comparing excel sheets in R - r

Question

I have two excel files with multiple sheets. The sheet names and their corresponding column names are same of both the files. Only the values in the sheets will differ. I want to compare using R which values are different and want to mark those cells

Answer 1

For the fun of it, here's a quick&dirty example on which you can build up for your specific needs:
wbsCreate <- function(v) {
wb <- createWorkbook()
sheet <- createSheet(wb, "Sheet1")
rows <- createRow(sheet, rowIndex=1:5)
cells <- createCell(rows, colIndex=1:5)
for (r in 1:5)
for (c in 1:5)
setCellValue(cells[[r, c]], value = v[(r-1)*5+c])
saveWorkbook(wb, tf <- tempfile(fileext = ".xlsx"))
return(tf)
}
wbsMarkDiff <- function(fn1, fn2) {
fns <- c(fn1, fn2)
wb <- lapply(fns, loadWorkbook)
cs <- lapply(wb, function(x) CellStyle(x) +
Fill(backgroundColor="red",
foregroundColor="red",
pattern="SOLID_FOREGROUND"))
sheets <- lapply(wb, getSheets)
sheetnames <- do.call(intersect, lapply(sheets, names))
for (sheetname in sheetnames) {
sheet <- lapply(sheets, "[[", sheetname)
rows <- lapply(sheet, getRows)
cells <- lapply(rows, getCells)
values <- lapply(cells, function(cell) lapply(cell, getCellValue))
idx <- names(which(!mapply(identical, values[[1]], values[[2]])))
for (s in 1:2)
for (i in idx)
setCellStyle(cells[[s]][[i]], cs[[s]])
for (s in 1:2)
saveWorkbook(wb[[s]], fns[s])
}
}
library(xlsx)
# create to excel workbooks (same dimensions per sheet)
v <- LETTERS[1:25]
tf1 <- wbsCreate(v)
v[c(3,6,9)] <- letters[c(3,6,9)]
tf2 <- wbsCreate(v)
# mark differences
wbsMarkDiff(tf1, tf2)
shell.exec(tf1) # open file1 on windows
shell.exec(tf2) # open file2 on windows
You get help on each command by using ?, for example ?createWorkbook gives you the help files on that function.