[R] dataframe subset

[Duncan Murdoch]

On 2/8/2006 9:21 AM, Bernhard Baumgartner wrote:
> I have a dataframe with a column, say "x" consisting of values, each 
> value appearing different times, e.g.
> x: 1,1,1,1,2,2,4,4,4,9,10,10,10,10,10 ...
> and a vector, including e.g.:
> y: 2,9,10,...
> I need a subset of the dataframe: all rows where x is equal to one of 
> the values in y. Currently I use a loop for this, but because x and y 
> are large this is very slow. 
> Is there any idea how to solve this problem faster?

It's actually very easy.  Assume your dataframe is df, then

subset(df, x %in% y)

will give you what you want (assuming there is no column y in the 
dataframe).

Duncan Murdoch

> Thank you,
> Bernhard
> 
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