rLifes: Function to generate random future lifetimes

In lifecontingencies: Financial and Actuarial Mathematics for Life Contingencies

Function to generate random future lifetimes

Description

Function to generate random future lifetimes

Usage

rLife(n, object, x = 0, k = 1, type = "Tx")

rLifexyz(n, tablesList, x, k = 1, type = "Tx")

Arguments

n	Number of variates to generate
object	An object of class lifetable
x	The attained age of subject x, default value is 0
k	Number of periods within the year when it is possible death to happen, default value is 1
type	Either "Tx" for continuous future lifetime, "Kx" for curtate future lifetime (can be abbreviated).
tablesList	An list of lifetables

Details

Under the uniform distribution of deaths assumption the complete future lifetime is the curtate one plus an independent uniform fraction of year, T_x=K_x+U with U\sim Unif(0,1), hence E[T_x]=E[K_x]+0.5. For type="Tx" the function returns K_x+0.5/k, i.e. a deterministic mid-period fraction, so only the expected value (not the full distribution) of T_x is reproduced.

Value

A numeric vector of n elements.

Note

The function is provided as is, without any warranty regarding the accuracy of calculations. The author disclaims any liability for eventual losses arising from direct or indirect use of this software.

References

Actuarial Mathematics (Second Edition), 1997, by Bowers, N.L., Gerber, H.U., Hickman, J.C., Jones, D.A. and Nesbitt, C.J.

See Also

lifetable, exn

Examples

## Not run: 
##get 20000 random future lifetimes for the Soa life table at birth
data(soa08Act)
lifes=rLife(n=20000,object=soa08Act, x=0, type="Tx")
# check if the expected life at birth derived from the life table is statistically equal
# to the expected value of the sample
t.test(x=lifes, mu=exn(soa08Act, x=0, type="continuous"))

## End(Not run)
## Not run: 
#assessment of curtate expectation of future lifetime of the joint-life status
#generate a sample of lifes
data(soaLt)
soa08Act=with(soaLt, new("actuarialtable",interest=0.06,x=x,lx=Ix,name="SOA2008"))
tables=list(males=soa08Act, females=soa08Act)
xVec=c(60,65)
test=rLifexyz(n=50000, tablesList = tables,x=xVec,type="Kx")
#check first survival status
t.test(x=apply(test,1,"min"),mu=exyzt(tablesList=tables, x=xVec,status="joint"))
#check last survival status
t.test(x=apply(test,1,"max"),mu=exyzt(tablesList=tables, x=xVec,status="last"))

## End(Not run)

lifecontingencies documentation built on Oct. 10, 2026, 9:06 a.m.