Consider the output for the inroductory "Rail" example in "Mixed
Effects
Models in S and S-PLUS" by Pinheiro and Bates:
> summary(fm1Rail.lme)
Linear mixed-effects model fit by REML
Data: Rail
AIC BIC logLik
128.177 130.6766 -61.0885
Random effects:
Formula: ~1 | Rail
(Intercept) Residual
StdDev: 24.80547 4.020779
Fixed effects: travel ~ 1
Value Std.Error DF t-value p-value
(Intercept) 66.5 10.17104 12 6.538173 0
Standardized Within-Group Residuals:
Min Q1 Med Q3 Max
-1.61882658 -0.28217671 0.03569328 0.21955784 1.61437744
Number of Observations: 18
Number of Groups: 6
I want to extract the variance components sigma = 4.020779 (the within
component) and sigma_b = 24.80547 (the between component).
I can get sigma easily:
sigma <- fm1Rail.lme$sigma
but how can I get sigma_b ?
Cheers, Murray Jorgensen
--
Dr Murray Jorgensen http://www.stats.waikato.ac.nz/Staff/maj.html
Department of Statistics, University of Waikato, Hamilton, New Zealand
Email: maj at waikato.ac.nz Fax 7 838 4155
Phone +64 7 838 4773 wk Home +64 7 825 0441 Mobile 021 1395 862
v <- VarCorr(fm1Rail.lme) str(v) # get an idea of how v is structured. This suggests: > as.numeric(v[1, 2]) [1] 24.80547 There may be easier and better ways.... HTH, Simon. At 11:02 AM 3/11/2005, you wrote:>Consider the output for the inroductory "Rail" example in "Mixed Effects >Models in S and S-PLUS" by Pinheiro and Bates: > > > summary(fm1Rail.lme) >Linear mixed-effects model fit by REML > Data: Rail > AIC BIC logLik > 128.177 130.6766 -61.0885 > >Random effects: > Formula: ~1 | Rail > (Intercept) Residual >StdDev: 24.80547 4.020779 > >Fixed effects: travel ~ 1 > Value Std.Error DF t-value p-value >(Intercept) 66.5 10.17104 12 6.538173 0 > >Standardized Within-Group Residuals: > Min Q1 Med Q3 Max >-1.61882658 -0.28217671 0.03569328 0.21955784 1.61437744 > >Number of Observations: 18 >Number of Groups: 6 > > >I want to extract the variance components sigma = 4.020779 (the within >component) and sigma_b = 24.80547 (the between component). > >I can get sigma easily: >sigma <- fm1Rail.lme$sigma > >but how can I get sigma_b ? > >Cheers, Murray Jorgensen > >-- >Dr Murray Jorgensen http://www.stats.waikato.ac.nz/Staff/maj.html >Department of Statistics, University of Waikato, Hamilton, New Zealand >Email: maj at waikato.ac.nz Fax 7 838 4155 >Phone +64 7 838 4773 wk Home +64 7 825 0441 Mobile 021 1395 862 > >______________________________________________ >R-help at stat.math.ethz.ch mailing list >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Woops! I should have written: as.numeric(VarCorr(fm1Rail.lme)[1,2]) for the "within" component. -- Dr Murray Jorgensen http://www.stats.waikato.ac.nz/Staff/maj.html Department of Statistics, University of Waikato, Hamilton, New Zealand Email: maj at waikato.ac.nz Fax 7 838 4155 Phone +64 7 838 4773 wk Home +64 7 825 0441 Mobile 021 1395 862