survregDtest Verify a survreg distribution

Description

This routine is called by survreg to verify that a distribution object is valid.

Usage

survregDtest(dlist, verbose = F)

Arguments

dlist	the list describing a survival distribution
verbose	return a simple TRUE/FALSE from the test for validity (the default), or a verbose description of any flaws.

Details

If the survreg function rejects your user-supplied distribution as invalid, this routine will tell you why it did so.

Value

TRUE if the distribution object passes the tests, and either FALSE or a vector of character strings if not.

Author(s)

Terry Therneau

See Also

survreg.distributions, survreg

Examples

# An invalid distribution (it should have "init =" on line 2)
#  surveg would give an error message
mycauchy <- list(name='Cauchy',
                 init<- function(x, weights, ...) 
                      c(median(x), mad(x)),
                 density= function(x, parms) {
                      temp <- 1/(1 + x^2)
                      cbind(.5 + atan(temp)/pi, .5+ atan(-temp)/pi,
                            temp/pi, -2 *x*temp, 2*temp^2*(4*x^2*temp -1))
                      },
                 quantile= function(p, parms) tan((p-.5)*pi),
                 deviance= function(...) stop('deviance residuals not defined')
                 )

survregDtest(mycauchy, TRUE)