On Tue, Apr 19, 2011 at 1:45 PM, Rolf Turner <rolf.tur...@xtra.co.nz> wrote: > On 19/04/11 21:39, Simone Gabbriellini wrote: >> >> Hello List, >> >> I have a data frame like: >> >> V130 V131 V132 V133 V134 V135 V136 >> 1 0 0 0.9 0 >> 0.9 0 0 >> 2 0 0 0 0 >> 0 0.8 >> 3 0 0 0 0 >> 0.9 0 0 >> 4 0.9 0 0 0 0 >> 0 0.9 >> 5 0 0 0 >> >> 6 0 0 0 0.9 0 >> 0 0.9 >> 7 0 0 0.8 0 0 >> 0 0 >> 8 0.9 0 0 >> 0.9 0.8 0 >> 9 0 0 0 0.9 >> 0.9 0 0 >> 10 0 0 0 0 0 >> 0 0.9 >> >> I would like to fill the empty cells with a 0... how to address those >> empty cells?
>From what the data frame looks like, you seem to have character values or factors there. (You could check it with sapply(DF, is) or just look at the Nth column separately: DF[,1].) If you need numeric values, you might want first convert them to numeric and then use is.na, otherwise, Dimitris Rizopoulos has offered a very general solution. /.../ Rolf Turner wrote: > In general, filling empty cells with zeros is ***very bad practice***. Zero > is not the same thing as ``missing''. So basically: Don't do this! I > don't care how badly you want to do it, or who told you to do it, just > ***don't***. But then again, consider that life, in general, is dangerous and ends with death. I know at least one real example where replacing NA's with zeros (with some caution) was just the right thing to do (respondents had to check 5 items in a list of 20, and in data entry, checked items were entered as 1's but the cells corresponding to unchecked items were left empty ... so I had to replace all NA's with 0's except in rows with nothing but NA's; there are probably many other legitimate examples). Best regards, Kenn Konstabel ______________________________________________ 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.