A local polynomial model.

Refers to section 7.1. and 7.2.

Usage

lp_model(
  age,
  pos = NULL,
  tot = NULL,
  status = NULL,
  kern = "tcub",
  nn = 0,
  h = 0,
  deg = 2
)

Arguments

age

the age vector.

pos

the positive count vector (optional if status is provided).

tot

the total count vector (optional if status is provided).

status

the serostatus vector (optional if pos & tot are provided).

kern

Weight function, default = "tcub". Other choices are "rect", "trwt", "tria", "epan", "bisq" and "gauss". Choices may be restricted when derivatives are required; e.g. for confidence bands and some bandwidth selectors.

nn

Nearest neighbor component of the smoothing parameter. Default value is 0.7, unless either h is provided, in which case the default is 0.

h

The constant component of the smoothing parameter. Default: 0.

deg

Degree of polynomial to use. Default: 2.

Value

a list of class lp_model with 6 items

datatype

type of datatype used for model fitting (aggregated or linelisting)

df

the dataframe used for fitting the model

pi

fitted locfit object for pi

eta

fitted locfit object for eta

sp

seroprevalence

foi

force of infection

See also

[locfit::locfit()] for more information on the fitted locfit object

Examples

df <- mumps_uk_1986_1987
model <- lp_model(
  df$age, pos = df$pos, tot = df$tot,
  nn=0.7, kern="tcub"
  )
plot(model)