R help - May 2011 - denoting post-hoc test differences using letters

Is there code in R to automatically assign letters to different groups  
that are found to be statistically significant using a post-hoc test  
following an ANOVA? For example, let's say I found that relative rates  
of tree growth were statistically significant between tree species  
using an ANOVA and then I ran a TukeyHSD post-hoc test to determine  
which species were statistically different from one another. I can  
manually assign different letters for each species that is different  
from another, but is there code to do this automatically in R. I would  
like to add these letters to a table, but have many different ANOVAs  
and doing this manually will be quite time consuming.

Thanks,

Adrienne

Hi:

Perhaps the cld() function in the multcomp package is what you're looking
for.

Dennis

On Mon, May 23, 2011 at 9:40 AM, Adrienne Keller
<adrienne.keller at umontana.edu> wrote:
> Is there code in R to automatically assign letters to different groups that
> are found to be statistically significant using a post-hoc test following
an
> ANOVA? For example, let's say I found that relative rates of tree
growth
> were statistically significant between tree species using an ANOVA and then
> I ran a TukeyHSD post-hoc test to determine which species were
statistically
> different from one another. I can manually assign different letters for
each
> species that is different from another, but is there code to do this
> automatically in R. I would like to add these letters to a table, but have
> many different ANOVAs and doing this manually will be quite time consuming.
>
> Thanks,
>
> Adrienne
>
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