sorting & subsetting a data.frame
On Mar 6, 2011, at 7:34 PM, David Winsemius wrote:
On Mar 6, 2011, at 6:05 PM, Liviu Andronic wrote:
On Sun, Mar 6, 2011 at 11:53 PM, Liviu Andronic <landronimirc at gmail.com
wrote: On Sun, Mar 6, 2011 at 11:49 PM, Liviu Andronic <landronimirc at gmail.com
wrote: Dear all This may be obvious, but I cannot get it working. I'm trying to subset & sort a data frame in one go. x <- iris x$Species1 <- as.character(x$Species) ##subsetting alone works fine with(x, x[Sepal.Length==6.7,]) ##sorting alone works fine with(x, x[order(Sepal.Length, rev(sort(Species1))),]) ##gets subsetted, but not sorted as expected with(x, x[(Sepal.Length==6.7) & order(Sepal.Length, rev(sort(Species1))),]) ##gets subsetted, but sorts very strangely xa <- with(x, x[Sepal.Length==6.7,]); with(xa, xa[order(Sepal.Length, rev(sort(Species1))),]) xa <- with(x, x[Sepal.Length==6.7,]); with(xa, xa[order(rev(sort(Species1))),])
And of course I found the culprit after sending the e-mail: wrong call order. The following does what I want, although it's a bit messy: xa <- with(x, x[Sepal.Length==6.7,]); with(xa, xa[rev(order(sort(Species1))),]) xa <- subset(x, Sepal.Length==6.7); with(xa, xa[rev(order((sort(Species1)))),])
But it still doesn't work on my data! Any ideas for a different approach?
subset(x[order(x$Species1), ], Sepal.Length==6.7 ) Slight modification of the order/sort first subset second strategy: xa <- x[order(x$Species1), ][x$Sepal.Length==6.7, ]
If you really wanted to select cases first, and still keep it a one- liner there is the option of: (y <- x[x$Sepal.Length==6.7, ])[order(y$Species1), ]
Liviu
Regards Liviu
I've checked The R Inferno, Quick-R and several other places with no obvious solution. Any ideas? Regards Liviu -- 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
-- 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
-- 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
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David Winsemius, MD Heritage Laboratories West Hartford, CT
______________________________________________ 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.
David Winsemius, MD West Hartford, CT