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 want to play anymore. Running Jorge's code seemed at
first to be pretty good evidence that doing such an investigation is
prone to very misleading results to which I would not want to expose
the unwary. Only one of those thirty "tests of normality" on what
appeared at first glance to be "normal" data actually accepted the
Null Hypothesis.
(That arose because he only selected 100 normal values and then
replicated them across 10 and 100 rows and columns. You can prove this
by table(unlist(d[,-1]) ), so I suppose the widespread rejection could
be considered a proper result. Notice that d[11,2] == d[1,20] )
Automating the task of testing for normality reminds me of the methods
I was forced to use in Green Belt class, although their favorite
"normality" statistic was the Anderson-Darling test. I had by that
point decided to bite my tongue because the Black Belt instructors
were rather annoyed at hearing my objections and pained reactions to
their version of statistics.
--
David.
Iurie
2010/4/9 David Winsemius <dwinsem...@comcast.net>:
OK, we have the data, now ... where is the code that you used to
read that
data? It is labeled as a csv file but does not have commas as
separators.
Post any follow-ups to the r-help list. I do not offered offlist
consulting.
When you post data to the list it needs to have a file extension of
".txt"
--
David
On Apr 9, 2010, at 10:08 AM, Iurie Malai wrote:
I attached a file with data and corrected in the working commands
grouping factor name:
data.n<-names(data) # put names into a vector called data.n
by(eval(parse(text=(paste("data",data.n[3],sep="$")))), data
$groupFactor,
shapiro.test) # run shapiro.test
and not working:
for (r in 3:18) {
by(eval(parse(text=(paste("data",data.n[3],sep="$")))), data
$groupFactor,
shapiro.test)
}
2010/4/9 David Winsemius <dwinsem...@comcast.net>:
On Apr 9, 2010, at 8:16 AM, Iurie Malai wrote:
I want to run Shapiro-Wilk test for each variable in my dataset,
each
grouped by variable groupFactor.
I have these working commands:
data.n<-names(data) # put names into a vector called data.n
by(eval(parse(text=(paste("data",data.n[3],sep="$")))), data
$factor,
shapiro.test) #run shapiro.test
but I must to change the variable number manualy. How to
automate this?
I tried this:
for (r in 3:18) {
by(eval(parse(text=(paste("data",data.n[3],sep="$")))),
data$groupFactor,
shapiro.test)
}
Not able to test since you have provided code that works with
data that
is
not available. Inside for loops one needs either to make an
assignment or
print the results. Had the data been available I would have wrapped
print()
around the full by expression to see if my hypothesis could be
tested.
--
David.
but not working and no errors. Why?
Please help.
--
Regards,
Iurie Malai, Senior Lecturer
Department of Psychology
Faculty of Psychology and Special Education
Ion Creanga Moldova Pedagogical State University - www.upsm.md
http://en.wikipedia.org/wiki/Ion_Creang%C4%83_Pedagogical_State_University
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
West Hartford, CT
<data.csv>
David Winsemius, MD
West Hartford, CT
--
Regards,
Iurie Malai, Senior Lecturer
Department of Psychology
Faculty of Psychology and Special Education
Ion Creanga Moldova Pedagogical State University - www.upsm.md
http://en.wikipedia.org/wiki/Ion_Creang%C4%83_Pedagogical_State_University
<data.txt>______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
West Hartford, CT
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
