On Wed, May 8, 2013 at 3:43 AM, avinash sahu <avinash.s...@gmail.com> wrote: > Hi All, > > I am struggling to parse a XML file that describes a tree. The XML file is > present here: > http://www.emouseatlas.org/emap/ema/theiler_stages/StageDefinition/Stage_xml/TS23.xml > I want is simple list of parents id of each component. The output will look > like > Component = [7148 7149 7150 7151..... 7177..............] > Parents= [NA 7148 7149 7150.... 7148..............] > I meant if components are arranged from 7148 to 8419, I need their parents > id. >
Try this: library(XML) URL <- "http://www.emouseatlas.org/emap/ema/theiler_stages/StageDefinition/Stage_xml/TS23.xml"; root <- xmlTreeParse(URL, useInternalNodes = TRUE) fn <- function(node) { id <- xmlAttrs(node)["id"] parent.id <- xmlAttrs(xmlParent(node))["id"] setNames(head(c(id, parent.id, NA), 2), c("id", "parent")) } parents <- t(xpathSApply(root, "//component", fn)) parents[1:4, ] The last line shows the first 4 child/parent pairs as follows: id parent [1,] "7148" NA [2,] "7149" "7148" [3,] "7150" "7149" [4,] "7151" "7150" -- Statistics & Software Consulting GKX Group, GKX Associates Inc. tel: 1-877-GKX-GROUP email: ggrothendieck at gmail.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.
