rcs_per {peRiodiCS}

Generate design matrix for periodic restricted cubic spline

Description

Generate design matrix for periodic restricted cubic spline.

Usage

rcs_per(x, knots = NULL, nk = 5, xmin = min(x, na.rm = TRUE),
  xmax = max(x, na.rm = TRUE))

Arguments

x

numerical x values to transform to new basis

knots

vector with locations of the knots of the spline

nk

number of knots, used only if the knots are not specified, overridden otherwise

xmin

value of the (theoretical) minimum of x

xmax

value of the (theoretical) maximum of x

#' @examples # load example data; see help("viral_east_mediteranean") data("viral_east_mediteranean")

# calculate location of knots to use Knots <- Hmisc::rcspline.eval(x = viral_east_mediteranean$EpiWeek, nk = 5, knots.only = TRUE)

# model viral infections vs weeks model <- glm(RSV ~ rcs_per(EpiWeek, knots = Knots), data = viral_east_mediteranean)

# plot model (with many points, to make it smooth) plot_per_mod(Model = model, XvarName = "EpiWeek", Smooth = TRUE)