ivmte (version 1.1.0)

uSplineInt: Integrated splines

Description

This function integrates out splines that the user specifies when declaring the MTRs. This is to be used when generating the gamma moments.

Usage

uSplineInt(x, knots, degree = 0, intercept = TRUE)

Arguments

x

the points to evaluate the integral of the the splines.

knots

the knots of the spline.

degree

the degree of the spline; default is set to 0 (constant splines).

intercept

boolean, set to TRUE if intercept term is to be included (i.e. an additional basis such that the sum of the splines at every point in x is equal to 1).

Value

a matrix, the values of the integrated splines. Each row corresponds to a value of x; each column corresponds to a basis defined by the degrees and knots.

Examples

# NOT RUN {
## Since the splines are declared as part of the MTR, you will need
## to have parsed out the spline command. Thus, this command will be
## called via eval(parse(text = .)). In the examples below, the
## commands are parsed from the object \code{splineslist} generated
## by \code{\link[MST]{removeSplines}}. The names of the elements in
## the list are the spline commands, and the elements themselves are
## the terms that interact with the splines.

## Declare MTR function
m0 = ~ x1 + x1 : uSpline(degree = 2,
                          knots = c(0.2, 0.4)) +
    x2 : uSpline(degree = 2,
                  knots = c(0.2, 0.4)) +
    x1 : x2 : uSpline(degree = 2,
                       knots = c(0.2, 0.4)) +
    uSpline(degree = 3,
             knots = c(0.2, 0.4),
             intercept = FALSE)

## Separate the spline components from the MTR function
splineslist <- removeSplines(m0)$splineslist

## Delcare the points at which we wish to evaluate the integrals
x <- seq(0, 1, 0.2)

## Evaluate the splines integrals
eval(parse(text = gsub("uSpline\\(",
                       "ivmte:::uSplineInt(x = x, ",
                       names(splineslist)[1])))


eval(parse(text = gsub("uSpline\\(",
                       "ivmte:::uSplineInt(x = x, ",
                       names(splineslist)[2])))
# }