downLog-class: Class "downLog": Representation of Downed Logs

In sampSurf: Sampling Surface Simulation for Areal Sampling Methods

Description

A subclass of virtual class “Stem” that can be used to represent downed coarse woody debris in the form of something resembling a log. The class provides for creation and graphical display of “downLog” objects.

Detail examples and information concerning this class is found in “The Stem Class” vignette, which should be consulted for more details on creating and using objects from this class.

Objects from the Class

Objects can be created by calls of the form new("downLog", ...). However, this is not recommended. The object has a number of required slots that can be somewhat complex to calculate. Therefore, a constructor function downLog has been provided that will make the desired object with the correct values for the slots. It is strongly recommended that one use this generic's methods to create the log objects.

Slots

Please note that all diameters below are presumed to be in the same units as length, i.e., meters for “metric”, and feet for “English” units.

In addition to the slots provided by the virtual superclass “Stem”, the following slots are represented...

buttDiam:

Object of class "numeric": the log diameter at the large (butt) end in the proper units.

topDiam:

Object of class "numeric": The small-end diameter of the log.

logLen:

Object of class "numeric": The log length in meters or feet.

logAngle:

Object of class "numeric": An angle for the log's position established from the center of the log relative to its "needle." The center of the log is equidistant from both ends along the established needle. On a straight log, the needle would correspond to the pith if everything were perfect.

solidType:

Object of class "numericNULL": The form parameter in the simple taper and volume equation presented in Van Deusen (1990) and Gove and Van Deusen (2011).

logVol:

Object of class "numeric": The log's volume.

surfaceArea:

Object of class "numeric": Total log surface area in the appropriate units.

coverageArea:

Object of class "numeric": Total log coverage area in the appropriate units.

biomass:

Object of class "numeric": Total log biomass. This will be NA if no conversion was specified at object creation.

carbon:

Object of class "numeric": Total log carbon content. This will be NA if no conversion was specified at object creation.

conversions:

Object of class "numeric": A vector with names c('volumeToWeight','weightToCarbon') specifying the conversion factors for woody biomass and carbon content.

taper:

Object of class "data.frame": The log's taper, either as specified from measurements, or as generated via downLog.

profile:

Object of class "data.frame": The log profile as generated from the taper. The log is assumed to be oriented with the small-end North, and the base at the origin.

rotLog:

Object of class "matrix": A rotated and translated version of profile using logAngle and location fields.

spLog:

Object of class "SpatialPolygons": A SpatialPolygons representation of rotLog via the sp package.

slNeedleAxis:

Object of class "SpatialLines": A fully transformed (rotated and translated) representation of the needle for the log as a SpatialLines object from package sp.

Extends

Class "Stem", directly.

Methods

bbox

signature(obj = "downLog"): Returns the bounding box for the object.

chainSawIZ

signature(downLog = "downLog", plotRadius = "numeric"): Chainsaw method inclusion zone constructor.

plot

signature(x = "downLog", y = "missing"): Graphically display a "downLog" object.

sausageIZ

signature(downLog = "downLog", plotRadius = "numeric"): Sausage sampling inclusion zone constructor.

standUpIZ

signature(downLog = "downLog", plotRadius = "numeric"): Stand-up method inclusion zone constructor.

summary

signature(object = "downLog"): Summary of the object.

Author(s)

Jeffrey H. Gove

References

Gove, J. H., Williams, M. S., Stahl, G. and Ducey, M. J. 2005. Critical point relascope sampling for unbiased volume estimation of downed coarse woody debris. Forestry 78:417–431.
Gove, J. H. and Van Deusen, P. C. 2011. On fixed-area plot sampling for downed coarse woody debris. Forestry Forestry 84:109–117.
Van Deusen, P.C. 1990. Critical height versus importance sampling for log volume: does critical height prevail? Forest Science
36(4):930–938.

See Also

"Stem", "standingTree", "StemContainer"

Examples

showClass("downLog")

sampSurf documentation built on March 5, 2021, 3:01 p.m.