Using write.xlsx to replace an existing sheet with R package xlsx

Question

I am using package xlsx Version:0.5.7 Date: 2014-08-01. in R version 3.0.1 (2013-05-16) -- "Good Sport" Platform: i386-w64-mingw32/i386 (32-bit).

I have an xlsx file with at least 2 sheets (say A and B). I need to read data from A, edit them and save them in B. This has to be done on a periodical base.

I am able to read data from A with read.xlsx. After editing the data frame I want to save it in an existing sheet B in the same xlsx file.

I try with this line

write.xlsx(down, paste0(root,'/registration reports/registration complete_WK.xlsx'), sheet="data_final", col.names=T, row.names=F, append=T, showNA=F)

but it give me this error:

Error in `.jcall(wb, "Lorg/apache/poi/ss/usermodel/Sheet;", "createSheet", ` : 
  java.lang.IllegalArgumentException: The workbook already contains a sheet of this name

I need to replace that existing sheet multiple times. How can I do that?

Answer 1

If you want to save your new dataframe in an existing excel file, you first have to load the xlsx-file:

wb <- loadWorkbook(file)

which sheets you have you'll get like this:

sheets <- getSheets(wb)

you can easily remove and add (and thus replace) sheets with:

removeSheet(wb, sheetName="Sheet1")
yourSheet <- createSheet(wb, sheetName="Sheet1")

than you can fill the sheets with dataframes:

addDataFrame(yourDataFrame, yourSheet, <options>)
addDataFrame(anotherDataFrame, yourSheet, startRow=nrow(yourDataFrame)+2)

and last step is saving the whole workbook as .xlsx:

saveWorkbook(wb, file)

btw: the documentation of the xlsx-package is really good and helpful on such questions :) http://cran.r-project.org/web/packages/xlsx/xlsx.pdf