R help - Jun 2007 - tapply

Hello, I want to conduct normality test to a series of data and get the
p-value for each subset. I am using the following codes, but it does not
work.

tapply(re, list(reg, ast), pvalue(shapiro.test))

Could anyone give me some advice? Many thanks.
-- 
View this message in context:
http://www.nabble.com/tapply-tf3851631.html#a10910748
Sent from the R help mailing list archive at Nabble.com.

I'm not sure what is the 'pvalue' function (it's not found in
base nor
stats packages) but
this should give you what you want:

# some example
re <- rnorm(100)
reg <- rep(1:3, length=100)
ast <- rep(1:2, length=100)

tapply( re, list(reg, ast), function(v) shapiro.test(v)$p.value )

# or neater by defining a function
p.shapiro <- function(v) shapiro.test(v)$p.value
tapply( re, list(reg, ast), p.shapiro )



hth,

michal
> Hello, I want to conduct normality test to a series of data 
> and get the
> p-value for each subset. I am using the following codes, but 
> it does not
> work.
> 
> tapply(re, list(reg, ast), pvalue(shapiro.test))
> 
> Could anyone give me some advice? Many thanks.

try this:

tapply(re, list(reg, ast), function(x) shapiro.test(x)$p.value)


I hope it helps.

Best,
Dimitris

----
Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://med.kuleuven.be/biostat/
     http://www.student.kuleuven.be/~m0390867/dimitris.htm


----- Original Message ----- 
From: "livia" <yn19832 at msn.com>
To: <r-help at stat.math.ethz.ch>
Sent: Friday, June 01, 2007 1:00 PM
Subject: [R] tapply

>
> Hello, I want to conduct normality test to a series of data and get 
> the
> p-value for each subset. I am using the following codes, but it does 
> not
> work.
>
> tapply(re, list(reg, ast), pvalue(shapiro.test))
>
> Could anyone give me some advice? Many thanks.
> -- 
> View this message in context: 
> http://www.nabble.com/tapply-tf3851631.html#a10910748
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at stat.math.ethz.ch 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.
> 

Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm