[R] simple if question

[Thomas Levine]

Posting some sample data would help, but I think something like this
is what you want

data[data$school=='Cornell University',]

For example

CO2[CO2$Type=='Quebec',]

Tom

2011/3/26 Sebastián Daza <sebastian.daza at gmail.com>:
> Hi everyone,
> I have just got different samples from a dataframe (independent and
> exclusive, there aren't common elements among them). I want to create a
> variable that indicate the sampling selection of the elements in the
> original dataframe (for example, 0 = no selected, 1= sample 1, 2=sample 2,
> etc.).
>
> I have tried to do it with ifelse command, but the problem is that the
> second line replaces the values of the first line, and I haven't been able
> to do it with the if command (I got this error: In if (data$school %in%
> sample1) { :
>  the condition has length > 1 and only the first element will be used)
>
> data$selection <- ifelse(data$school %in% sample1, 1, 0)
> data$selection <- ifelse(data$school %in% sample2, 2, 0)
>
> Any ideas?
> Thank you in advance.
>
> --
> Sebastián Daza
> sebastian.daza at gmail.com
>
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