[R] convert sas date format

[peter dalgaard]

What does this have to do with date formats?? Please do not use "reply" to discuss unrelated matters; even if you change the header, threading mail readers will become confused.

Approach is a non-factor (the output says so), so treated as numerical, i.e. you are effectively doing a linear regression. You need to convert it to a factor first.

On Jan 28, 2012, at 01:38 , Johnny Liseth wrote:

> I am relatively new to R and I have problem figuring out why the data file
> appear to be read in fine, but the one way ANOVA is not calculated
> correctly. In other problems this works fine.
> 
> This program is listed at the end, and the small text file in online.
> 
> There are 24 data points in three groups of 8. Thus DF should be 3-1=2, not
> 1, and the



> residuals should be 24-1=23, not 22.
> 

Really? (Think again)


> I also get the warning,
> 
>> print(model.tables(aov.ex1,"means"),digits=3) #report the means and the
> number of subjects/cell
> Warning in replications(paste("~", xx), data = mf) :
> non-factors ignored: Approach
> 
> The grand mean is correct, but the mean for each group is not?
> 
> Any pointers would be appreciated.
> 
> Thanks,
> 
> Johnny Liseth
> Stat. Grad Student
> 
> #tell where the data come from
> datafilename="http://students.uwf.edu/ojl2/DE/prob3-5.txt"
> data.ex1=read.table(datafilename,header=T)                       #read the
> data into a table
> aov.ex1 = aov(Contributions~Approach,data=data.ex1)        #do the analysis
> of variance
> summary(aov.ex1)
> #show the summary table
> print(model.tables(aov.ex1,"means"),digits=3)
> boxplot(Contributions~Approach,data=data.ex1) #graphical summary
> 
> 	[[alternative HTML version deleted]]
> 
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-- 
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com