WCEI {flexrsurv}

Weighted cumulative exposure index

Description

Generate the spline basis matrix for Weighted cumulative exposure index.

Usage

WCEI(x, 
    timevar, 
    fromT=0,
    Spline.WCEI=NULL, 
    Spline = c("m-spline", "b-spline", "tp-spline", "tpi-spline"), 
    Knots.t = NULL, 
    Degree.t = 3, 
    Intercept.t = TRUE,
    Boundary.knots.t = range(c(timevar, fromT)),
    Keep.duplicates.t = TRUE, 
    outer.ok = TRUE, 
    ...)

Arguments

x

the exposure variable.

timevar

the time variable.

fromT

Time at which starts exposure

Spline.WCEI

a S4 object with method deriv(), evaluate() and predict().

Spline

a character string specifying the type of spline basis. "b-spline" for B-spline basis, "tp-spline" for truncated power basis and "tpi-spline" for monotone (increasing) truncated power basis.

Knots.t

the internal breakpoints that define the spline used to estimate the WCEI effect. By default there are none.

Degree.t

degree of splines which are considered.

Intercept.t

a logical value indicating whether intercept/first basis of spline should be considered.

Boundary.knots.t

range of variable which is analysed.

Keep.duplicates.t

Should duplicate interior knots be kept or removed. Defaults is FALSE, which removes duplicate knots with a warning if duplicate interior knots are found.

outer.ok

logical indicating how are managed x values outside the knots. If FALSE, return NA, if TRUE, return 0 for the corresponding x values.

...

not used

Details

WCEI is based on package orthogonalsplinebasis

See Also

NLL NPH and NPHNLL.