[R] Question regarding to replace NA
Dear r-users, Basically, I have a data as follows, data S s1 s2 s3 s4 s5 prob obs num.strata 1 N N N N N N 0.108 32 NA 2 Y N N N N Y 0.0005292 16 NA 3 NNNYN N N N Y N 0.0005292 24 NA 4 NNNYY N N N Y Y 0.0259308 8 1 I want to replace NA by 0, when I tried the following command, I get som error message. data[is.na(data)]-0 Warning message: In `[-.factor`(`*tmp*`, thisvar, value = 0) : invalid factor level, NAs generated Anyone knows how to deal with this? Thanks, Kate [[alternative HTML version deleted]] __ 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.
Re: [R] Question regarding to replace NA
Hi Kate, is.na() does not work on entire data frames. You just need to specify the column, for example: data[is.na(data[, 8]), 8] - 0 if the NAs were in column 8. Best regards, Josh On Tue, Nov 9, 2010 at 9:33 AM, Kate Hsu yhsu.rh...@gmail.com wrote: Dear r-users, Basically, I have a data as follows, data S s1 s2 s3 s4 s5 prob obs num.strata 1 N N N N N N 0.108 32 NA 2 Y N N N N Y 0.0005292 16 NA 3 NNNYN N N N Y N 0.0005292 24 NA 4 NNNYY N N N Y Y 0.0259308 8 1 I want to replace NA by 0, when I tried the following command, I get som error message. data[is.na(data)]-0 Warning message: In `[-.factor`(`*tmp*`, thisvar, value = 0) : invalid factor level, NAs generated Anyone knows how to deal with this? Thanks, Kate [[alternative HTML version deleted]] __ 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.
Re: [R] Question regarding to replace NA
Kate - As the error message indicates, num.strata is a factor. This can occur when you're reading in data and R encounters a non-numeric value which was not specified in the na.strings= argument to read.table. To do what you want, you'll need to convert it to a character variable first: myvar = factor(c(NA,NA,NA,'1')) myvar[is.na(myvar)] = 0 Warning message: In `[-.factor`(`*tmp*`, is.na(myvar), value = 0) : invalid factor level, NAs generated myvar = as.character(myvar) myvar[is.na(myvar)] = 0 myvar [1] 0 0 0 1 If you want the variable to be treated as a numeric variable, you can use as.numeric: as.numeric(myvar) [1] 0 0 0 1 Hope this helps. - Phil Spector Statistical Computing Facility Department of Statistics UC Berkeley spec...@stat.berkeley.edu On Tue, 9 Nov 2010, Kate Hsu wrote: Dear r-users, Basically, I have a data as follows, data S s1 s2 s3 s4 s5 prob obs num.strata 1 N N N N N N 0.108 32 NA 2 Y N N N N Y 0.0005292 16 NA 3 NNNYN N N N Y N 0.0005292 24 NA 4 NNNYY N N N Y Y 0.0259308 8 1 I want to replace NA by 0, when I tried the following command, I get som error message. data[is.na(data)]-0 Warning message: In `[-.factor`(`*tmp*`, thisvar, value = 0) : invalid factor level, NAs generated Anyone knows how to deal with this? Thanks, Kate [[alternative HTML version deleted]] __ 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. __ 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.
Re: [R] Question regarding to replace NA
On Tue, Nov 9, 2010 at 9:39 AM, Joshua Wiley jwiley.ps...@gmail.com wrote: Hi Kate, is.na() does not work on entire data frames. whoops, I did not mean that. is.na() has a data frame method, but there are assignment issues (as you saw) when you use it that way. Josh [snip] __ 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.
Re: [R] Question regarding to replace NA
On Tue, Nov 9, 2010 at 9:43 AM, Joshua Wiley jwiley.ps...@gmail.com wrote: On Tue, Nov 9, 2010 at 9:39 AM, Joshua Wiley jwiley.ps...@gmail.com wrote: Hi Kate, is.na() does not work on entire data frames. whoops, I did not mean that. is.na() has a data frame method, but there are assignment issues (as you saw) when you use it that way. Last correction (I promise). Somehow I tested incorrectly which lead to me to my two erroneous statements before. is.na() works just fine with data frames. It was just the factor issue (as Phil said). x - data.frame(a = 1:3, b = c(1, 2, NA), d = c(NA, 2, 3), e = factor(c(NA, NA, 1))) x a b de 1 1 1 NA NA 2 2 2 2 NA 3 3 NA 31 x[is.na(x)] - 0 Warning message: In `[-.factor`(`*tmp*`, thisvar, value = 0) : invalid factor level, NAs generated x # other NAs removed, but not the factor ones a b de 1 1 1 0 NA 2 2 2 2 NA 3 3 0 31 off-to-hide-under-a-rock-Josh __ 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.
