Displaying 20 results from an estimated 10000 matches similar to: "Wilcoxon test p value with one decimal place"
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 =
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
2012 May 29
2
Wilcoxon-Mann-Whitney U value: outcomes from different stat packages
Given this example
#start code
a<-c(0,70,50,100,70,650,1300,6900,1780,4930,1120,700,190,940,
760,100,300,36270,5610,249680,1760,4040,164890,17230,75140,1870,22380,5890,2430)
b<-c(0,0,10,30,50,440,1000,140,70,90,60,60,20,90,180,30,90,
3220,490,20790,290,740,5350,940,3910,0,640,850,260)
wilcox.test(a, b, paired=FALSE)
#sum of rank for first sample
sum.rank.a <-
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
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)?
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
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
2005 May 16
1
Mann-Whitney & Wilcoxon Rank Sum
Hello,
I am hoping someone could shed some light into the Wilcoxon Rank Sum Test
for me? In looking through Stats references, the Mann-Whitney U-test and
the Wilcoxon Rank Sum Test are statistically equivalent. When using the
following dataset:
m <- c(2.0863,2.1340,2.1008,1.9565,2.0413,NA,NA)
f <- c(1.8938,1.9709,1.8613,2.0836,1.9485,2.0630,1.9143)
and the wilcox.test command as
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
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 =
2012 Feb 09
2
AUC, C-index and p-value of Wilcoxon
Dear all,
I am using the ROCR library to compute the AUC and also the Hmisc library
to compute the C-index of a predictor and a group variable. The results of
AUC and C-index are similar and give a value of about 0.57. The Wilcoxon
p-value is <0.001! Why the AUC is showing small value and the p-value is
high significant? The AUC is based on Wilcoxon calculation?
Many thanks,
Lina
2009 Dec 02
5
Problem with "Cannot compute correct p-values with ties"
Dear All,
1. why did the problem happen?
2. How to solve it?
--
Best wishes,
Zhijiang Wang
--------------------------------------------
PHD Student
Room 212, Science buliding,
The International WIC Institute,
College of Computer Science and Technology,
Beijing University of Technology,
Beijing, China.
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
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:
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,
2010 Nov 24
2
Wilcoxon Rank Sum in R with a multiple testing correction
Hi there,
I'm a total newbie to R. I'd like to use a Wilcoxon Rank Sum test to compare
two populations of values. Further, I'd like to do this simultaneously for
114 sets of values. The two populations are C and N. The different sets of
values have arbitrary names (I'll call them a, b, c etc). The set-up is as
follows:
a b c d ....
C 2
C 3
C 5
C 9
C 4
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 Jun 05
3
Wilcoxon test output as a table
Hi!
I searched some time ago a way to get the Wilcoxon test results as a table
more or less formatted. Nobody told me any solution and I found nothing on
the Internet. Recently I came across this link (
http://myowelt.blogspot.com/2008/04/beautiful-correlation-tables-in-r.html),
which helped me to find a solution.
Here's the solution (I'm using R Commander):
W <-
2003 Jun 11
1
qwilcox
The function 'wilcox.test' in R and S gives (almost) identical results (see
below). 'qwilcox' however, does not:
> qwilcox(p,5,5)
p: 0.025 0.975
--------------------
R> 3 22
S> 18 37
I originally wanted to ask a questions, but then I found the answer. Given
the confusion I run into, I wonder if this experience is worth reporting.
The