Total inertia in package Vegan?
On Wed, 2010-11-17 at 13:23 +0100, Hedberg Peter wrote:
Dear all at the R-project help list. I have run into a problem when it comes to getting values for "total inertia" and "R-squared" for my DCA using "decorana" in the package "vegan". I have tried the "goodness" function, but the reply indicates that it does not work with "decorana" class objects. In Canoco one gets the Total inertia in the output together with 4 eigenvalues. In decorana one gets the 4 eigenvalues, but not the Total inertia. Is there a way for me to get the Total inertia without having to go over to Canoco?
OK, I might well be being incredibly stupid, but Total Inertia doesn't change with CA/DCA. Just run cca() on your matrix and grab the inertia. Whether you can compare the eigenvalues from decorana() and cca() I can't quite remember. Jari should be able to tell you - drop us a line on the Vegan R-Forge page: https://r-forge.r-project.org/forum/forum.php?forum_id=194&group_id=68 I'll take this opportunity to question why you are using DCA at all? G
Best regards, Petter Hedberg
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