[R] Additional info: help with SMATR: help with pairwise comparisons using MA regression?

[Ioulia Bespalova]

Also, this works (taking out multcomp=TRUE, multcompmethod="adjusted"):

com.test=ma(Head.W1~Leg.3.1+Site, type="elevation", data=queens)
print(com.test)

....so for some reason it will do an MA regression on all my data
point together, but shows an error when I try to do pairwise
comparisons between groups.

Thank you,

Ioulia

--------

On Fri, May 11, 2012 at 2:09 AM, Ioulia Bespalova
<bespa20i at mtholyoke.edu> wrote:
> Hi there,
>
> I've been using the SMATR package to do standardized major axis (SMA)
> regression on allometric data, and I've been able to to pairwise
> comparisons of slope & elevation between multiple study sites.
>
> Now I'm trying to do the same thing using major axis (MA) regression,
> but I'm getting errors (SMATR should be able to do MA as well as SMA
> regression for everything, right?)
>
> I've attached the data file I'm using, the code looks like this:
>
> library(smatr)
>
> queens <- read.table("queens.txt", header=TRUE, sep="\t")
>
> # This works:
> com.test=sma(Head.W1~Leg.3.1+Site, type="elevation", data=queens,
> multcomp=TRUE, multcompmethod="adjusted")
> print(com.test)
>
> # This doesn't (all I did was change sma to ma, the package manual
> makes it seem that easy...):
> com.test=ma(Head.W1~Leg.3.1+Site, type="elevation", data=queens,
> multcomp=TRUE, multcompmethod="adjusted")
> print(com.test)
>
> This is the error I get when I try to do MA regression:
> Error in model.frame(formula = ..1, data = list(Site = c(2L, 2L, 2L, 2L,  :
>  'nthcdr' needs a list to CDR down
>
> Any idea as to why it won't work?
>
> Thank you for this resource!
>
> Ioulia