Displaying 20 results from an estimated 5000 matches similar to: "Hodges-lehmann test and CI/significance"
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
2001 Oct 26
2
wilcox.test point estimates perverse (PR#1150)
The point estimates produced by wilcox.test are perverse (not wrong, just
brain damaged). The Hodges-Lehmann estimator that goes with the signed
rank test is the median of the Walsh averages. The Hodges-Lehmann estimator
that goes with the rank sum test is the median of the pairwise differences.
wilcox.test agrees except that it uses the following very peculiar definition
of "sample
2023 Dec 11
1
Base R wilcox.test gives incorrect answers, has been fixed in DescTools, solution can likely be ported to Base R
While using the Hodges Lehmann Mean in DescTools (DescTools::HodgesLehmann),
I found that it generated incorrect answers (see
<https://github.com/AndriSignorell/DescTools/issues/97>
https://github.com/AndriSignorell/DescTools/issues/97). The error is driven
by the existence of tied values forcing wilcox.test in Base R to switch to
an approximate algorithm that returns incorrect results - see
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
2003 Aug 21
1
comparing segments of a time series
Hi,
I have a time series of 38 wintertime average snow depths
measured at a particular meteorological station. The data appear to
undergo a "climate shift" in the early 1980s: before the shift the
mean and sd are 152 +/- 58, after the shift 92 +/- 36. The
distribution is not normal; there's a hard limit at zero of course and
there are outlier years with very high snowfall. I
2003 Aug 06
1
wilcox.test, CI (PR#3666)
Full_Name: David Wooff
Version: 1.7.0
OS: i686-pc-linux-gnu
Submission from: (NULL) (129.234.4.10)
wilcox.test exits with error message when confidence interval required, under
some situations. I suspect this occurs when the data contain a zero and for some
data lengths only:
print(wilcox.test(c(2,1,4,3,6,-5,0),conf.int=T))
fails
print(wilcox.test(c(2,1,4,3,6,-5,0,1),conf.int=T))
works
2024 Feb 12
0
Errors in wilcox family functions
Hi Everyone,
Following the previous discussion on optimizing *wilcox functions, Andreas Loeffler brought to my attention a few other bugs in `wilcox` family functions. It seems like these issues have been discussed online in the past few months, but I haven?t seen discussion on R-devel...unless I missed an email, it seems like discussion never made it to the mailing list. I haven?t seen any bug
2006 Dec 19
4
nonparametric significance test for one sample
Hello, Gurus:
I tried to test if the sample mean of a dataset is zero.
The data has 1500 numbers with a lot of zeros and some small
positive numbers. The data range on [0,1] but the distribution is unknown.
It is zero inflated anyway.
I tried to use the Wilcoxon Signed Ranks test. But I read from this website
that it does assume the population pdf is symmetric.
2006 Feb 15
3
wilcox.test returned estimates
Hi all,
I have being using wilcox.test to test for differences between 2 independent
samples. I had understood the difference in location to be conventionally the
difference in the sample medians however this is not the case when implemented
in R. I have tied ranks and therefore non-exact p-value and confidence
intervals are calculated due to the normal approximation. But what exactly is
this
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 =
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
2010 Aug 10
1
one (small) sample wilcox.test confidence intervals
Dear R people,
I notice that the confidence intervals of a very small sample (e.g. n=6) derived from the one-sample wilcox.test are just the maximum and minimum values of the sample. This only occurs when the required confidence level is higher than 0.93. Example:
> sample <- c(1.22, 0.89, 1.14, 0.98, 1.37, 1.06)
> summary(sample)
Min. 1st Qu. Median Mean 3rd Qu. Max.
2003 Feb 15
2
How to code a bootstrap version of the Wilcoxon-Mann-Whitney test (and variants)?
Hello,
can someone please help me with coding a function for a bootstrap WMW test (package boot, R under Windows, version 1.6.2)?
2000 Dec 18
2
Help: StatXact
Help needed!
Has anyone access to StatXact? I just hacked exact two-sided p-values for
rank tests (for package exactDistr, which will move to CRAN/contrib as
exactRankTests soon ;-) and would like to compare the results of my
implementation to that of StatXact. Could someone please calculate the
exact one-sided (both greater and less) and two-sided p-values?
# Data from the StatXact-4 manual,
2009 Oct 27
1
wilcox.exact() problem
Dear R friends,
here I write again about the wilcox.exact() problem. I want to compare two sets of categorical data, and in one case it says "negative length vectors not allowed", and in the other one I get the error "cannot allocate vector of length ...".
On http://rapidshare.com/files/298621893/wilcox.exact_trouble.Rdata.html you can download the data that cause the
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
2008 May 27
1
error in rsync protocol data stream (Marten Lehmann)
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2009 Oct 16
2
"negative length vectors are not allowed" in wilcox.exact() and perm.test()
Dear R friends,
I want to compare two datasets and I get the message
Error in .Call("cpermdist2", ma = as.integer(m), mb = as.integer(col), :
negative length vectors are not allowed
after specifying the exact test. I'm using the exactRankTests package. Do you suggest me using the coin library, or is there anything "wrong" with my data?
Kind regards,
David
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2012 Jul 12
1
permutation test on paired samples
Hi,
I'm trying to run a permutation test on paired samples.
First I tried the package "exactRankTests":
require("exactRankTests")
x <- c(1.83,0.50,1.62,2.48,1.68,1.88,1.55,3.06,1.30)
y <- c(0.878,0.647,0.598,2.05,1.06,1.29,1.06,3.14,1.29)
wilcox.test(x,y,paired = TRUE,alternative = "greater")
perm.test(y,x,paired = TRUE,exact = TRUE,alternative =
2005 Jun 28
1
nonparametric 2way repeated-measures anova
Dear useRs
is there any nonparametric test for the analysis of variance in a design
with two within-factors (repeated measures on both factors)? Friedman is not
appropriate here, therefore I am grateful for any alternative test.
thanks for any hint
cheers
christoph
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