Auto Offset Factor for Axis Labels

[zhiyuanzhai]

Please search existing issues to avoid duplicates.

Current Behavior:
When plotting small/large data, ticks show excessive decimals (0.000025) or cluttered scientific notation on every tick (2.5×10⁻⁸, 3.0×10⁻⁸).

Desired Behavior:
Matplotlib-style offset: ticks show 2.5, 3.0, 3.5 with a single ×10⁻⁸ factor at the axis top.
For example:

   ×10⁻⁸
   5 ┤
     │
   4 ┤
     │
   3 ┤
     │
   2 ┤
     │
   1 ┤
     │_________________________