CODEWITHSUNDEEP
rdataframe
Gabriel G.
Gabriel G.

Reputation: 822

How to add a line of metadata above a dataframe

My question is probably very simple, but I can't find an answer

I have the dataframe (where the first row are in fact colnames)

      a      b       c     d      e
   1
   2
   3
   4
   5

And I need to include some metadata:

      >this is metadata
      a      b       c     d      e
   1
   2
   3
   4
   5

How can I do that?

Upvotes: 3

Views: 844

Answers (2)

M.K. Reeves
M.K. Reeves

Reputation: 11

Easiest way is to use openxlsx.

https://cran.r-project.org/web/packages/openxlsx/vignettes/Introduction.html

as in:

header <- "this is metadata"
df <- my dataframe

wb <- createWorkbook()
#create an empty workbook
    addWorksheet(wb, sheetName = "df_name", gridLines = F) 
#add one or more worksheets specifying the name you want for the worksheet
    writeData(wb, 1, x = header, startCol = 1, startRow = 1)
#write your header to the workbook
    writeDataTable(wb, sheet = 1, df, startCol = 1, startRow = 2)#)
#write your data to the workbook
    saveWorkbook(wb, "df_name.xlsx", overwrite = TRUE)
#export your workbook to excel file

#not run for this example

Upvotes: 1

slava-kohut
slava-kohut

Reputation: 4233

There are two things you could do if you want to retain some metadata:

1) If you want to manipulate data frames with metadata in your R session, you can create a new S3 class that inherits from data.frame and add a metadata attribute to it. You can find some relevant information here

2) If you want to save a data frame with metadata to disk, you can add a comment line at the top of your csv file (or any other format that you prefer). Something like this will work:

con <- file(paste0(base_path, file_name),'wt')

cat(paste0(comment_string,'\n'), file = con)
write.table(your_data_frame,
              con,
              append = TRUE,
              sep = ',',
              dec = '.',
              row.names = FALSE,
              col.names = FALSE)

close(con)

where comment_string is your metadata and your_data_frame is your data frame.

Upvotes: 4

Related Questions