Hi, everyone!
Im using free tier of cloud version of Grafana. My data source is goole spreadsheet with small amount of data that is appended every 24h.
I have a straight forward task of making a gauge panel that would show the difference of how much “stuff” is left in “the thing” today compared to last week. In other words: last week there were 2 amount of “stuff”, today it is 10, so I need the gauge to display number 8.
To do that I use transformations. First I hide unwanted columns using “Organise fields”. Then I sort by date using “Sort” (with reverse). Then I limit the number of items to 7 using “Limit”. Finally I use “Difference” in calculation section of options panel.
I expect to see number 8.
What I get is the “-8”. And vice versa: if the amount of stuff decreased I expect to see “-8” but I get “8”.
I tried to mitigate that by using another Sort transformation to reverse the order of items. But it doesn’t seem to have any effect on the calculation result, though when I look in the table view the first and last values a clearly changing when I toggle Sort on and off.
I don’t see any errors or warning messages. The rest of the dashboard that uses the same data source is perfectly fine.
- I wonder is if there are a way to make calculation “Difference” do what I am trying to achieve?
- Or may be there a way to simply inverse the negative and positive values, something like multiplication by “-1”?
- Or perhaps I just unaware of some proper way of achieving the result that I’m looking for.