I'm in a time limited situation on which I have to represent an array of numbers as a chart. The chart is pretty complex, with different scales and representations, because it use a rich library (which is not open source).
At this moment, I need to add a bar chart which represents the positive and negative values of an array. The library that I'm using doesn't generate this type of chart (or I didn't find it yet - but I'm desperate), so I'll have to use something that is already implemented: the function which draws derivatives chart of a series taken as argument.
I know the input array, and in the chart I need to represent the negatives and the positive values not the derivatives (but using the derivatives chart function). I'll have to hack the input array in order to get a chart with positive and negative values marked and not the derivatives.
How do I have to modify the input array?