Calculates the force of interest (δ) given the effective annual interest rate.
Formula: δ = ln(1 + i)
The effective annual interest rate as a decimal (e.g., 0.06 for 6%).
The force of interest δ.
Will throw an error if i is less than or equal to -1 (which would make ln(1 + i) invalid).
Calculates the force of interest (δ) given the effective annual interest rate.
Formula: δ = ln(1 + i)