[R] problem with pattern matching

[Rnewbie]

the problem in my case is that some of the cells in dataframe$ID contain
multiple IDs, but in list$ID there is only one ID in each cell, so some of
the IDs cannot be matched if using the fucntion 'match' or '%in%'


jholtman wrote:
> 
> 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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>>
>> ______________________________________________
>> 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.
>>
> 
> 
> 
> -- 
> Jim Holtman
> Cincinnati, OH
> +1 513 646 9390
> 
> What is the problem that you are trying to solve?
> 
> ______________________________________________
> 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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