Example of correlations of fixed effects

corr_fixedeff_example1.R

> (lm.full<-lmer(wear~material-1+(1|Subject), data = BHHshoes))
Linear mixed model fit by REML 
Formula: wear ~ material - 1 + (1 | Subject) 
   Data: BHHshoes 
  AIC  BIC logLik deviance REMLdev
 62.9 66.9  -27.5     53.8    54.9
Random effects:
 Groups   Name        Variance Std.Dev.
 Subject  (Intercept) 6.1009   2.470   
 Residual             0.0749   0.274   
Number of obs: 20, groups: Subject, 10

Fixed effects:
          Estimate Std. Error t value
materialA   10.630      0.786    13.5
materialB   11.040      0.786    14.1

Correlation of Fixed Effects:
          matrlA
materialB 0.988