Em 11/7/2011 09:16, Gilson Sanchez escreveu:
Pessoal mais uma vez procuro ajuda de vc's, consegui ajustar um modelo com nls, mas agora o que quero saber como eu faço para estimar o coeficiente (R2) e ver se a equação ajustou corretamente. obrigado
Gilson, Veja esta 'thread' https://stat.ethz.ch/pipermail/r-help/2005-June/072898.html e em particular veja a citação: "There is a good reason that an nls model fit in R does not provide r-squared - r-squared doesn't make sense for a general nls model. One way of thinking of r-squared is as a comparison of the residual sum of squares for the fitted model to the residual sum of squares for a trivial model that consists of a constant only. You cannot guarantee that this is a comparison of nested models when dealing with an nls model. If the models aren't nested this comparison is not terribly meaningful. So the answer is that you probably don't want to do this in the first place." HTH,
-- MSc. Gilson Sánchez Chia
Laboratório de Fisiologia Vegetal
Embrapa Amazônia Ocidental
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