Does any one know how the automatic scaling in graph decides the values to be used(or the alogorithm used to decide the max scale value and min scale value)?
Here is the description of the issue!

I am using manual scaling in my graphs(Bar /Line). But I have problem with numbers that appear on my Y-Axis due to manual setting of values.
1. It is prefrerred that 80-90% of the chart area is utilised in depicting the graph.
2. It is also required to use easily associable numbers for the major unit
eg: Y-Axis is devided as
0 - 10 -20 -30 -40 -50 ... not like 0, 11.1, 22.2, 33.3 etc
0 - 0.5 -1.0 -1.5 -2.0 -2.5 ... not like 0, 0.45, 0.90, 1.35 etc
3. Though the setting Y1MustIncludeZero prints the zero line, the number '0' is not being displayed on the Y-Axis. Only the major unit numbers are being displayed. Zero should be displayed. To my mind the alternative to solve this issue seems to be making sure Zero falls as one of the major units on the Y-Axis.

4. When I have both negative and positive values the problem seems to be compounded, because I see only methods to set the Max scale and minimum scale but not the major unit.
For example I have -50(min), 950(max). The range is 1000. If i devide to 10 units I get 100 as Major unit. But based on the values my graph should start from -100 and extend till 1000(note: but units changed to 11 based on the scenario). And also I expect to see zero in there. But even if I set min and max to these values the behaviour seems to be different from expected.

When Auto scale is true, The graph engine is able to interpret the scales much better. Any help/insight in this regard is very much appreciated!

If you're already setting your Y1 min and max values manually, why don't you set the major grid steps manually too?

This command sets the major unit for the Y1 axis to 20.0 :

setGridStep(getY1MajorGrid(),20.0);

if you've already set the min value to -100, and the max value to 1100, if you set the gridstep to 100, you'll get 0 on the graph, and a decent interval.

Regards

Tewy