Try this:
dif <- na.omit(c(DF$STARTDATE[-1], NA) - DF$ENDDATE)
list(DF$ENDDATE[dif != 1] + 1, DF$ENDDATE[dif != 1] + (dif[dif != 1] - 1))
On Mon, Mar 28, 2011 at 8:56 AM, <angelo.lina...@bancaditalia.it> wrote:
> Good morning,
>
>
>
> I am facing a problem very easy to solve with a program, but not too
> easy (at least IMHO) with a "declarative" approach.
>
> I have a dataframe df with some information about bank branches with a
> validity time associated (start date/end date, format YYYY-MM-DD) to
> some attributes (for example number of employees assigned).
>
>
>
> The following example will clarify this description:
>
>
>
> BANK_ID BRANCH_ID EMPLOYEE # STARTDATE ENDDATE
>
> B1 A15 30 2001-01-01 2001-10-15
>
> B1 A15 28 2001-10-16 2001-12-31
>
> B1 A15 32 2002-01-01 2003-04-18
>
> B1 A15 33 2003-04-19 2004-12-31
>
> B1 A15 29 2005-03-01 2010-12-31
>
> B1 A15 30 2011-02-12 9999-12-31
>
> ........................................................................
> ........................................................................
> .....................
>
>
>
> I would like to find the "missing time intervals" ("holes" - in the
> example 2005-01-01 to 2005-02-28 and from 2011-01-01 to 2011-02-11).
>
> The "programmer's way" would be:
>
>
>
> * Sort the data by "key" + start date
>
> * For each occurrence add 1 day to end date and compare the
> result with the start date of the following occurrence
>
>
>
> Can someone help me in finding a "declarative" way to do it ?
>
>
>
> Thank you in advance
>
>
>
> Angelo Linardi
>
>
>
>
>
>
>
>
>
>
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--
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O
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