> Simon Blomberg wrote on 27/09/2010 08:10:
(Ted Garland had written:)
> >>Another interesting technical point. In general, PIC and PGLS are the
> >>same, especially if you stick with a simple Brownian motion model of
> >>character evolution. However, their complete mathematical identity
>
This one left my outbox too fast:
Emmanuel Paradis wrote on 27/09/2010 19:08:
> tr <- rtree(10)
>
Cannot be closer to the PIC model. And both models have the same number
of df (4 - 2 for the PICs; 5 - 3 for the GLS).
This should be... 9 - 2 for the PICs; 10 - 3 for the GLS (number of
point
Enrico Rezende wrote on 27/09/2010 18:26:
Hi everybody,
I am able replicate the results of independent contrasts and PGLS
employing R (mapping the intercept to the phylogenetic means). I also
recall comparing results of PDAP employing a star phylogeny against a
regular regression in SPSS for W
Hi everybody,
I am able replicate the results of independent contrasts and PGLS
employing R (mapping the intercept to the phylogenetic means). I also
recall comparing results of PDAP employing a star phylogeny against a
regular regression in SPSS for Windows. And as far as I can tell, this
app
Hi All,
Responding to two of Emmanuel's points.
>You can find in my book the R code to get exactly the same coefficients
>with PICs and PGLS. This works as long as the tree is ultrametric (for
>equal variance). It's not a formal proof, of course, but a strong suspicion.
You also get the same
Hi all,
Simon Blomberg wrote on 27/09/2010 08:10:
Hi Anne, Ted, Liam et al!,
On 25/09/10 02:51, tgarl...@ucr.edu wrote:
Hi Anne,
I am going to put this back online so others might benefit or chime in.
If you literally want to do correlations, then phylogenetically
independent contrasts may
