Nonlinearity
require(car)
# Evaluate Nonlinearity
# component + residual plot
crPlots(fit)
# Ceres plots
ceresPlots(fit)
# Non-independence of Errors
# Test for Autocorrelated Errors
durbinWatsonTest(fit)## lag Autocorrelation D-W Statistic p-value
## 1 0.1692325 1.57513 0.194
## Alternative hypothesis: rho != 0