Or simply do :

position <- as.numeric(trend1 == trend2 )
position

2011/2/24 Dimitris Rizopoulos <d.rizopoulos@erasmusmc.nl>

> there are also vectorized logical operators; have a look at the help page
> ?'&', and try this:
>
>
> trend1 <- c(1,1,1,1,1,1,-1,-1,-1,-1,-1,-1)
> trend2 <- c(1,1,1,1,1,1,1,1,1,1,1,-1)
>
> position <- as.numeric((trend1 == 1 & trend2 == 1) | (trend1 == -1 & trend2
> == -1))
> position
>
>
> I hope it helps.
>
> Best,
> Dimitris
>
>
>
> On 2/24/2011 9:41 AM, Kushan Thakkar wrote:
>
>> I have two vectors: both have possible values of 1,-1, or 0
>>
>> trend1<- c(1,1,1,1,1,1,-1,-1,-1,-1,-1,-1)
>> trend2<- c(1,1,1,1,1,1,1,1,1,1,1,1,1,1,)
>>
>> i want to create a third vector that is conditional upon these two
>> vectors:
>>
>> if (trend2 == 1&&  trend1 == 1) {position<- 1}
>> elseif (trend2 == -1&&  trend1== -1) {position<- 1}
>> else {position<- 0}
>>
>> based on this two conditions, the position vector should have a value:
>>
>> position: 1,1,1,1,1,1,0,0,0,0,0,0
>>
>> Is there a way to do this in R without explicitly going through a for
>> loop?
>> The if condition doesn't work as it only accept one condition (aka no
>> vectors).
>>
>>        [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help@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.
>>
>>
> --
> Dimitris Rizopoulos
> Assistant Professor
> Department of Biostatistics
> Erasmus University Medical Center
>
> Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
> Tel: +31/(0)10/7043478
> Fax: +31/(0)10/7043014
> Web: http://www.erasmusmc.nl/biostatistiek/
>
>
> ______________________________________________
> R-help@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.
>



-- 
Kamel Gaanoun
(+33) (0)6.76.04.65.77

	[[alternative HTML version deleted]]

