Python中的 numpy.pv()

numpy.fv(rate, nper, pmt, fv, when = 'end') ：此财务函数可帮助用户计算未来值。

参数 ：

rate : [array_like] Rate of interest as decimal (not per cent) per period
nper : [array_like] total compounding periods
pmt : [array_like] fixed payment
fv : [array_like, optional] future value. Default = 0.0
when : at the beginning (when = {‘begin’, 1}) or the end (when = {‘end’, 0}) of each period. Default is {‘end’, 0}

返回 ：

present value as per given parameters.

正在求解的方程：

fv + pv*(1 + rate)**nper +
pmt*(1 + rate*when)/rate*((1 + rate)**nper - 1) = 0

或当速率 == 0

fv + pv + pmt * nper = 0

代码 1：工作

## Python program explaining pv() function
  
import numpy as np
'''
Question : 
  
What is the present value (e.g., the initial investment)
of an investment that needs to total $15692.93 after 10
years of saving $100 every month? 
Assume the interest rate is 5% (annually) compounded monthly.
'''
  
#                 rate        np       pmt   fv
Solution = np.pv(0.05/12, 10*12, -100, 15692.93)
  
print("present value (fv) : ", Solution)

输出 ：

present value (fv) :  -100.000671316

参考 ：
https://docs.scipy.org/doc/numpy-1.13.0/reference/generated/numpy.pv.html