[R] RegExp question

[David Winsemius]

Publicly produce something we can work with. I have no idea how to  
create an example that will match such an object.

?dput
?dump

Read Posting Guide.
-- 
David.

On Jun 16, 2010, at 12:54 PM, Andrej wrote:

> Thanks David for your fast reply, but now I realized tat "string" is
> of type:
>
>> class(string)
> [1] "jobjRef"
> attr(,"package")
> [1] "rJava"
>
> so I get an error when i try with gsub or sub:
>
>> sub("^.+\\t(\\d+)\\n.+$", "\\1", string)
> Error in as.character.default(x) :
>  no method for coercing this S4 class to a vector
>
> I think that there should be trivial solution, but... Any further
> idea?
>
> Regards, Andrej
>
>
>
> On Jun 16, 6:47 pm, David Winsemius <dwinsem... at comcast.net> wrote:
>> On Jun 16, 2010, at 12:04 PM, Andrej wrote:
>>
>>> Dear all,
>>
>>> I'm trying to filter out the "number of leaves" (it should be 1 in  
>>> the
>>> example below) from the following string:
>>
>>>> string
>>> [1] "Java-Object{J48 pruned tree\n------------------\n: 0  
>>> (15.0/3.0)\n
>>> \nNumber of Leaves  : \t1\n\nSize of the tree : \t1\n}"
>>
>>> Any idea how to do that as simple as possible? Thanks in advance for
>>> any advice.
>>
>> ?sub   # or ?gsub if you need more than one pattern matched (they are
>> on the same page).
>>
>> This should find the first occurrence of digits following a tab
>> terminated by a line feed and then return only the digits:
>>
>> string <- "Java-Object{J48 pruned tree\n------------------\n: 0
>> (15.0/3.0)\n \nNumber of Leaves  : \t1\n\nSize of the tree : \t1\n}"
>> sub("^.+\\t(\\d+)\\n.+$", "\\1", string)
>> [1] "1"
>>
>> The parens within the search pattern are matched to "\\1". Need to
>> double backslashed within patterns.
>>
>>
>>
>>> Regards, Andrej
>>
>> --
>>
>> David Winsemius, MD
>> West Hartford, CT
>>
>> ______________________________________________
>> R-h... at r-project.org mailing listhttps://stat.ethz.ch/mailman/ 
>> listinfo/r-help
>> PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> 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.

David Winsemius, MD
West Hartford, CT