REAR {agce} | R Documentation |
This function fits two different models using the nlme library and then compares them using a likelihood ratio test. The first model is an autoregressive random errors model with a linear mean assuming different slope in each group. The second model is an autoregressive random errors model with a linear mean assuming same slope in each group.
REAR(data,time)
data |
The data matrix or data frame, where the first column correspond to the group id, the second to the animal id, the remaining columns are the measurement at each time. |
time |
A vector of numeric values corresponding to the time points at which the measurements were effectued. |
The data are reshaped in a longitudinal dataset and then the models are fit using the lme function of the nlme library.
Chi |
The value of the Chisquare test used to test the hypothesis of equal slopes |
df |
The degrees of freedom for the Chisquare test |
p |
The p-value associated to the Chisquare test |
sum.fit.full |
The summary on the fit of the full model |
std.fit.reduced |
The summary on the fit of the reduced model |
Raphael Gottardo
Daniel F. Heitjan, Andrea Manni and Richard J. Santen Statistical Analysis of in Vivo Tumor Growth Experiments Cancer Research 53:6042-6050, 1993.
data(Bt20) REAR(Bt20,c(0,3,7,10,14,16))