Displaying 20 results from an estimated 3000 matches similar to: "Problem with "Cannot compute correct p-values with ties""
2009 Nov 06
2
How to test user-defined distribution using ks.test in R?
Dear All,
I defined a distribution and I want to test it by k-s test?
How to input parameters for ks.test(.....)?
E.g.,
F(x,m) is user-defined function
x is observation value, m is parameter of F
y is observation vector value in experiment
> ks.test(y,"F",m=0.2)
error....
why?
'
--
Best wishes,
Zhijiang Wang
--------------------------------------------
PHD Student
Room
2006 Aug 25
1
exact Wilcoxon signed rank test with ties and the "no longer under development" exactRanksumTests package
Dear List,
after updating the exactRanksumTests package I receive a warning that
the package is not developed any further and that one should consider
the coin package.
I don't find the signed rank test in the coin package, only the Wilcoxon
Mann Whitney U-Test. I only found a signed rank test in the stats
package (wilcox.test) which is able to calculate the exact pvalues but
unfortunately
2002 Sep 26
1
T-Value, ties and the wilcox.test()
hi,
i am looking for a way to correct for ties in the wilcoxon signed rank
test -> e.g. wilcox.test(x,mu=.5)
one way i have heard of is to look up the p value in a table that has
been produced by Buck (1975). obviously i need to know the T-value to do
that -> how do i get the T-value from the wilcox.test() function.
is there any other (already implemented) way to correct for ties in
2008 Apr 30
1
What are ties? Wilcox u-test
Hi,
When I execute a Wilcox u-test on two variables I receive a warning :
'cannot compute exact p-value with ties'
- What are ties? What does this mean for my data?
- Is that a problem for significance testing?
- is there a way to overcome this problem?
I have different threads in this forum but it hard to find what the exact
meaning of this warning message is.
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View this message in
2011 Aug 17
4
Puppet agent hangs for over a minute, no info in --summarize
Hoping you guys might be able to help me out, I''m not sure what''s
wrong but puppet agent hangs for over a minute, no resource spikes
(CPU, memory, etc all stay basically the same as without starting
puppet, barely a blip, and I''ve got more than enough headroom). It''s
not a serious issue for continuous usage, but really, really annoying
when testing the manifests
2011 Apr 12
2
The three routines in R that calculate the wilcoxon signed-rank test give different p-values.......which is correct?
I have a question concerning the Wilcoxon signed-rank test, and
specifically, which R subroutine I should use for my particular dataset.
There are three different commands in R (that I'm aware of) that calculate
the Wilcoxon signed-rank test; wilcox.test, wilcox.exact, and
wilcoxsign_test. When I run the three commands on the same dataset, I get
different p-values. I'm hoping that
2005 Nov 14
1
effect sizes for Wilcoxon tests
Hello,
I use t.test for normal distributed and wilcox.test for non-normal
distributed samples.
It is easy to write a function for t.test that calculates the effect
size, because all parts of the formula are available from the t.test
result: r = sqrt(t*t / (t*t + df))
However, for Wilcoxon tests, the formula for effect sizes is:
r = Z / sqrt(N)
I wonder how I can calculate the Z-score in R for
2009 Oct 23
4
How to apply the Wilcoxon test to a hole table at once?
Hi,
I have a data set:
> Dataset
X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15 X16 X17
1 user1 m 22 19 28 24 12 18 9 7 4 5 4 7 5 7 9
2 user2 f 25 19 23 18 18 15 6 8 6 6 7 10 7 7 7
3 user3 f 28 21 24 18 15 12 10 6 7 9 5 10 5 9 5
4 user4 f 26 19 26 21 12 18 6 6 5 1 3 8 6 5 6
5 user5 m 21 22 26 18 9 6 4 6 1
2013 May 30
1
wilcox_test function in coin package
Dear All,
I have two simple data samples (no groups or factors, etc.) and would just
like to compute the two-sample Wilcoxon Rank Sum test using the wilcox_test
function contained in the coin package, which is reportedly better than the
regular wilcox.test function because it performs some adjustment for ties.
Would anyone know how to craft a script to perform this task? Much
appreciated.
Janh
2003 Dec 01
2
wilcoxon-pratt signed rank test in R - drug-effiacy
Hi.
I'm going to introduce the R-package for a group of medical doctors later
this week and is a little confused about there use of a test named
"willcoxon-pratt" for testing if the clinical and biochemical markers has
decreased significantly after the use of some drugs for a group of patients.
Looking into the R-functions I would in R recommand using a matched-pairs
Wilcoxon
2010 Feb 05
1
Hodges-Lehmann EXACT confidence interval for small dataset with ties
Dear r-helpers,
I have a small dataset (n<50), and I want to compute the Hodges Lehmann
exact confidence interval.
So far, I know that "pairwiseCI" has the function "HL.diff". The description
is as follows :
HL.diff calculates the Hodges-Lehmann confidence interval for the difference
of locations by calling wilcox.exact in package exactRankTests ;
But when I check
2019 Dec 12
2
Inconsistencies in wilcox.test
>>>>> Karolis Koncevi?ius
>>>>> on Mon, 9 Dec 2019 23:43:36 +0200 writes:
> So I tried adding Infinity support for all cases.
> And it is (as could be expected) more complicated than I thought.
"Of course !" Thank you, Karolis, in any case!
> It is easy to add Inf support for the test. The problems start with conf.int=TRUE.
2019 Dec 07
5
Inconsistencies in wilcox.test
Hello,
Writing to share some things I've found about wilcox.test() that seem a
a bit inconsistent.
1. Inf values are not removed if paired=TRUE
# returns different results (Inf is removed):
wilcox.test(c(1,2,3,4), c(0,9,8,7))
wilcox.test(c(1,2,3,4), c(0,9,8,Inf))
# returns the same result (Inf is left as value with highest rank):
wilcox.test(c(1,2,3,4), c(0,9,8,7), paired=TRUE)
2019 Dec 07
2
Inconsistencies in wilcox.test
Thank you for a fast response. Nice to see this mailing list being so
alive.
Regarding Inf issue: I agree with your assessment that Inf should not be
removed. The code gave me an impression that Inf values were
intentionally removed (since is.finite() was used everywhere, except for
paired case). I will try to adjust my patch according to your feedback.
One more thing: it seems like you
2011 Oct 31
2
one sample Wilcoxon test using 'coin'
Hi,
R allows me to run a one sample Wilcoxon test like this:
wilcox.test(c(1,3.5,2.1,4,1.5,5), mu=2, exact=TRUE)
The function 'wilcoxsign_test' from the package 'coin' should (I
suppose) be able to calculate exact p values even if there are ties in
the ranks. However, I couldn't find information on how to run a one
sample test using 'wilcoxsign_test' like in the
2011 Jun 14
4
BIZARRE results from wilcox.test()
I get these BIZARRE results from wilcox.test()
When INCREASING the number of samples i get INCREASED p-values. When
increasing the number of samples further, the p-values goes down again. This
seems really bizarre!
Can anyone explain why this is so?!
Example:
> w <- wilcox.test(c(1:40),(c(1:40)+100))
> w$p.value
[1] 1.860340e-23
> w <- wilcox.test(c(1:50),(c(1:50)+100))
>
2010 Oct 29
2
wilcox.test; data type conversion?
I'm working on a quick tutorial for my students, and was planning on
using Mann-Whitney U as one of the tests.
I have the following (fake) data
grade <- c("MVG", "VG", "VG", "G", "MVG", "G", "VG", "G", "VG")
sex <- c( "male", "male", "female", "male",
2015 Jul 10
2
[LLVMdev] Windows interface for clang
I've finally developed what I think is a general solution to the problem of
building existing Windows programs with clang:
https://github.com/russellw/wic
Using this, I've managed to run attempted builds of Python, Ruby and Perl.
Python 2.7 works - it generates a python.exe that at least passes a
preliminary smoke test.
Perl generates an executable that crashes partway through the
2009 May 19
1
Wilcoxon nonparametric p-values
When I use wilcox.test, I get vastly different p-values than the problems
from Statistics textbooks.
For example:
The following problem comes from "Applied Statistics and Probability for
Engineers", 2nd Edition, by D. C. Montgomery. Page736, problem 14.7. The
problem is to compare the sample data with a population median of 8.5. The
book answer is p = 0.25, wilcox.test answer is p =
2010 Aug 09
1
Difference Between R: wilcox.test and STATA: signrank
This is my first post to the mailing list and I guess it's a pretty stupid
question but I can't figure it out. I hope this is the right forum for these
kind of questions.
Before I started using R I was using STATA to run a Wilcoxon signed-rank
test on two variables. See data below: