Python中的 numpy.ppmt()

numpy.ppmt(rate, nper, pv, fv, when = 'end') ：此财务函数可帮助用户仅根据本金价值计算支付价值。

Parameters :
rate : [scalar or (M, )array] Rate of interest as decimal (not per cent) per period
nper : [scalar or (M, )array] total compounding periods
fv : [scalar or (M, )array] Future value
pv : [scalar or (M, )array] present value
when : at the beginning (when = {‘begin’, 1}) or the end (when = {‘end’, 0}) of each period.Default is {‘end’, 0}

Return : Payment value as per the principal value only.

正在求解的方程：

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

or when rate == 0
fv + pv + pmt * nper == 0

代码：

# Python program explaining 
# ppmt() function 
  
import numpy as np 
  
''' 
Question : 
  
monthly payment needed to pay off a $10, 000 loan
in 12 years at an annual interest rate of 10 %
'''
  
# rate     np         pv 
Solution = np.ppmt(0.10 / 12, 12 * 12,  10, 000) 
  
# Here fv = 0 ; Also Default value of fv = 0 
print("Solution : ", Solution) 

输出：

Solution :  -0.1195078262827336