how to calculate "axis variance" in metaMDS, pakage vegan?
On 1/12/09 11:12 AM, "Gian Maria Niccol? Benucci" <gian.benucci at gmail.com> wrote:
Hi Hi there, I am trying to use funcion metaMDS (vegan pakage) for Community Ecology data, but I find no way to calculate the "expressed variance" of the first 2 axis? is there a way to do that? Thanks a lot in advance,
Gian, Why nobody asks how to calculate the non-linear stress of PCA or RDA? Non-linear stress would make just as little sense for PCA or RDA as the axis variance makes for NMDS. The axis variance is purely a measure of PCA family of methods (even CA family has a bit different measure), and there is no meaningful way of calculating "expressed variance" for NMDS axes (and indeed, a separate axis is not meaningful for NMDS: it is the configuration spanned by all axes together that makes sense). Cheers, Jari Oksanen