Net Present Value (periodic cash flows)
Calculates of Net Present Value (NPV) of a series of periodic cash flows with an initial investment (C) followed by cash flows F1 F2 F3 ... .
`NPV = -C + F_1/(1+r)^i+F_2/(1+r)^2+F_3/(1+r)^3...`
If cash flows are non-periodic (custom dates), this calculator would be more adapted NPV with non-periodic cash flows.