I have a spreadsheet of metrics I track every week. I add a new column to the left every week for that week's data, so that I don't have to scroll forever to the right to see recent information. (Yes, it would be easier to add rows, but that's another story.) All was well until I wanted to add sparklines; since the newer data was on the left, it looked like the sparklines were trending down, when actually the data was just backwards. I needed to find a way to reverse an array in Google Spreadsheets.