[R] XML package: modify info of internal node

Moreno Coco mcoco at staffmail.ed.ac.uk
Wed Feb 15 12:44:06 CET 2012

Dear All,

I have a very simple question to which I did not find any
answer online (apologize if it exists).
I have an XML file (attached) on which I just want
to modify the info of a node.
So, I load my xml file:

current =  xmlTreeParse(file, useInternalNodes=T)

and I want to change the information of:


to be, for example: 1-1.jpg (newname)

I do:

xmlValue( xpathApply( current, "/annotation/filename")[[1]] ) = newname

now, the crazy thing is that it does the change to the xml
but it also through the following error:

Error in xmlValue(xpathApply(current, "/annotation/filename")[[1]]) =  
newname : could not find function "xpathApply<-"

it seems that it works, but for a mysterious reason, it also
seems that it does not work.

Since I have to apply this change many times, and write
the resulting modified .xmls, the loop would stop as a
result of the error...

what am i missing here? is there any simpler way to do it?

thanks a lot for your kind help,


P.S. I also try:

xmlSApply(xpathApply( current, "/annotation/filename")[[1]], xmlValue)  
= newname

obtaining the same result.

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