I have parsed xml files in R environment and retrieved desired columns as below -

xmlfiles <- list.files(pattern = "*.xml")

input<-sapply(seq(xmlfiles), function(i){
doc <- xmlTreeParse(xmlfiles[i], useInternal = TRUE)

xpathSApply(doc, c('//phase', '//overall_status', '//primary_condition', '//nct_id', '//intervention_name', '//other_name', '//other_name.1', '//other_name.2', '//other_name.3', '//sponsors.lead_sponsor.agency'), xmlValue)
})

I want to write information fetched from xml files into a table/text but have been facing the following error-

write.table(input, file="output.txt", row.names=F, sep="\t")
Error in data.frame(c("NCT00752076", "Recruiting", "N/A", "cancer cell lines establishment",  :
arguments imply differing number of rows: 6, 4, 3, 5

Kindly need your inputs.