[R] delete data row

David Winsemius dwinsemius at comcast.net
Sat Oct 16 21:12:34 CEST 2010


IRD;

There is a danger in applying logical tests of equality to floating  
point numbers. It may be safer to use all.equal or zapsmall in the  
construction of your tests.

 > all.equal( (2^(0.5))^2 , 2)
[1] TRUE
 > (2^(0.5))^2 == 2
[1] FALSE


-- 
David.

On Oct 16, 2010, at 1:30 PM, Joshua Wiley wrote:

> Dear IRD,
>
> One way is to select every row except those where y = y.j and then
> assign that to IR.  In my example, which() returns a vector of the row
> numbers where the condition evaluated TRUE, then I used `-` to select
> not those rows.
>
> IR <- IR[-which(IR$y == y.j), ]
>
> HTH,
>
> Josh
>
> On Sat, Oct 16, 2010 at 5:02 AM, IRD <ird_ubru at hotmail.com> wrote:
>>
>>  Dear All
>> I have data like this:
>>> IR
>>      x        y
>> [1,] 5 2.865490
>> [2,] 3 1.454611
>> [3,] 3 2.258772
>> [4,] 6 1.476128
>> [5,] 4 2.771606
>>> y.j
>>       y
>> 2.865490
>>>
>> and I want to delete data row in IR where y = y.j
>> How I can do.
>> IRD
>>
>> ______________________________________________
>> 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.
>>
>
>
>
> -- 
> Joshua Wiley
> Ph.D. Student, Health Psychology
> University of California, Los Angeles
> http://www.joshuawiley.com/
>
> ______________________________________________
> 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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