Displaying 2 results from an estimated 2 matches for "soyfix".
2009 May 04
1
how to change nlme() contrast parametrization?
...]
(fm1Soy.lis <- nlsList(weight ~ SSlogis(Time, Asym, xmid, scal),
data = Soybean))
(fm1Soy.nlme <- nlme(fm1Soy.lis))
fm2Soy.nlme <- update(fm1Soy.nlme, weights = varPower())
plot(ranef(fm2Soy.nlme, augFrame = TRUE),
form = ~ Year * Variety, layout = c(3,1))
soyFix <- fixef(fm2Soy.nlme)
options(contrasts = c("contr.treatment", "contr.poly"))
(fm3Soy.nlme <-
update(fm2Soy.nlme,
fixed = Asym + xmid + scal ~ Year,
start = c(soyFix[1], 0, 0, soyFix[2], 0, 0, soyFix[3], 0, 0)))
# here I wouldn't like give the interc...
2004 Feb 20
1
nlme and multiple comparisons
This is only partly a question about R, as I am not quite sure about the
underlying statistical theory either.
I have fitted a non-linear mixed-effects model with nlme. In the fixed
part of the model I have a factor with three levels as explanatory
variable. I would like to use Tukey HSD or a similar test to test for
differences between these three levels.
I have two grouping factors: