@spec continuous_to_periodic(number(), number()) :: {:ok, float()} | {:error, error()}

The per-period rate equivalent to a continuously-compounded annual rate, for periods periods a year.

e^(rate / periods) − 1

iex> {:ok, r} = Finance.Rates.continuous_to_periodic(0.10, 1)
iex> Float.round(r, 6)
0.105171

@spec continuous_to_periodic!(number(), number()) :: float()

Same as continuous_to_periodic/2, but returns the rate directly and raises ArgumentError on error.

@spec effective_annual_rate(number(), number()) :: {:ok, float()} | {:error, error()}

The effective annual rate earned by a nominal rate compounded m times a year.

(1 + nominal / m)^m − 1

iex> {:ok, ear} = Finance.Rates.effective_annual_rate(0.10, 12)
iex> Float.round(ear, 6)
0.104713

@spec effective_annual_rate!(number(), number()) :: float()

Same as effective_annual_rate/2, but returns the rate directly and raises ArgumentError on error.

@spec nominal_rate(number(), number()) :: {:ok, float()} | {:error, error()}

The nominal rate that, compounded m times a year, produces the effective annual rate. The inverse of effective_annual_rate/2.

m · ((1 + effective)^(1/m) − 1)

iex> {:ok, ear} = Finance.Rates.effective_annual_rate(0.10, 12)
iex> {:ok, nominal} = Finance.Rates.nominal_rate(ear, 12)
iex> Float.round(nominal, 10)
0.1

@spec nominal_rate!(number(), number()) :: float()

Same as nominal_rate/2, but returns the rate directly and raises ArgumentError on error.