GompertzMakeham {fmsb} R Documentation

## Gompertz-Makeham's model mortality for u(x) and its fitting

### Description

Implementing Gompertz-Makeham's model mortality function of the force of mortality u(x) with conversion into qx and fitting the model to actual qx of given lifetable.

### Usage

``` GompertzMakeham(A, B, C, t)
fitGM(initialpar=c(0.01, 0.0003, 0.07), data, mode=1, Method="Nelder-Mead", ...)
```

### Arguments

 `A` The parameter A of the Gompertz-Makeham model u(t)=A*expB*t+C. `B` The parameter B of the Gompertz-Makeham model u(t)=A*expB*t+C. `C` The parameter C of the Gompertz-Makeham model u(t)=A*expB*t+C. `t` Age (vector OK) in years `initialpar` Initial value for the parameters to be estimated. If not given, c(0.01, 0.0003, 0.07) is used. `data` Actual vector of qx in the lifetable to be used to obtain the best-fit parameters of the Gompertz-Makeham model. `mode` Which of lifetable functions should be used to calculate the RMSE, which is to be minimized in optim() function: 1 qx, 2 dx, otherwise lx. Default is 1. `Method` The method to be used in optim() function. Default is "Nelder-Mead". `...` Other options to be passed to optim().

### Value

GompertzMakeham() returns model qx for the same length with t, where u(x) is internally converted into qx. fitGM() returns the numeric vector of fitted parameters of A, B and C, RMSE for those values, and the flag of convergence.

Jlife

### Examples

``` res <- fitGM(,Jlife\$qx2005M)
FLAG <- res[5]
while (FLAG>0) {
res <- fitGM(res[1:3],Jlife\$qx2005M)
FLAG <- res[5]
}
print(res)
```

[Package fmsb Index]