[R] Operator > and <

Chuck Cleland ccleland at optonline.net
Wed Jul 25 14:45:39 CEST 2007


Yann Mauon wrote:
> Hello, 
> 
> I'am new to the R world and have a lot of question but the first is : How to
> deal with <> opertor in table objects? (Or how to deal with <> in
> general...) I explain my problem. 
> 
> I read a file with the read.table expression. I then obtain a matrix. I read
> the first line for example with the commande data[,1]. Then I would like to
> select only the element in this line that are greater than 2. Is there an
> elegant way to achieve that ?
> 
> Thanks by advance...

  Note that read.table() returns a data frame, not a matrix.  To subset,
try this:

subset(data, data[,1] > 2)

OR

subset(data, data[,1] > 2, select=1)

  Of course, it is always nice if each column in your data frame has a
meaningful name, so it can be referred to by name rather than number.

?subset
?names

-- 
Chuck Cleland, Ph.D.
NDRI, Inc.
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