[R] extracting data from a dataframe

[Marc Schwartz]

> -----Original Message-----
> Hi everyone,
> 
> Here's a question about extracting data from a dataframe:
> 
> Let's say I've got a dataframe with two vectors, TEST and GENDER.
> GENDER
> contains a 1 for males and 2 for females. I want to separate the
results
> of TEST by GENDER so I can compare their means.
> 
> What's the most efficient way to do this with R?
> 
> -Tim

Presuming that you wish to perform a two-sample t-test on the means, you
don't need to actually "split" the dataframe. You could use the formula
method for t.test() by the following:

t.test(df$TEST ~ df$GENDER)

where df is the name of your dataframe.

If you actually want to split the dataframe, see ?split.

HTH.

Marc


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