On Mon, Jul 22, 2013 at 11:37 AM, Prof Brian Ripley <rip...@stats.ox.ac.uk> wrote: > This really only makes sense for a list of logical vectors of the same > length. And by 'union' you seem to mean 'or'. > Indeed.
> Two approaches > > 1) Make a logical matrix and use apply(m, 1, any) > Of course! I tried apply(m, 1, "|") without luck, but I should have used apply(m, 1, any) instead. Thank you, Liviu > 2) Use Reduce(`|`, z) > > >> >> Consider the following: >> x <- head(iris) >> x[,c(2,4)] <- NA >> x[c(2,4),] <- NA >> # > x >> # Sepal.Length Sepal.Width Petal.Length Petal.Width Species >> # 1 5.1 NA 1.4 NA setosa >> # 2 NA NA NA NA <NA> >> # 3 4.7 NA 1.3 NA setosa >> # 4 NA NA NA NA <NA> >> # 5 5.0 NA 1.4 NA setosa >> # 6 5.4 NA 1.7 NA setosa >> z <- data.frame(!is.na(x)) >> # > z >> # Sepal.Length Sepal.Width Petal.Length Petal.Width Species >> # 1 TRUE FALSE TRUE FALSE TRUE >> # 2 FALSE FALSE FALSE FALSE FALSE >> # 3 TRUE FALSE TRUE FALSE TRUE >> # 4 FALSE FALSE FALSE FALSE FALSE >> # 5 TRUE FALSE TRUE FALSE TRUE >> # 6 TRUE FALSE TRUE FALSE TRUE >> >> I did find a solution, but it seems more like a hack: >>> >>> ##union of logical values by rows (union of list of logical values) >>> as.logical(rowSums(z)) >> >> [1] TRUE FALSE TRUE FALSE TRUE TRUE >>> >>> ##union of logical values by columns >>> as.logical(colSums(z)) >> >> [1] TRUE FALSE TRUE FALSE TRUE >> >> Another unusable monstrosity is as follows: >>> >>> ##union of list of logical values >>> z[[1]] | z[[2]] | z[[3]] | z[[4]] | z[[5]] >> >> [1] TRUE FALSE TRUE FALSE TRUE TRUE >> >> Is there a more elegant way to approach this problem and obtain the >> above logical vectors? Regards, >> Liviu >> >> > > > -- > Brian D. Ripley, rip...@stats.ox.ac.uk > Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ > University of Oxford, Tel: +44 1865 272861 (self) > 1 South Parks Road, +44 1865 272866 (PA) > Oxford OX1 3TG, UK Fax: +44 1865 272595 -- Do you know how to read? http://www.alienetworks.com/srtest.cfm http://goodies.xfce.org/projects/applications/xfce4-dict#speed-reader Do you know how to write? http://garbl.home.comcast.net/~garbl/stylemanual/e.htm#e-mail ______________________________________________ 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.
