From The Document Foundation Wiki
- (1) General. Would it be worth adding a link to Wikipedia’s Amortization page?
- (2) Summary. Suggest the following replacement – “Calculates the depreciation for a period using degressive depreciation, applying a depreciation factor that is dependent on the lifetime of the asset”.
- (3) Arguments, Cost. Change “costs” to “cost”.
- (4) Arguments, FirstPeriod. Change “settlement” to “depreciation”.
- (5) Arguments, Salvage. Delete “capital”.
- (6) Arguments, Period. Change to reflect that this should be a non-negative integer. The value of 0 represents the period from the purchase date to the end of the first period. A value of 1 is the next year, and so on. Probably need to add a comment that real values are truncated.
- (7) Arguments, Rate. Mention that it can be specified as a percentage.
- (8) Arguments, Basis. I would include a link to Wikipedia’s “Day count convention” page.
- (9) Arguments, 1st bullet. Suggest the following re-word for better grammar – “If either of DatePurchased or FirstPeriod are not valid dates then the function returns a value (#VALUE!) error.”. However, may be worth mentioning that dates are essentially just numbers (search for "date and time functions" in the Help).
- (10) Arguments, 2nd bullet. Suggest the following re-word for better grammar – “If either Rate or Cost is less than or equal to 0 then the function will return an error value”.
- (11) Arguments, 3rd bullet. Suggest the following re-word for better grammar – “If either Salvage or Period is less than 0 then the function will return an error value.”.
- (12) Arguments, 4th bullet. Insert “the” before “DatePurchased”.
- (13) Arguments, 6th bullet. Change “ny” to “any”. I would remove the text in brackets as it does not really add anything.
- (14) Additional details. The information here is incorrect and should be replaced. I have checked the code and the depreciation coefficients used are based on the Life (i.e. 1/Rate) as follows. If 0 < Life < 3 then the coefficient 1 is used. If 3 <= Life < 5 then the coefficient 1.5 is used. If 5 <= Life <= 6 then the coefficient 2 is used. If Life > 6 then the coefficient 2.5 is used. (This almost matches the information on https://wiki.openoffice.org/wiki/Documentation/How_Tos/Calc:_AMORDEGRC_function but, as previously stated, my information is based on the code and should be assumed correct).
- (15) Additional details. Please explain that if the asset was purchased in the middle of the period, the depreciation is factored accordingly. Hence for period 0 the deprecation is equivalent to ROUND(Depreciation Factor * Cost * Rate * YEARFRAC (Date Purchased; First Period; Basis)). And for period 1 the depreciation is equivalent to ROUND(Depreciation Factor * Rate * (Cost – Depreciation from Previous Period)). And so on…
- (16) Additional details. Also note that the function will not depreciate beyond the point at which the total depreciation is greater than Cost – Salvage.
- (17) Examples, all examples. Delete “settlement”.
- (18) Examples, 3rd example. This example is incorrect. The value of 0 is returned because the asset depreciates so rapidly relative to its Salvage value because of the high Rate. Try a lower Salvage value (e.g. 50) and you will get a non-zero return.
- (19) Examples, general. Maybe include some examples which use the DATE function, enter dates as numbers and use the % format for the Rate argument.