[R] trouble with model.tables SE means

[Charles C. Berry]

On Tue, 22 Dec 2009, David Winsemius wrote:

>
>
> On Dec 22, 2009, at 5:19 PM, Jon Prince wrote:
>> 
>> David Winsemius wrote:
>> > 
>> > On Dec 22, 2009, at 4:22 PM, Jon Prince wrote:
>> > 
>> > > Hi, I'm new to R, with some experience with Matlab and SPSS. I've 
>> > > figured out how to run my repeated measures anova and am getting the 
>> > > right numbers for my effects (comparing with results from other 
>> > > software), but am having trouble with the model.tables function. 
>> > > Specifically, using:
>> > > 
>> > > prints the means, but then won't do the SE values, instead giving:
>> > > 
>> > > Warning message:
>> > > In model.tables.aovlist(fm, "means", se = TRUE) :
>> > > SEs for type 'means' are not yet implemented"
>> > >

It means (no pun) what it says. see

 	?model.tables

---
Details:

      For .type = "effects". give tables of the coefficients for
      each term, optionally with standard errors.

      For .type = "means". give tables of the mean response for each
      combinations of levels of the factors in a term.
----

Notice that the 'optionally with standard errors' bit only pertains to 
"effects"

Chuck

>> > > Asking for SEs for "effects" works fine, but that's not what I want. I 
>> > > searched the help for this issue and one other person has had this 
>> > > problem last year 
>> > > (http://markmail.org/message/k5yxxqcfiihvzvtp?q=list:r-project+model%2Etables), 
>> > > but the person helping them was unable to replicate it, inferring that 
>> > > it was an out-of-date version. My version is:
>> > > 
>> > >  R version 2.10.1 (2009-12-14)
>> > > 
>> > > I only downloaded it the other day, and therefore cannot have an 
>> > > outdated version. How can I fix this error and get my SE values? 
>> > > Apologies if I have not provided sufficient information, and thanks in 
>> > > advance for your help.
>> > 
>> > When I look at the output of the first model.tables call copied from the 
>> > help page, I see a list element that holds "se" values. Try:
>> > 
>> > model.tables(fm,"means",se=TRUE)$se
>> > 
>> 
>> Thanks for the rapid reply! Unfortunately adding the $se returns NULL, and 
>> repeats the same warning message ("...not yet implemented"). If you're not 
>> experiencing the issue, is it possible for me to replace the relevant 
>> code/source file with what you have (or would that require recompiling)? 
>> Could this be an OS issue? I'm running Mac OSX 10.6.2.
>> 
>> By the way, I "replied all" on this message, but let me know if that is not 
>> the preferred convention. Cheers,
>
> Reply all. That way people can correct my mistakes and general cluelessness. 
> I'm running MacOSX 10.5.8 so it would seem less likely that is the 
> explanation.
>
> 1) Did you run the example in the help pages?
>
> 2) When I look at :
>
>>  methods(model.tables)
> [1] model.tables.aov*     model.tables.aovlist*
>
> ... I see both an "aov" method and an "aovlist" method. Is it possible that 
> there is something about the object that you are working on that makes it an 
> aovlist at thus invokes a different function than what the help page invokes?
>
> The code would not require complination... it's available with getAnywhere() 
> and I do not see any calls to compiled or .Internal subroutines. Tell me what 
> happens with the above questions first.
>
> -- 
> David
>
>> 
>> Jon
>
> David Winsemius, MD
> Heritage Laboratories
> West Hartford, CT
>
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>

Charles C. Berry                            (858) 534-2098
                                             Dept of Family/Preventive Medicine
E mailto:cberry at tajo.ucsd.edu	            UC San Diego
http://famprevmed.ucsd.edu/faculty/cberry/  La Jolla, San Diego 92093-0901