# Re: [MORPHMET] pairwise matrix of vector angles in R

```Andrea,

If you already have the matrix of coefficients, geomorph has an internal
function that can do what you seek to do.  You can try this```
```
geomorph:::vec.ang.matrix(myMatrix, type = “r”) # for vector correlations
geomorph:::vec.ang.matrix(myMatrix, type = “deg”) # for vector angles in degrees

This function is an internal function for the advanced.procD.lm function, where
one could test the angular differences among the allometric vectors of taxa.
It assumes the matrix is arranges such that the rows are taxa vectors.  Please
note that if one uses advanced.procD.lm to perform this test, the matrix of
pairwise angles is available as part of the results.  We have an example for a
homogeneity of slopes test in the help file that should be analogous to your
example.  There are two ways to obtain the results

summary(HOS) # HOS is the test name; the pairwise angle matrix is part of the
summary
HOS\$obs.slopes.angles

Cheers!
Mike

> On Nov 3, 2017, at 4:38 AM, andrea cardini <alcard...@gmail.com> wrote:
>
> Dear All,
> please, does anyone know if there's an R package that, using a matrix with
> several vectors (e.g., coefficients for allometric regressions in different
> taxa), will compute the pairwise (all possible pairs of taxa) matrix of
> vector angles?
>
> Thanks in advance for any suggestion.
> Cheers
>
> Andrea
>
>
> --
>
> Dr. Andrea Cardini
> Researcher, Dipartimento di Scienze Chimiche e Geologiche, Università di
> Modena e Reggio Emilia, Via Campi, 103 - 41125 Modena - Italy
> tel. 0039 059 2058472
>
> Adjunct Associate Professor, School of Anatomy, Physiology and Human Biology,
> The University of Western Australia, 35 Stirling Highway, Crawley WA 6009,
> Australia
>
>
> FREE Yellow BOOK on Geometric Morphometrics:
> http://www.italian-journal-of-mammalogy.it/public/journals/3/issue_241_complete_100.pdf
>
> http://www.footprintnetwork.org/en/index.php/GFN/page/calculators/
>
> --
> MORPHMET may be accessed via its webpage at http://www.morphometrics.org
> --- You received this message because you are subscribed to the Google Groups
> "MORPHMET" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to morphmet+unsubscr...@morphometrics.org.
>

--
MORPHMET may be accessed via its webpage at http://www.morphometrics.org
---
You received this message because you are subscribed to the Google Groups
"MORPHMET" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to morphmet+unsubscr...@morphometrics.org.

```