[R] Count based on 2 conditions [Beginner Question]

[Uwe Ligges]

On 16.09.2012 12:41, SirRon wrote:
> Hello,
> I'm working with a dataset that has 2 columns and 1000 entries. Column 1 has
> either value 0 or 1, column 2 has values between 0 and 10. I would like to
> count how often Column 1 has the value 1, while Column 2 has a value greater
> 5.
>
> This is my attempt, which works but doesn't seem to be very efficient,
> especially when testing different values or columns.
>
> count=0
> for (i in 1:1000) { if(dataset[i,2]>5 && ind[i,1]==1) { count=count+1}}

You probably want

count <- sum(dataset[,2]>5 & ind[,1]==1)

Uwe Ligges




>
> I'm looking for a more efficient/elegant way to do this!
>
> Thanks!
>
>
>
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