[R] Deleting rows with special character

[Sarah Goslee]

Hi Peter,

On Fri, Nov 16, 2012 at 9:04 AM, Peter Kupfer <peter.kupfer at me.com> wrote:
> Dear all,
> maybe a simple problem but I found no solution for my problem.
> I have a matrix Y with 23 000 rows and 220 colums. The entries are "A", "B" or "C".

A reproducible example with sample data is helpful.

> I want to extract all rows (as a matrix ) of the matrix Y where all entries of a row are (for example) "A".

Really? Why not just make a new matrix with the right number of "A" values?

> Is there any solution? I tried the stringr- package but i doesn't work out.

Of course there is. Here's one option. But I'm not sure you've really
stated your actual problem. This extracts the rows where all values
are "A", and might at least get you started toward your real problem.

testdata <- matrix(c(
"A", "B", "C",
"B", "B", "B",
"C", "A", "A",
"A", "A", "A"),
ncol=3, byrow=TRUE)

testdata.A <- testdata[apply(testdata, 1, function(x)all(x == "A")), ,
drop=FALSE]



--
Sarah Goslee
http://www.functionaldiversity.org