This is the IRR of the loan's cashflow, after adding all the extra costs
Usage
cft(amt, maturity, rate, up_fee = 0, per_fee = 0)
Arguments
amt
The amount of the loan
maturity
The maturity of the loan
rate
The loan rate, in effective rate
up_fee
The fee that the loan taker pays upfront
per_fee
The fee that the loan payer pays every period
Details
It is assumed that the loan has monthly payments
The CFT is returned as an effective rate of periodicity equal to that of the maturity and the rate
The interest is calculated over amt + fee