effectiveDistance {Rdistance}

Calculates the effective sampling distance for estimated detection functions

Description

Computes Effective Strip Width (ESW) for line-transect detection functions, or the analogous Effective Detection Radius (EDR) for point-transect detection functions.

Usage

effectiveDistance(obj, newdata = NULL)

Arguments

obj

An estimated detection function object. An estimated detection function object has class 'dfunc', and is usually produced by a call to dfuncEstim. The estimated detection function may optionally contain a g(0) component. If no g(0) component is found, g(0) = 1 is assumed.

newdata

A data frame containing new values of the covariates at which ESW's or EDR's are sought. If NULL or missing and obj contains covariates, the covariates stored in obj are used. See Value section.

Details

Serves as a wrapper for ESW and EDR.

Value

If newdata is not missing or NULL and covariates are present in obj, returned value is a vector with length equal to the number of rows in newdata. If newdata is missing or NULL and covariates are present in obj, returned value is a vector with length equal to the number of detections in obj$detections. In either of the above cases, elements in the returned vector are the effective sampling distances for the corresponding set of covariates.

If obj does not contain covariates, newdata is ignored and a scalar equal to the (constant) effective sampling distance for all detections is returned.

See Also

dfuncEstim ESW EDR