npsurv (version 0.4-0.1)

Deltamatrix: Delta matrix

Description

Deltamatrix computes the Delta matrix, along with maximal intersection intervals, for a set of intervals.

Usage

Deltamatrix(LR)

Arguments

LR

two-column matrix, each row of which stores an censoring interval of the form \((L_i, R_i]\). If \(L_i = R_i\), it is an exact observation.

Value

A list with components:

left

left endpoints of the maximal intersection intervals.

right

right endpoints of the maximal intersection intervals.

Delta

logical matrix, for the Delta matrix.

Details

An intersection interval is a nonempty intersection of any combination of the given intervals, and a maximal intersection interval is an intersection interval that contains no other intersection interval.

The Delta matrix is a matrix of indicators (TRUE or FALSE). The rows correspond to the given interval-censored observations, and the columns the maximal intersection intervals. A TRUE value of the (i,j)-th element means that the i-th observation covers the j-th maximal intersection interval, and a FALSE value means the opposite.

References

Wang, Y. (2008). Dimension-reduced nonparametric maximum likelihood computation for interval-censored data. Computational Statistics & Data Analysis, 52, 2388-2402.

See Also

icendata, idf.

Examples

# NOT RUN {
(x = cbind(1:5,1:5*3-2))
Deltamatrix(x)
# }