apa_add_agg_class

A <code>apa_list</code>-object that was created with the
[apa_list]-function.

apa_list

A vector of column names in <code>apa_list$tree_dat</code>
that specify variables that are used as additional grouping variable.

agg_class_column

logical, specifies if <code>POLYGON</code>s of APA-patches be
should be added.

apa_polygon

Additional grouping variables are added to an <code>apa_list</code> (for example
tree species information). All APA-properties will be aggregated for these
classes as well.

Maps of the 'area potentially available' (APA) of trees is calculated from
mapped forest stands using the approach from Gspaltl et al. (2012) <doi:10.1093/forestry/cps052>.
This is done by computing a rasterized version of
'weighted voronoi diagrams' using a an approximation of the trees competitive
ability (e.g., crown radius, leaf area) as weight. The main output are 'Raster*'-
objects from the 'raster' package that are stored together with the raw data in
apa_list's, the main class of the 'APAtree' package. Aggregation functions are
provided to calculate stand characteristics based on APA-maps such as relative
proportions according to APA-size and the neighborhood diversity index NDiv
(Glatthorn (2021) <doi:10.1016/j.ecolind.2021.108073>).

apa_add_agg_class: Add aggregation classes to an `apa_list`

Description

Usage

Arguments