[R] problem subsetting data.frame in R version 2.15.2 for Windows

[Michael Weylandt]

On Mar 21, 2013, at 7:39, Pierrick Bruneau <pbruneau at gmail.com> wrote:

> Hi Borja,
> 
> You may issue:
> 
> attach(data)

No -- bad idea -- dangerous -- confusing statefulness, etc. (See explanations in the archives as to why)

> 
> which results in adding your column names to the search path of R for name
> resolving.
> 
> Pierrick Bruneau
> CRP Gabriel Lippmann
> 
> 
> On Wed, Mar 20, 2013 at 11:17 PM, Borja . <borjalatorre at outlook.com> wrote:
> 
>> Good day.
>> I create a data frame like this:
>>> data <- data.frame(a=1:10,b=11:20,c=21:30)
>> I can subset this data.frame by saying:
>>> data[data$a>7,]
>> and I get this result
>>                          a  b  c                    8   8 18 28
>>         9   9 19 29                  10 10 20 30
>> I understand I should get the same result by saying
>>> data[a>7,0]
>> but I don't. Instead I get:
>>                Error in `[.data.frame`(data, a > 7, 0) : object 'a' not

Try instead 

with(dat, dat[a > 0, ])

for a cleaner option. 

MW


>> found
>> Thank you very much in advance
>>        [[alternative HTML version deleted]]
>> 
>> ______________________________________________
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>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
> 
>    [[alternative HTML version deleted]]
> 
> ______________________________________________
> 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.