[R] if - else

[jim holtman]

try:

Start <- ifelse (DateFirstEven < DateSecondEvent,
(DateFirstEvent+DateSecondEvent)/2, DateFound)



On 7/25/07, James J. Roper <jjroper at gmail.com> wrote:
> Greetings,
>
> I have some confusion with the use of if - else.  Let's say I have a
> four variables as follows:
>
> Condition               DateFound          DateFirstEvent
> DateSecondEvent
> NA                        10Jan2000          NA                             NA
> 0                           05Jan2000          07Jan2000
>   10Jan2000
> 1                           07Jan2000          07Jan2000
>   08Jan2000
> 2                           09Jan2000          NA                             NA
>
> Now, what I need to do is make a new variable that is either the
> midpoint of the first and second event dates, or the date found (I
> will call Start).
>
> I tried an if - else condition as follows:
>
> Start <- if (DateFirstEven < DateSecondEvent)
> (DateFirstEvent+DateSecondEvent)/2 else DateFound
>
> I also tried
>
> Start <- if (any(DateFirstEven < DateSecondEvent))
> (DateFirstEvent+DateSecondEvent)/2 else DateFound
>
> Only the first half of the expression was ever evaluated.
>
> I hope I have not been to brief, and will certainly appreciate any help.
>
> Thanks,
>
> Jim
>
> --
> James J. Roper
> Population Dynamics and Conservation of
> Terrestrial Vertebrates
> Caixa Postal 19034
> 81531-990 Curitiba, Paraná, Brasil
> =======================================
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> =======================================
> Ecologia e Conservação na UFPR
> http://www.bio.ufpr.br/ecologia/
> ---
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>
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>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem you are trying to solve?