Financial functions

NumPy has a number of financial functions:

• The fv() function calculates the so-called future value. The future value gives the value of a financial instrument at a future date, based on certain assumptions.
• The pv() function computes the present value (see https://www.khanacademy.org/economics-finance-domain/core-finance/interest-tutorial/present-value/v/time-value-of-money). The present value is the value of an asset today.
• The npv() function returns the net present value. The net present value is defined as the sum of all the present value cash flows.
• The pmt() function computes the payment against loan principal plus interest.
• The irr() function calculates the internal rate of return. The internal rate of return is the effective interested rate, which does not take into account inflation.
• The mirr() function calculates the modified internal rate of return. The modified internal rate of return is an improved version of the internal rate of return.
• The nper() function returns...