Compute the concordance

This is the working routine behind the concordance function. It is not meant to be called by users, but is available for other packages to use. Input arguments, for instance, are assumed to all be the correct length and type, and missing values are not allowed: the calling routine is responsible for these things.

Usage

concordancefit(y, x, strata, weights, ymin = NULL, ymax = NULL,
 timewt = c("n", "S", "S/G", "n/G2", "I"), cluster, influence =0,
 ranks = FALSE, reverse = FALSE, timefix = TRUE, keepstrata=10, 
 std.err = TRUE)

Arguments

y

the response. It can be numeric, factor, or a Surv object

x

the predictor, a numeric vector

strata

optional numeric vector that stratifies the data

weights

options vector of case weights

ymin, ymax

restrict the comparison to response values in this range

timewt

the time weighting to be used

cluster, influence,ranks, reverse, timefix

see the help for the concordance function

keepstrata

either TRUE, FALSE, or an integer value. Computations are always done within stratum, then added. If the total number of strata greater than keepstrata, or keepstrata=FALSE, those subtotals are not kept in the output.

std.err

compute the standard error; not doing so saves some compute time.

Details

This function is provided for those who want a “direct” call to the concordance calculations, without using the formula interface. A primary use has been other packages. The routine does minimal checking of its input arguments, under the assumption that this has already been taken care of by the calling routine.

Value

a list containing the results

Author

Terry Therneau

See also

concordance