Figure 6.1 Modifying a circle grob R code	Figure 6.2 Editing grobs R code	Figure 6.3 The structure of a gtree R code	Figure 6.4 Editing a gtree R code
Figure 6.5 Using a gtree to group grobs R code	Figure 6.6 Packing grobs by hand R code	Figure 6.7 Calculating the size of a grob R code	Figure 6.8 Grob dimensions by reference R code
Figure 6.9 Editing the graphical context R code	Figure 6.10 Editing the grobs in a lattice plot R code