1from eng_econ import generate_dcostring 

2 

3 

4@generate_dcostring("F", "P", "Single payment compound amount") 

5def single_payment_compound_amount_factor(i, n): 

6 return (1 + i) ** n 

7 

8 

9@generate_dcostring("P", "F", "Single payment present worth") 

10def single_payment_present_worth_factor(i, n): 

11 return (1 + i) ** (-n) 

12 

13 

14@generate_dcostring("A", "F", "Uniform series sinking fund") 

15def uniform_series_sinking_fund_factor(i, n): 

16 return i / ((1 + i) ** n - 1) 

17 

18 

19@generate_dcostring("A", "P", "Capital recovery") 

20def capital_recovery_factor(i, n): 

21 temporary = (1 + i) ** n 

22 return i * temporary / (temporary - 1) 

23 

24 

25@generate_dcostring("F", "A", "Uniform series compound amount") 

26def uniform_series_compound_amount_factor(i, n): 

27 return ((1 + i) ** n - 1) / i 

28 

29 

30@generate_dcostring("P", "A", "Uniform series present worth") 

31def uniform_series_present_wortht_factor(i, n): 

32 temporary = (1 + i) ** n 

33 return (temporary - 1) / (i * temporary) 

34 

35 

36@generate_dcostring("P", "G", "uniform gradient present worth") 

37def uniform_gradient_present_worth_factor(i, n): 

38 temporary = (1 + i) ** n 

39 return (temporary - 1) / (i ** 2 * temporary) - (n / (i * temporary)) 

40 

41 

42@generate_dcostring("F", "G", "uniform gradient future worth") 

43def uniform_gradient_future_worth_factor(i, n): 

44 return ((1 + i) ** n - 1) / (i ** 2) - (n / i) 

45 

46 

47@generate_dcostring("A", "G", "Uniform gradient uniform series") 

48def uniform_gradient_uniform_series_factor(i, n): 

49 return 1 / i - (n / ((1 + i) ** n - 1))