There is a dataframe named cnbd, for example:
dataframe
cnbd
cnbd = data.frame(1,2,3,NA,NA,5)
Thus the expression:
You can try the write.csv command:
write.csv(cnbd, file="cnbd.csv", na="")
Try this:
write.table(df, "cnbd.csv", na = "", row.names = FALSE, col.names = FALSE, append = TRUE, sep = ",")