Displaying 20 results from an estimated 1000 matches similar to: "How to run Shapiro-Wilk test for each grouped variable?"
2010 May 25
2
Get output values in a table
Hi,
I use two similar scripts to put p-values of shapiro.test and, respectively,
of wilcox.test in a table:
a)
d <- data.frame(dataset$GroupFactor, dataset[2:11])
# p-values for the shapiro test (by levels of GroupFactor)
with(d, aggregate(d[,-1], list(d[,1]), FUN = function(x)
shapiro.test(x)$p.value))
b)
d <- data.frame(dataset$GroupFactor, dataset[2:11])
with(d, aggregate(d[,-1],
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 <-
2010 Aug 17
3
Wilcoxon test and grouping factor with multiple levels
Dear R users,
I have a dataset with two variables: $esan - a grouping factor with 8
levels and $reus. I'd like to do wilcox.test on this dataset as
sugested Weiwei here:
https://stat.ethz.ch/pipermail/r-help/2007-July/136627.html. I tried
to adapt his recommendation but no succes. Can anyone help me?
Regards,
Iurie Malai, Senior Lecturer
Department of Psychology
Faculty of Psychology and
2009 Oct 23
4
How to apply the Wilcoxon test to a hole table at once?
Hi,
I have a data set:
> Dataset
X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15 X16 X17
1 user1 m 22 19 28 24 12 18 9 7 4 5 4 7 5 7 9
2 user2 f 25 19 23 18 18 15 6 8 6 6 7 10 7 7 7
3 user3 f 28 21 24 18 15 12 10 6 7 9 5 10 5 9 5
4 user4 f 26 19 26 21 12 18 6 6 5 1 3 8 6 5 6
5 user5 m 21 22 26 18 9 6 4 6 1
2010 Mar 21
2
Levene's Test for Homogeneity of Variance
Hi, All!
To calculate Levene's Test for Homogeneity of Variance I use R Commander,
and this is the output:
> levene.test(Dataset$age, Dataset$sex)
Levene's Test for Homogeneity of Variance
Df F value Pr(>F)
group 1 0.8739 0.3567
33
I am not sure what means "Pr(>F)"? Can anyone explain/translate this?
Regards,
Iurie Malai
Department of Psychology and
2011 Apr 15
1
Launcher for Rattle?
How to make a launcher for Rattle?
Regards,
Iurie Malai
Moldova Pedagogical State University
[[alternative HTML version deleted]]
2012 Nov 05
1
A general question: Is language S a component part of R?
In the "Introduction and preliminaries" the "An Introduction to R" manual
says about R: "... Among other things it has ... a well developed, simple
and effective programming language (Called 'S') ... ". Now I'm a little
confused. This means that language S is a component part of R? And S is not
free? But R is free? Or the mentioned S is only "a free
2001 Jul 02
2
Shapiro-Wilk test
Hi,
does the shapiro wilk test in R-1.3.0 work correctly? Maybe it does, but can
anybody tell me why the following sample doesn't give "W = 1" and
"p-value = 1":
R> x<-1:9/10;x
[1] 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
R> shapiro.test(qnorm(x))
Shapiro-Wilk normality test
data: qnorm(x)
W = 0.9925, p-value = 0.9986
I can't imagine a sample being
2000 Sep 25
1
Interpretation of Shapiro-Wilk
Can anybody tell me the exact meaning of the $statistic and $p.value
calculated by shapiro.test? Unfortunately it is not covered in my few
text books, and I cannot find the explanation in the R documentatiom or
on-line.
If I have a test statistic, T, which is Normally distributed with mean=m
and sd=s under the null hypothesis, then I can convert T to a p-value
(one-sided) using:
p <- pnorm(T,
2012 Apr 04
1
Shapiro-Wilk cpoefficients: 2 Qs
Greetings!
I want to have the coefficients that R uses in shapiro.test()
for the Shapiro-Wilk test for a prticular sample size, i.e.
the a[i] in
W = Sum(a[i]*x[i])/(Sum(x[i] - mean(x))^2)
(where the x[i] are sorted). Two questions:
Q1:
Is there a readymade R function from which I can extract these?
