R help - Mar 2012 - Random sample from a data frame where ID column values don't match the values in an ID column in a second data frame

Hello,

Let's say I've drawn a random sample (sample1.df) from a large data
frame
(main.df), and I want to create a second random sample (sample2.df) where
the values in its ID column *are not* in the equivalent ID column in the
first sample (sample1.df).  How would I go about doing this?

In other words:

The values in sample2.df$ID *are not found* in sample1.df$ID,  and both
samples are drawn from main.df.

Thanks in advance,
Matt Dubins

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On Mar 29, 2012, at 2:37 PM, inkhorn wrote:
> Hello,
>
> Let's say I've drawn a random sample () from a large data frame
> (main.df), and I want to create a second random sample (sample2.df)  
> where
> the values in its ID column *are not* in the equivalent ID column in  
> the
> first sample (sample1.df).  How would I go about doing this?
>
> In other words:
>
> The values in sample2.df$ID *are not found* in sample1.df$ID,  and  
> both
> samples are drawn from main.df.
>
?"%in%"

sample2.df <- main.df[ ! main.df[, "ID"] %in% sample1.df[,
"ID"] , ]

> Thanks in advance,
> Matt Dubins
>
> --
> View this message in context:
http://r.789695.n4.nabble.com/Random-sample-from-a-data-frame-where-ID-column-values-don-t-match-the-values-in-an-ID-column-in-a-se-tp4516448p4516448.html
> Sent from the R help mailing list archive at Nabble.com.
>
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