print to pdf file using grid.table in r - too many rows to fit on one page

Question

I'm trying to output a dataframe of about 40 rows and 5 columns to a .pdf file using grid.table in gridExtra package of R.

However, 40 rows is too long for a page so the .pdf file only shows part of the dataframe. I want to know if I can print two columns on one page so all of the rows show up on one page. Alternatively, I need to know how to print the dataframe over multiple pages. Thanks, John

Answer 1

Try this for drawing table on a pdf file that span multiple pages using gridExtra package:

1. Adjust pdf device aspect ratio

   pdf(file = myfile.pdf, height = 12, width = 26)
   

2. Split the large data frame into chunks and call grid.newpage before drawing a table.

   require(gridExtra)
   pdf(file = myfile.pdf, height = 12, width = 26)
   grid.newpage()
   grid.table(sga_hits[1:38, ], show.rownames = FALSE)
   grid.newpage()
   grid.table(sga_hits[39:75, ], show.rownames = FALSE)
   dev.off()
   

Automate the above as follows:

    require(gridExtra)
    pdf(file = myfile.pdf, height = 12, width = 26)
    total_rows_per_page = 38 
    start_row = 1 

    if(total_rows_per_page > nrow(sga_hits)){
         end_row = nrow(sga_hits)
    }else {
         end_row = total_rows_per_page 
    }    

    for(i in 1:ceiling(nrow(sga_hits)/total_rows_per_page)){

       grid.newpage()   

       grid.table(sga_hits[start_row:end_row, ], show.rownames = FALSE)

       start_row = end_row + 1

       if((total_rows_per_page + end_row) < nrow(sga_hits)){

            end_row = total_rows_per_page + end_row

       }else {

            end_row = nrow(sga_hits)
       }    
    }

    dev.off()