[R] if else in R

[Jeff Newmiller]

Which means you should use the ifelse function...

ab$c <- ifelse( ab$b>0, ab$a/ab$b, 0 )
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Sent from my phone. Please excuse my brevity.

Nick Matzke <matzke at berkeley.edu> wrote:
>Hi,
>
>This would be an issue with if() as well as if/else.  ab$b has 4
>numbers in it, so ab$b > 0 evaluates to "TRUE TRUE FALSE TRUE" or
>whatever. if() can only take a single true or false. Cheers! Nick
>
>On Tue, Nov 19, 2013 at 8:30 PM, Gary Dong <pdxgary163 at gmail.com>
>wrote:
>> Dear R users,
>>
>> I am a R beginner and I am having trouble in using "If Else" in R.
>Here is
>> an example:
>>
>> ## create a data frame
>>
>> a<-c(1,2,3,4)
>> b<-c(2,0,5,0)
>> ab<-data.frame(cbind(a,b))
>>
>> ##calculate c, which is the ratio between a and b
>>
>> if(ab$b>0) {
>>  ab$c<-ab$a/ab$b
>> } else {
>>  ab$c<-0
>>  }
>>
>> here is the error I got:
>>
>> Warning message:
>> In if (ab$b > 0) { :
>>   the condition has length > 1 and only the first element will be
>used.
>>
>> Any help is appreciated!
>>
>> Gary
>>
>>         [[alternative HTML version deleted]]
>>
>> ______________________________________________
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>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
>______________________________________________
>R-help at r-project.org mailing list
>https://stat.ethz.ch/mailman/listinfo/r-help
>PLEASE do read the posting guide
>http://www.R-project.org/posting-guide.html
>and provide commented, minimal, self-contained, reproducible code.