Using the umbrella alternative to merge certain entries to make
the sequence of ttot/deaths to increase then decrease or to decrease then increase.
Note that the pava function imposes non-decreasing or non-increasing order.
This function directly uses function pava().
Usage
umbrella(time_die,ttot,deaths,indi)
Arguments
time_die
a sequence of times where deaths happened.
ttot
the total time on test between each time point
and the previous time point (or 0).
deaths
the number of deaths at each time point.
indi
an indicator
indi == 0: monotonic failure rate (either decrease or increase)
indi == 1: denoting the failure rate increase then decrease
indi == 2: denoting the failure rate decrease then increase
Value
time2 == the merged time_die after the umbrealla alternative order restriction;
struct == a structure saves the partition information;
label == a note about how the failure rate varies;
indx == the position where the change point value is.