Q2:
I was wondering if I might be able to modify the code for the
function shapiro.test() so
2013 Apr 05
2
How to perform a grouped shapiro wilk test on dataframe
Hello,
I was wandering if it is possible to perform on a dataframe called 'all' a
shapiro wilk normality test for COUNTS by variable Group
ACTIVITY? Could it be done using plyer? I saw an eg that applies to an
array but not to a dataframe:
lapply(split(dataset1$Height,dataset1$Group),shapiro.test)
Any thoughts would be much appreciated.
My dataframe is in shape:
dat ACTIVIT
2008 Jul 12
5
shapiro wilk normality test
Hi everybody,
somehow i dont get the shapiro wilk test for normality. i just can?t
find what the H0 is .
i tried :
shapiro.test(rnorm(5000))
Shapiro-Wilk normality test
data: rnorm(5000)
W = 0.9997, p-value = 0.6205
If normality is the H0, the test says it?s probably not normal, doesn
?t it ?
5000 is the biggest n allowed by the test...
are there any other test ? ( i know qqnorm
1999 Nov 04
1
shapiro wilk
I'm pretty new to R and are trying to do some reliable normality
testing... but, can't find the Shapiro Wilk test in R Does some
experienced user have such a function that will be wanting to share with
me? Or there is maybe some other way to get hte Shapiro Wilk test
done... I'll appreciate any hint on this,
Thanks
--
***********************
Horacio Samaniego
Dep. Ecologia
P.
2008 Jan 13
1
Shapiro-Wilk
What is the formula used in Shapiro-Wilk Statistic?
Thanks
Eduardo (S?o Paulo/ Brazil)
2010 Feb 18
1
Shapiro-Wilk test problem
Hi everybody,
Does anyone know what problem may be with this test.
I am applying 5 different normality tests and use p-values for them, but for
some reason S-W gives me NA, while sample size is 100.
Any ideas?
Thanks a lot!
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2012 Feb 08
0
How to start JGR in full window?
I want to start JGR as a full sized/maximized window automatically, but how
to do this? For other applications I can add option "--geometry 1440x900"
to the launch command, but for JGR this do not work. Sugestions?
Iurie Malai
Senior Lecturer
Psychology Department
Ion Creanga Moldova Pedagogical State University
[[alternative HTML version deleted]]
2005 Nov 09
1
Problems with Shapiro Wilk's test of normality.
Hi,
I am trying to create a table with information from Shapiro Wilk's
test of normality.
However, it fails due to lack of sample size, it says, but the way I
see it, this is not a problem.
(See the table of sample sizes (almost) at the bottom).
Applying a different function using a similar ftable call is not a
problem (See the bottom table).
This is R 2.1.0 on Linux (Gentoo).
/Fredrik
2008 Oct 09
1
interpreting Shapiro-Wilks test result
Hi all,
I am newbie in using R software and also doing statistical test. I want to know if my data in in normal distribution. I have 2 groups of data and I did calculate Shapiro Wilks using R software. Here is the results:
Group 1: W = 0.9206, p-value = 0.01683
Group 2: W = 0.9626, p-value = 0.4694
I am not quite sure what default confidence level (CF) is used in calculating Shapiro Wilks.
2005 May 03
1
multivariate Shapiro Wilks test
Hello,
I have a question about multivariate Shapiro-Wilks test.
I tried to analyze if the data I have are multivariate normal, or how
far they are from being
multivariate normal. However, any time I did
>mshapiro.test(mydata)
I get the message:
Error in solve.default(R %*% t(R), tol = 1e-18) :
system is computationally singular: reciprocal condition number
= 5.38814e-021
I tried
2008 Jul 14
0
"Reasonable doubt" - was "Re: shapiro wilk normality test"
>>> Ted Harding <Ted.Harding at manchester.ac.uk> 14/07/2008 00:16 >>>
>said:
>What constitutes "reasonable doubt" can become a very interesting
>question, but there are some crimes for which it has a definite
>statistical interpretation
Warning for potential courtgoers: "reasonable doubt" NEVER has a direct
statistical interpretation in a