[R] How to use conditional statement

[Ivan Calandra]

Try with double "== "instead:
ifelse(val3 == "Monthly", val <- val1, val <- val2)

Single "=" is for setting arguments within a function call. If you want 
to test equality, then double "==" is required.
See ?"=="

HTH,
Ivan

Le 3/10/2011 11:45, Vincy Pyne a écrit :
> Dear R helpers
>
> Suppose
>
> val1 = c(10, 20, 35, 80, 12)
> val2 = c(3, 8, 11, 7)
>
> I want to select either val1 or val2 depending on value of third quantity val3.
>
> val3 assumes either of the values "Monthly" or "Yearly".
>
> If val3 = "Monthly", then val = val1 and if val3 = "Yearly", then val = val2.
>
> I tried the ifelse statement as
>
>
> ifelse(val3 = "Monthly", val = val1, val2)
>   
> I get following error
>
>> ifelse(val3 = "Monthly", val = val1, val2)
> Error in ifelse(val3 = "Monthly", val = val1, val2) :
>    unused argument(s) (val3 = "Monthly", val = val1)
>
>> val
> Error: object 'val' not found
>
> Kindly guide.
>
> Regards
>
> Vincy
>
>
>
> 	[[alternative HTML version deleted]]
>
>
>
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-- 
Ivan CALANDRA
PhD Student
University of Hamburg
Biozentrum Grindel und Zoologisches Museum
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+49(0)40 42838 6231
ivan.calandra at uni-hamburg.de

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