survDabrowska {survSpearman}

Computes marginal and joint survival probability estimates using Dabrowska's method.

Description

The function computes marginal and joint survival probabilities for right-censored data using Dabrowska's (1988) method.

Usage

survDabrowska(X, Y, deltaX, deltaY)

Arguments

X

Time to event or censoring for variable X. It indicates time to event if argument deltaX is 1 and time to censoring if argument deltaX is 0.

Y

Time to event or censoring for variable Y. It indicates time to event if argument deltaY is 1 and time to censoring if argument deltaY is 0.

deltaX

Event indicator for variable X. deltaX is 1 if the event is observed and 0 if it is censored.

deltaY

Event indicator for variable Y. deltaY is 1 if the event is observed and 0 if it is censored.

Details

The function returns a list with two values: Dabrowska's estimator of the marginal and joint survival probabilities, DabrowskaEst, and its corresponding marginal and joint cumulative distribution functions (CDFs), DabrowskaCDF, based on the bivariate survival data provided by the user.

Value

A list of two elements: DabrowskaEst and DabrowskaCDF. DabrowskaEst is a matrix containing marginal and joint survival probabilities. The first column is the marginal survival probability corresponding to variable X. The first row is the marginal survival probability corresponding to variable Y. The rest of the matrix contains the joint survival probabilities. The row names of DabrowskaEst are ordered X-values. The column names of DabrowskaEst are ordered Y-values. Element DabrowskaEst[1,1] equals 1. Its row and column name is '0'. DabrowskaCDF is a matrix containing marginal and joint cumulative distribution functions (CDFs). The first row of DabrowskaCDF is the marginal CDF corresponding to variable X. The first column of DabrowskaCDF is the marginal CDF corresponding to variable Y. The row and column names of DabrowskaCDF are the same as for DabrowskaEst.

Author(s)

Svetlana K Eden, [e-mail]

References

Dabrowska, D. M. (1988). Kaplan–Meier estimate on the plane. The Annals of Statistics 16, 1475–1489.

Examples

X = c(0.5, 0.6, 0.6, 0.8)
Y = c(0.44, 0.77, 0.88, 0.99)
deltaX = c(1, 0, 1, 1)
deltaY = c(1, 1, 1, 1)
survDabrowska(X, Y, deltaX, deltaY)