There is no obligation to call AxisChange() for manually scaled axes. AxisChange() is only intended to handle auto scaling operations. Call this function anytime you change, add, or remove curve data to insure that the scale range of the axes are appropriate for the data range. This method calculates a scale minimum, maximum, and step size for each axis based on the current curve data. Only the axis attributes (min, max, step) that are set to auto-range (MinAuto, MaxAuto, MajorStepAuto) will be modified. You must call Invalidate()() after calling AxisChange to make sure the display gets updated.
This overload of AxisChange just uses the default Graphics instance for the screen. If you have a Graphics instance available from your Windows Form, you should use the AxisChange(Graphics) overload instead.