QuantLib：如何计算债券的修正久期？

Question

我遵循了 GB 在本网站上的说明 http://gouthamanbalaraman.com/blog/quantlib-bond-modeling.html

代码如下 - 定义固定利率债券，创建具有期限结构的债券引擎

import matplotlib
matplotlib.use('macosx')
import matplotlib.pyplot as plt
import QuantLib as ql
import pandas as pd

todaysDate = ql.Date(15, 1, 2015)
ql.Settings.instance().evaluationDate = todaysDate
spotDates = [ql.Date(15, 1, 2015), ql.Date(15, 7, 2015), ql.Date(15, 1, 2016)]
spotRates = [0.0, 0.005, 0.007]

dayCount = ql.Thirty360()
calendar = ql.UnitedStates()
interpolation = ql.Linear()
compounding = ql.Compounded
compoundingFrequency = ql.Annual

spotCurve = ql.ZeroCurve(spotDates, spotRates, dayCount, calendar, interpolation,compounding, compoundingFrequency)
spotCurveHandle = ql.YieldTermStructureHandle(spotCurve)


# define the fixed rate bond.

issueDate = ql.Date(15, 1, 2015)
maturityDate = ql.Date(15, 1, 2016)
tenor = ql.Period(ql.Semiannual)
calendar = ql.UnitedStates()
businessConvention = ql.Unadjusted
dateGeneration = ql.DateGeneration.Backward
monthEnd = False
schedule = ql.Schedule (issueDate, maturityDate, tenor, calendar, businessConvention, businessConvention, dateGeneration, monthEnd)


# coupons
dayCount = ql.Thirty360()
couponRate = .06
coupons = [couponRate]

settlementDays = 0
faceValue = 100
fixedRateBond = ql.FixedRateBond(settlementDays, faceValue, schedule, coupons, dayCount)


# create a bond engine with the term structure as input;
# set the bond to use this bond engine
bondEngine = ql.DiscountingBondEngine(spotCurveHandle)
fixedRateBond.setPricingEngine(bondEngine)
print(fixedRateBond.NPV())


#calculating yields
targetPrice = fixedRateBond.cleanPrice()
day_count = dayCount
compounding = ql.Compounded
frequency = 2
ytm = fixedRateBond.bondYield(targetPrice, day_count, compounding, frequency)
print(ytm)

现在如何获得 mod。债券期限？我知道要使用的功能是 ql.BondFunctions.duration(bond,ytm,ql.Duration.Modified) 但这对我不起作用。

Answer 1

持续时间方法的输入利率必须是 InterestRate 对象而不是简单的浮点数，否则您必须通过约定。第一个参数是债券，在您的情况下是 fixedRateBond.

试试这个：

rate = ql.InterestRate(ytm, ql.ActualActual(), ql.Compounded, ql.Annual)
ql.BondFunctions.duration(fixedRateBond,rate,ql.Duration.Modified)

或者这个：

ql.BondFunctions.duration(fixedRateBond,ytm,ql.ActualActual(), ql.Compounded, ql.Annual, ql.Duration.Modified)

QuantLib：如何计算债券的修正久期？

QuantLib : How do I calculate the Modified Duration of a bond?

python

quantlib