first.well
, last.well
and
first.ill
are
expanded to multiple records; several for each interval where the
person is known to be well and one where the person is known to fail.
At the same time columns for the covariates needed to estimate rates
and the response variable are generated.expand.data(fu, formula, breaks, data)
first.well
, last.well
and
first.ill
in each row.fu
and formula
is interpreted.breaks
.formula
.Icens
fit.mult
fit.add