perpendicularDistanceIZ-class: Class '"perpendicularDistanceIZ"'

In sampSurf: Sampling Surface Simulation for Areal Sampling Methods

Description

This class holds the inclusion zone definition for the ‘perpendicular distance sampling’ method (Williams & Gove, 2003) for sampling down coarse woody debris.

Objects from the Class

Objects can be created by calls of the form new("perpendicularDistanceIZ", ...). However, this is not recommended because the objects are fairly complex. Instead, one can use the object constructor perpendicularDistanceIZ to create new objects.

Slots

Most of the slots are described in the superclasses (see below), please see their help pages for more information. This class adds a few slots to the "downLogIZ" class specification.

pds:

Object of class "perpendicularDistance": This supplies the information for the Kpds factor, etc. for establishing the inclusion zone.

izPerim:

Object of class "matrix": A matrix representation of the inclusion zone in homogeneous coordinates. This can be manipulated and plotted as desired for easy access to the inclusion zone where needed.

area:

Object of class "numeric": The exact area of the inclusion zone.

perimeter:

Object of class "SpatialPolygons": This is the inclusion zone perimeter as a “SpatialPolygons” object.

pgArea:

Object of class "numeric": This is the area of the inclusion zone as calculated from the polygon in the perimeter slot using the “SpatialPolygons” object. As such, it is an approximation of the true area of the inclusion zone, which is given in the area slot. This just enables us to see how close the graphic representation is to the real area, and adjust if necessary the number of points defining the inclusion area perimeter.

pdsType:

Object of class "character": Specifies the type of perpendicular distance sampling used with regard to the selection (i.e., probability proportional to...) of the log. It can be one of "volume", "surfaceArea" or "coverageArea". (See also .StemEnv$pdsTypes for legal types.)

Extends

Class "downLogIZ", directly.
Class "pdsIZNull", directly.
Class "InclusionZone", by class "downLogIZ", distance 2.

Methods

izGrid

signature(izObject = "perpendicularDistanceIZ", tract = "Tract"): “InclusionZoneGrid” constructor

perimeter

signature(object = "perpendicularDistanceIZ"): Return the object perimeter

plot

signature(x = "perpendicularDistanceIZ", y = "missing"): Plot the object

summary

signature(object = "perpendicularDistanceIZ"): Object summary

Author(s)

Jeffrey H. Gove

References

Williams, M. S. and Gove, J. H. 2003. Perpendicular distance sampling: an alternative method for sampling downed coarse woody debris. Canadian Journal of Forest Research 33:1564–1579.

See Also

downLogIZs container class

Examples

showClass("perpendicularDistanceIZ")

sampSurf documentation built on March 5, 2021, 5:06 p.m.