I have got a column in an attribute table with values from about -10 to +200. I would like to create a bar chart whose x-axis only has two classes: The first class will have values from -10 up to -1 (only integer values exist), the second class contains all positive values from 0 to 200. How does this work? I don't find a way to edit the amount of classes.
At first, I wanted to create a pie chart, but I noticed quickly that pie charts cannot contain negative values....