This is the generic definition for generating objects of
class "sampSurf." There are several methods corresponding to this
generic that may be found in
sampSurf-methods. One of the
constructor methods in particular, averts the necessity for being
familiar with the other classes in the package and can simply be run
from scratch, requiring only an extant "
object on which to draw the sample and compute the surface. More
details and examples are found in "The sampSurf Class"
Signature object, which differs for each method.
Signature object of class "
The generation of objects of this class depends on the
signature of the method used. One common thread is that all methods
require an existing object of class "
one of its subclasses to be available. This will be the grid area over
which the population is to be simulated and sampling surface
determined. It is often convenient to set this area up to be equal to
one acre or one hectare. However, one could match each "tract" to the
size of a sample plot where logs or trees have been measured in the
field, for example. And there is no reason why the tract must be
restricted to a smaller size, except for the limitations of computer
memory. The raster package routines should help with this
because they will store large rasters (tracts) on disk, but I have not
had the chance to test this out sufficiently yet. In any case, one can
start from scratch and make all of the intervening objects necessary
to create a sampling surface with the appropriate constructor
method. Alternatively, one can bypass all the intermediate steps and
use the constructor that takes the number of individual stems and a
tract object, and let it do all of the work. These are both explained
in the vignette sited above and in the
A valid object of class "
Jeffrey H. Gove
"The sampSurf Class" vignette.
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