For this type of graph we have manually set the distance between each tick label to 25 units. This would put labels as 0,25,50, and so on. The maximum value (the user specifies) will be adjusted so that it is always an even multiple of 25 to allow the last tick mark to be at the end of the axis.
As can be seen from the previous images we are using one feature that hasn't been previously exemplified and that is the possibility to have unique colors on each label on the scale. We use this for the x-scale by having the negative labels in black and the positive labels in white. The reason is purely functional to allow the scale labels to be more easy to read against the colored background.
The color of the labels are specified as the second argument to
Axis::SetColor($aAxisColor,$aLabelColor)
In addition we have also hidden the zero labels since they would just be disturbing in the middle and doesn't really add any information we don't already have.
Finally the labels are formatted to show a percentage sign after each label. This is done by a format string