[R] About the error of the expentancy of life

[Juan Pablo Sánchez]

Dear R users:
I am looking for information on how to compute the error in an estimation of the expentancy of life using survival analysis methods. I am interesting either in the theoretical calculations or in the way to carry out the analysis using R. I know that the mean life can be computed in R using the function cph from the Design package, but what about the error of this estimation.

Cheers,
Juan Pablo.