create.ddfobj: Create detection function object

In mrds: Mark-Recapture Distance Sampling

Create detection function object

Description

Creates and populates a specific list structure to define a detection function object and its data. The ddfobj is used throughout the package as a calling argument to various functions.

Usage

create.ddfobj(model, xmat, meta.data, initial)

Arguments

model	model list with key function and possibly adjustment functions, scale formula, and shape formula
xmat	model data frame
meta.data	list of options describing data like width, etc
initial	named list of initial values for parameters of the detection function (should have at least "scale", maybe also have "shape" and "adjustments")

Value

Distance sampling function object list with elements that all can be null except type:

type	type of detection function hn, hr, gamma, unif, logistic
xmat	model data frame
intercept.only	TRUE if scale = ~1 and any shape formula =~1
scale	sublist with elements (can be NULL i.e., unif key):formula, parameters, design matrix (dm)
shape	sublist with elements (power of hazard rate or gamma) (can be NULL i.e., unif or hn key):formula, parameters, design matrix (dm)
adjustment	sublist with elements (is NULL if no adjustments used):series,order,scale,parameters
g0	sublist with elements (not used at present):formula,parameters, design matrix(dm), link

Note

Internal function not meant to be called by user

Author(s)

Jeff Laake

See Also

detfct, ddf

mrds documentation built on Aug. 8, 2025, 6:39 p.m.