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.
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