Iurie,
Noel, thanks a lot. This will help me someday. But I have a question.
When we run Shapiro-Wilk test, the homogenity of variances is a
mandatory condition?
No it is not. An homoscedasticity test only makes sense when you have a
grouping factor, and a normality test may of course be
On Tue, 13 Apr 2010, Yvonnick Noel wrote:
Iurie,
Noel, thanks a lot. This will help me someday. But I have a question.
When we run Shapiro-Wilk test, the homogenity of variances is a
mandatory condition?
No it is not. An homoscedasticity test only makes sense when you have a
grouping
Dear Iurie,
I want to run Shapiro-Wilk test for each variable in my dataset, each
grouped by variable groupFactor.
Note that, at least on a single dependent variable with a grouping variable, a
possible simplification may arise when homogeneity of variances is assumed and
reasonable. You may
Noel, thanks a lot. This will help me someday. But I have a question.
When we run Shapiro-Wilk test, the homogenity of variances is a
mandatory condition?
2010/4/12 Yvonnick Noel yvonnick.n...@uhb.fr:
Dear Iurie,
I want to run Shapiro-Wilk test for each variable in my dataset, each
grouped
I want to run Shapiro-Wilk test for each variable in my dataset, each
grouped by variable groupFactor.
I have these working commands:
data.n-names(data) # put names into a vector called data.n
by(eval(parse(text=(paste(data,data.n[3],sep=$, data$factor,
shapiro.test) #run shapiro.test
On Apr 9, 2010, at 8:16 AM, Iurie Malai wrote:
I want to run Shapiro-Wilk test for each variable in my dataset, each
grouped by variable groupFactor.
I have these working commands:
data.n-names(data) # put names into a vector called data.n
by(eval(parse(text=(paste(data,data.n[3],sep=$,
Hi,
Maybe you should change the 3 in the loop with r like:
for (r in 3:18) {
by(eval(parse(text=(paste(data,data.n[r],sep=$,
data$groupFactor, shapiro.test)
}
I think it should work, if not, I have already a similar script for that.
HTH,
Ivan
Le 4/9/2010 15:17, David Winsemius a écrit :
On Apr 9, 2010, at 9:39 AM, Ivan Calandra wrote:
Hi,
Maybe you should change the 3 in the loop with r like:
for (r in 3:18) {
by(eval(parse(text=(paste(data,data.n[r],sep=$, data
$groupFactor, shapiro.test)
}
I think it should work, if not, I have already a similar script for
that.
Thank you, David!
Here is the code to read my file:
data - read.table(data.txt, header=TRUE, sep=;, na.strings=NA,
dec=., strip.white=TRUE)
Jorge Ivan Velez gave me a working solution, but I am ready to learn yours to.
Iurie
2010/4/9 David Winsemius dwinsem...@comcast.net:
OK, we have the
Thank you very much, Jorge!
Your example worked for me. Here is the code:
d - data.frame(data$groupFactor, data[2:17])
d
# 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))
Iurie
2010/4/9 Jorge Ivan Velez
On Apr 9, 2010, at 10:51 AM, Iurie Malai wrote:
Thank you, David!
Here is the code to read my file:
data - read.table(data.txt, header=TRUE, sep=;,
na.strings=NA, dec=., strip.white=TRUE)
Jorge Ivan Velez gave me a working solution, but I am ready to learn
yours to.
I don't think I
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