[R] How to set a filter during reading tables

[Linlin Yan]

I think you can use readLines(n=1) in loop to skip unwanted rows.

On Mon, Jun 1, 2009 at 12:56 AM,  <guox at ucalgary.ca> wrote:
> Thanks, Juliet.
> It works for filtering columns.
> I am also wondering if there is a way to filter rows.
> Thanks again.
> -james
>
>> One can use colClasses to set which columns get read in. For the
>> columns you don't
>> want you can set those to NULL. For example,
>>
>> cc <- c("NULL",rep("numeric",9))
>>
>> myData <-
>> read.table("myFile.txt",header=TRUE,colClasses=cc,nrow=numRows).
>>
>>
>> On Wed, May 27, 2009 at 12:27 PM,  <guox at ucalgary.ca> wrote:
>>> We are reading big tables, such as,
>>>
>>> Chemicals <-
>>> read.table('ftp://ftp.bls.gov/pub/time.series/wp/wp.data.7.Chemicals',header
>>> = TRUE, sep = '\t', as.is =T)
>>>
>>> I was wondering if it is possible to set a filter during loading so
>>> that
>>> we just load what we want not the whole table each time. Thanks,
>>>
>>> -james
>>>
>>> ______________________________________________
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>>> PLEASE do read the posting guide
>>> http://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.
>