial variable and a
random sample of n=20 subjects from my population, giving 15 "successes". I
am interested in obtaining a confidence interval for the proportion of
"successes" in my population.
In R, I can use
> library(ctest)
>
2004 Jul 07
1
negative p-value from fisher.test() (PR#7064)
Full_Name: Anja von Heydebreck
Version: 1.9.1
OS: Linux
Submission from: (NULL) (155.250.128.25)
I obtained a negative p-value from the fisher.test() function:
> fisher.test(matrix(c(14576,3023,89,68),2), alternative="g")$p.value
[1] -8.426593e-13
With R 1.8.1, I got a p-value of -6.239231e-12 for this example.
Anja von Heydebreck
2010 Mar 30
1
Multivariate hypergeometric distribution version of phyper()
Dear R Users,
I employed the phyper() function to estimate the likelihood that the
number of genes overlapping between 2 different lists of genes is due to
chance. This appears to work appropriately.
Now i want to try this with 3 lists of genes which phyper() does not
appear to support.
Some googling suggests i can utilize the Multivariate hypergeometric
distribution to achieve this. eg.:
2006 Mar 28
2
R 2.3.0 (alpha) on FreeBSD 6.1 fails make check-all
Hi Developers,
The alpha, compiles successfully, but it is failing make check-all (on
two seperate machines, both FreeBSD 6.1).
Here is the version string:
platform i386-unknown-freebsd6.1
arch i386
os freebsd6.1
system i386, freebsd6.1
status alpha
major 2
minor 3.0
year 2006
month 03
day 27
svn rev
2013 Mar 21
2
Displaying median value over the horizontal(median)line in the boxplot
Hi,
set.seed(45)
test1<-data.frame(columnA=rnorm(7,45),columnB=rnorm(7,10)) #used an example probably similar to your actual data
apply(test1,2,function(x) sprintf("%.1f",median(x)))
#columnA columnB
# "44.5"? "10.2"
par(mfrow=c(1,2))
lapply(test1,function(x) {b<-
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
2011 Apr 28
5
fisher exact for > 2x2 table
I'm using fisher.exact on a 4x2 table and it seems to work.
Does anyone know exactly what is going on? I thought fisher.exact is only
for 2x2 tables.
Note: I can't use chi-squared because I have a couple of cells with 0 and <
5 observations.
--
View this message in context: http://r.789695.n4.nabble.com/fisher-exact-for-2x2-table-tp3481979p3481979.html
Sent from the R help
2016 Jan 14
2
RFC: Extend UBSan with qsort checks
Inviting Paul to the party (he wrote the libstdc++ sort checker
<https://gcc.gnu.org/svn/gcc/branches/google/gcc-4_9/libstdc++-v3/include/bits/stl_algo.h>
).
On Tue, Jan 12, 2016 at 11:09 PM, Yury Gribov <y.gribov at samsung.com> wrote:
> On 01/13/2016 10:08 AM, Yury Gribov wrote:
>
>> On 01/13/2016 09:57 AM, Kostya Serebryany wrote:
>>
>>> On Tue, Jan 12,