I am trying to set up a chart, which would have several categories of very different magnitudes. For example, imagine a chart of two trends: total number of some kind of events in millions and a number of events with errors in, say, hundreds or thousands. Errors will be invisible without logarithmic Y scale. So I want Y-axis to go 1, 10, 100, 1000, 10000 etc. instead of 1, 2, 3, 4... One possible way is to do it on a level of DB query: "select category, log10(amount) from ...", but it changes the labels on the Y-axis to logarithms. I want labels to stay the same: original number of events.