Can anyone kindly explain how system calculate the depreciation amount by method “Factor”?

The introduction of AX manual is too general:

“If the entry in the Factor field is larger than 50, the depreciation is

progressive. This means that the amount of depreciation increases

each depreciation period.

• If the entry in the Factor field is less than 50, the depreciation is

digressive. This means the amount of depreciation decreases each

depreciation period.

• If the entry in the Factor field is 50, depreciation is calculated

exactly like straight-line depreciation.”

Is there any useful formular for this method? I appreciate if anyone can give an example with explaination of this method. Thx in advance. Thank you!