[ferret_users] daily cumul to daily value

[Delclaux Francois <francois.delclaux@xxxxxxxxxxxxxxxxxxx>]

HI,
I have a file containing daily cumulative data. For exemple, if  pi is 
daily precipitation:
day 1:  p1
day 2 : p1 + p2
day 3 : p1+ p2 +p3
...
day i : p1 + p2 + ... + pi-1 + pi
...
day 365 : p1 + p2 + ... + p365    = yearly precipitation

Now, I would like to calculate pi the daily precipitation, i.e.
day 1 : p1
day 2 : p2
day 3 : p3
...
day i : pi
...
day 365: p365

So, for each day, I have to substract the pi-1 value to the pi value.
Is it possible to do that with Ferret ?

Thanks in advance for any help

--
Francois DELCLAUX
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UMR HydroSciences Montpellier
Universite Montpellier II - Place Eugene Bataillon
Case courrier MSE
34095  Montpellier Cedex 5      FRANCE
http://www.hydrosciences.org/
mailto: delclaux@xxxxxxxxxxxxxxxxxxx
Tel : (33) (0)4 67 14 90 11      Fax : (33) (0)4 67 14 47 74
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