[R] Extracting columns with specific string in their names

[Jay]

Sorry, my mistake. The thing is that the command return no results at
all. However, when I just tried a simpler version of this (I had no
capital letters or no spaces in the string), it worked fine. I cant
figure it out, I think it all boils down to the fact that I'm no
expert at regexp's...




On Aug 22, 5:53 pm, "R. Michael Weylandt" <michael.weyla... at gmail.com>
wrote:
> Can you say a little more about what you mean "it does not work"? I'd guess
> you have a regular expression mistake and are probably getting more columns
> than desired, but without an example, it's hard to be certain.
>
> Use dput() and head() to give a small cut-and-paste-able example.
>
> Michael
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> On Mon, Aug 22, 2011 at 10:33 AM, Jay <josip.2... at gmail.com> wrote:
> > Hi,
>
> > Let's say that I have a set of column names that begin with the string
> > "Xyz". How do I extract these specific columns? I tried to do the
> > following:
>
> > dataframe1[,grep("Xyz",colnames(dataframe1))]
>
> > But it does not work. What is wrong with my expression?
>
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