Scale labels represent textual values for major scale ticks. The label object exposes properties that allow you to specify custom text for scale labels and properties that allow you to change the font for text.
When implementing a callback function for this property, use the scale value to be displayed in a label. This value can be accessed using the fields of the object that is passed as the function's parameter. Alternatively, you can use the this object within the function. This object has the same structure as the object passed as a parameter.
For general information on data formatting, refer to the Data Formatting topic.
Use the scale | label | format | precision option instead.
Specifies a spacing between scale labels and the background bottom edge.