T.Wunder wrote: > >>> Well, now I get a warning message like >>> "In xmlRoot.XMLInternalDocument(currentNodes[[1]]) : empty XML document" >>> >>> if I use this function. How could this be fixed? >>> >>> >> >> By telling use how you "used" that function. > > I'm sorry. I have a data frame df and typed > > convertToXML(df,"Tabelle") > >
If you use that function, you first get an error message that XML is unknown because you did not tell us that you used library(XML). It's the best guess here, but in many cases there are several libraries (pardon, Martin, packages) that do the same. Then it tells us that df is unknown, because you did not tell us what the data frame was. It could be a problem in your df, for example some unexpected data. So let's try a self-contained example with the iris data set available in all installations. It shows that everything works Ok, with the exception of the warning. By converting it to an error, your can locate the warning at the line xmlTree. The warning can be simply reproduced by library(XML) xmlTree("Dummy") Dieter library(XML) # or did you use a different package? convertToXML <- function(df,name) { xml <- xmlTree("Test") xml$addNode(name, close=FALSE) for (i in 1:nrow(df)) { xml$addNode("value", close=FALSE) for (j in names(df)) { xml$addNode(j, df[i, j]) } xml$closeTag() } xml$closeTag() return(xml) } data(iris) # these data are always there str(iris) tr = convertToXML(iris,"Tabelle") cat(saveXML(tr$value())) ## looks good options(warn=2) # to find where the warning occured cat(saveXML(tr$value())) ## looks good traceback() ## Looks like it is no problem of the function, because the following line # shows the same error xmlTree("Dummy") # Report it to Duncan R version 2.10.1 (2009-12-14) i386-pc-mingw32 locale: [1] LC_COLLATE=German_Germany.1252 LC_CTYPE=German_Germany.1252 [3] LC_MONETARY=German_Germany.1252 LC_NUMERIC=C [5] LC_TIME=German_Germany.1252 attached base packages: [1] stats graphics grDevices datasets utils methods base other attached packages: [1] XML_2.6-0 loaded via a namespace (and not attached): [1] tools_2.10.1 > -- View this message in context: http://n4.nabble.com/Convert-data-frame-to-XML-Tree-tp1478281p1478356.html Sent from the R help mailing list archive at Nabble.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.