drcte (version 1.0.65)

compParmte: Comparison of parameters for time-to-event models

Description

Compare parameters from different assays, either by means of ratios or differences. It is only usable with parametric models

Usage

compParmte(object, strVal, operator = "/", robust = FALSE,
         units = NULL, display = TRUE)

Value

A matrix with columns containing the estimates, estimated standard errors, values of t-statistics and p-values for the null hypothesis that the ratio equals 1 or that the difference equals 0 (depending on the operator argument).

Arguments

object

an object of class 'drcte'

strVal

a name of parameter to compare.

operator

a character. If equal to "/" (default) parameter ratios are compared. If equal to "-" parameter differences are compared.

robust

Logical: if TRUE, robust sandwich standard errors are printed instead of the asymptotic formula. Defaults to TRUE if 'units' or 'type' is given.

units

Optional vector that identifies groups of subjects, used in computing a cluster robust standard error. Like model variables, this is searched for in the dataset pointed to by the data argument.

display

logical. If TRUE results are displayed. Otherwise they are not (useful in simulations).

Author

Andrea Onofri and Christian Ritz

Details

The function compares actual parameter estimates, and therefore the results depend on the parameterisation used.

Examples

data(lotus)
mod <- drmte(count ~ timeBef + timeAf, curveid = Stage,
                fct = loglogistic(), data = lotus,
             upperl = c(NA, 1, NA))
compParmte(mod, "d", robust = TRUE)