Displaying 20 results from an estimated 11000 matches similar to: "t test problem?"
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
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
2013 Oct 02
5
Interpreting the result of a Wilcoxon (Mann-Whitney U) test
Hello everyone,
I'm having some trouble interpreting the results of a Wilcoxon
(Mann-Whitney U) test. Hope you can help.
This is the R script that I am running:
a <- c(1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 2, 1, 5, 1, 1, 1, 3, 1, 1,
1, 1, 1, 1, 3, 1, 1)
b <- c(1, 2, 1, 1, 2, 3, 2, 2, 1, 2, 1, 1, 1, 2)
wilcox.test(a, b, alternative="t", mu=0, exact=FALSE, paired=FALSE) #1st
2010 Jun 23
3
Wilcoxon signed rank test and its requirements
Hi all,
I have a distribution, and take a sample of it. Then I compare that sample with the mean of the population like here in "Wilcoxon signed rank test with continuity correction":
> wilcox.test(Sample,mu=mean(All), alt="two.sided")
Wilcoxon signed rank test with continuity correction
data: AlphaNoteOnsetDists
V = 63855, p-value = 0.0002093
alternative hypothesis:
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.
2009 Mar 02
3
Help with Wilcoxon Test
Hi
I have 2 sets of data that I want to do a Wilcoxon test on. They are of the same dimension. One has 4 zero values and the other has 5.
> dim(SampA)
[1] 1 10
> dim(SampV)
[1] 1 10
I get the folowing error
Error in wilcox.test.default(SampA, SampV, na.rm = TRUE, paired = FALSE, :
'x' must be numeric
I am using the function
wilcox.test(SampA, SampV, na.rm=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)
2012 Jul 24
2
Wilcoxon V = 0
I am running a pairwise wilcoxon signed rank test, and I am not sure how to
interpret the result. I would like to see if there is a difference between
the values in conditions a and b. It doesn't seem possible to have a V = 0,
but a significant p value. Am I doing something wrong?
The command I used is this:
wilcox.test(x=a$x,y=b$x,paired=TRUE)
The output looks like this:
Wilcoxon
2012 Nov 25
2
Finding the Degrees of Freedom in a Wilcoxon Test
Dear R-ers,
I am currently running some Wilcoxon tests in R-64.
How do I find the degrees of freedom in the output I am receiving?
> wilcox.test(good$TRUE, good$x4a, paired=FALSE)
Wilcoxon rank sum test with continuity correction
data: good$TRUE and good$x4a
W = 2455, p-value < 2.2e-16
alternative hypothesis: true location shift is not equal to 0
Thank you,
Stephen.
2010 Nov 24
3
Límites de confianza de la mediana en distribuciones simétricas
Por si alguno pudiera ayudarme.
Al realizar el t.test para una muestra, junto con el valor de t y el
p-valor, la función proporciona la estimación de la media y su INTERVALO
DE CONFIANZA.
Desde el punto de vista de la estadística de rangos esto se puede hacer
mediante:
> iris$MEDIANA <- with(iris, 2.95)
> median(iris$Sepal.Width - iris$MEDIANA, na.rm=TRUE) # median difference
[1]
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
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
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 =
2007 Jun 28
1
Wilcoxon Rank Sum Test.
Dear,
I'm using R software to evaluate Wilcoxon Rank Sum Test and I' getting one
Warning message as this:
> C1dea_com
[1] 1.000 0.345 0.200 0.208 0.508 0.480 0.545 0.563 0.451 0.683 0.380 0.913
1.000 0.506
> C1dea_sem
[1] 1.000 0.665 0.284 0.394 0.509 0.721 0.545 0.898 0.744 0.683 0.382 0.913
1.000 0.970
> wilcox.test(C1dea_sem,C1dea_com, paired = TRUE, alternative =
2011 Sep 15
1
How to compute the power of a wilcoxon test?
Hello All,
I posted a similar question before, but the direction was driven to whether
my case is suitable for a wilcoxon test. After research about the
appropriateness, I am pretty sure that a wilcoxon test is the right tool for
my case. But how to compute the power of the test is still an unanswered
question bothering me.
The basic stats of my two paired samples are:
mean1 = 0.0032, sd1 =
2012 Aug 08
1
Wilcoxon test
Dear list,
I am facing a problem in my statistical analyses on R.
My experiments are about plants, I record there growth after each cutting (every 3 weeks).
'BC' is for the plant, and '1' to '5' is the time of cutting and recording.
The data and R script are :
""
BourdCoup <- c(21, 7.2, 9.2, 0, 8.52, 14.7, 8.31, 6.2, 127.05, 115.2, 100.7, 24, 162.64, 136.8,
2008 Apr 13
2
Arrays and functions
Hi, I' am doing a stats project using R to work out the size of a t-test and wilcoxon test depending on the distribution and sample size. I just can't get it to work - I want to put my results from the function size() into an array.At the moment I keep getting the error message:Error in res[distribution, test, samplesize] <- results : subscript out of boundsCan anyone tell me where
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:
2010 Aug 25
2
Comparing samples with widely different uncertainties
Hi
This is probably more of a statistics question than a specific R
question, although I will be using R and need to know how to solve the
problem in R.
I have several sets of data (ejection fraction measurements) taken in
various ways from the same set of (~400) patients (so it is paired data).
For each individual measurement I can make an estimate of the percentage
uncertainty in the
2011 Apr 13
2
Wilcoxon rank sum in unbalanced design
Hi everyone!
I need to perform a Wilcoxon rank sum test, but I have some ties and the
groups have different size also. When I deal with ties I use the
wilcox.exact function, how can I solve the different size problem using this
function?
thanks
net
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