Jim and David, I certainly agree with your suggestions. How would you implement all.equal()? Since it compares entire objects (and the OP's goal is to remove any rows that equal some value), the only option I saw was to use *apply or a loop. zapsmall() is easier, (though it seems potentially slow if the data frame is very large). A toy example with some attempts I made follow:
x <- c(1, 2, 3, 5, 2, 3, 1) y <- 2 # Using calling all.equal on each element of x x[-which(as.logical(sapply(x, all.equal, current = y)))] # A crude introduction of tolerance x[-which(x <= y + .00001 & x >= y - .00001)] # Using zapsmall x[-which(zapsmall(x) == zapsmall(y))] Cheers, Josh On Sat, Oct 16, 2010 at 12:12 PM, David Winsemius <dwinsem...@comcast.net> wrote: > > 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_u...@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@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@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@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.
