Creates model formula list for multiple covariate distance sampling using
values supplied in call to ddf
mcds(
formula = NULL,
key = NULL,
adj.series = NULL,
adj.order = c(NULL),
adj.scale = "width",
adj.exp = FALSE,
shape.formula = ~1
)A formula list used to define the detection function model
string "mcds"
key function string
adjustment function string
adjustment function orders
adjustment function scale type
formula for scale function
formula for shape function
formula for scale function
string identifying key function (currently either "hn" (half-normal),"hr" (hazard-rate), "unif" (uniform) or "gamma" (gamma distribution)
string identifying adjustment functions cos (Cosine), herm (Hermite polynomials), poly (simple polynomials) or NULL
vector of order of adjustment terms to include
whether to scale the adjustment terms by "width" or "scale"
if TRUE uses exp(adj) for adjustment to keep f(x)>0
formula for shape function
Jeff Laake; Dave Miller