[R] newbie question: grouping rows

[Matthew Scholz]

Hi all,

I have a very simple question that I can't seem to find the answer to.
How do I extract rows that meet a certain criteria  from a data frame
and group them into a new data frame? For example, if I want to make a
new data frame that only includes rows of data for which the p values
(given by one of the columns in the data frame) are less than a
certain value, how do I do this? It seems that there should be a
simple function that does this. I looked into getGroups from the nmle
package, but am not sure how to construct the form argument correctly
or even if it's the appropriate way to tackle this.

Thanks in advance of your answer,

Matt