
324 Spatial Point Patterns: Methodology and Applications with R
OPERATOR EXAMPLE MEANING
+ +A inclu de this term
- -A rem ove this term
: A:B inclu de inte raction between A and B
* A*B inclu de these terms and their interaction
^ (A+B)^3 include th ese terms and interactions up to order 3
/ A/B nesting: B nested within A
%in% A %in% B interaction between A and B
| A|B conditioning: A given B
Table 9.2. Operators in model formulae. (The operator ‘|’ is only recognised by some functions.)
For the Beilschmiedia data, we have already looked at an additive model involving the terrain
elevation elev and terrain slope grad. Fitting a model with interaction