fmsb (version 0.5.2)

CT: Coale and Trussell's model marital fertility and its fitting

Description

Implementing Coale and Trussell's model of age-specific marital fertility rates and fitting the model to actual ASMFR.

Usage

CT(M=1, m=0) fitCT(initialpar=c(1.0, 1.0), data, Method="Nelder-Mead", ...)

Arguments

M

The parameter M of the CT model, the scale (peak height) parameter of fertility

m

The parameter m of the CT model, the strength of downward discordance from natural fertility with aging

initialpar

Initial value for the parameters to be estimated. If not given, c(1.0, 1.0) is used.

data

Actual vector of ASMFR (which must be given for from age 12 to age 49 for each age) to be used to obtain the best-fit parameters of the CT's model.

Method

The method to be used in optim() function. Default is "Nelder-Mead".

...

Other options to be passed to optim().

Value

CT() returns model ASMFR for ages from 12 to 49. fitCT() returns the numeric vector of fitted parameters M and m, RMSE for those values, and the flag of convergence.

References

Coale AJ, Trussell TJ (1978) Technical Note: Finding the Two Parameters That Specify a Model Schedule of Marital Fertility. Population Index, 44(2): 203-213.

http://www.jstor.org/stable/2735537

See Also

Jfert

Examples

 ASMFR <- c(0, 0, 0, Jfert$ASMFR2000[1:35]) # Jfert's ASMFR should be rearranged to 12:49
 res <- fitCT(,ASMFR)
 FLAG <- res[4]
 while (FLAG>0) {
   res <- fitCT(res[1:2], ASMFR)
   FLAG <- res[4]
 }
 print(res)