[ferret_users] how to find cumulative sum

[simon EK <simonambat@xxxxxxxxx>]

hi all,

I use the following script to list the rainfall
=========================================================
use rf_2000_2014.nc
let rf = rainfall[X=66E:101E@ave,Y=6N:39N@ave,t=1-jan-2000:31-dec-2000]
list rf
=========================================================

I would like to do the following:

1. create a cumulative total of rf (means 2nd day rf should be total of day1 & day2.

    3rd day total should be total of day1, day2 & day3. ...

2. I would like to know the date on which the cum. rf has crossed 50% of the total rf.

    (Eg. cum. rf of year 1951 is: 1029.86mm.

           50% of cum rf is : 514.93mm

            Date on which the cum rf crossed 50% rf : July 26, 1951)

how to do it using ferret prorammatically?

thanks in advance for the responses.

Regards

Simon