[R] problem with pattern matching

[jim holtman]

I think you want to use either 'match' or '%in%'

x <- dataframe$ID %in% list$ID  # TRUE if it is in list

On Wed, Aug 5, 2009 at 5:36 AM, Rnewbie<xuancj at yahoo.com> wrote:
>
> I wanted to extract my interested rows from a dataframe. I used:
>
> grep(list$ID, dataframe$ID, value=T) #list contains a list of my interested
> IDs
>
> I got one match in return, which is the very first ID in list. It seems the
> matching process just stopped, once the first match was found.
>
>
>
> David Winsemius wrote:
>>
>>
>> On Aug 4, 2009, at 11:16 AM, Rnewbie wrote:
>>
>>>
>>> dear all,
>>>
>>> I got a problem with pattern matching using grep. I extracted a list
>>> of
>>> characters from a data frame, and I tried to match this list of
>>> characters
>>> to a column from another data frame. In return, I got only one
>>> match, but
>>> there should be far more matches. Any ideas what has gone wrong?
>>
>> In general this falls into the category of  a request to "read my
>> mind". One, out of probably an infinite number, of ways to get such a
>> result is to use if()  when you needed ifelse().
>>
>>>
>>> Another question, if I also want to match the whole of the elements
>>> against
>>> the non-initial parts of the elements in another table. Which
>>> command should
>>> I use?
>>
>> Cannot even assign a semantic meaning to that one. What is are "non-
>> initial parts of the elements of another table"?
>>
>>
>> ******************************************************************
>>>  .... provide commented, minimal, self-contained, reproducible code.
>> ******************************************************************
>>>
>>> Thanks
>>
>> David Winsemius, MD
>> Heritage Laboratories
>> West Hartford, CT
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>>
>
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>
> ______________________________________________
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>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?