def present_value(amount, rate, t):
cf = CashFlow(amount=amount, t=t)
return cf.present_value(ir=rate)
def future_value(amount, rate, t):
cf = CashFlow(amount=amount, t=0)
return cf.shift(t=t, ir=rate)
def present_value(amount, rate, t):
cf = CashFlow(amount=amount, t=t)
return cf.present_value(ir=rate)
def future_value(amount, rate, t):
cf = CashFlow(amount=amount, t=0)
return cf.shift(t=t, ir=rate)
