Hoem J M, Madsen D, Nielsen J L, Ohlsen E M, Hansen H O, Rennermalm B
Demography. 1981 May;18(2):231-44.
This paper reports the outcome of an exercise in curve fitting to annual sets of Danish age-specific fertility rates for the years 1962 to 1971 by means of least squares. Functions fitted were a cubic spline, the Hadwiger and Coale-Trussell functions, the gamma and beta densities, two versions of a polynomial, and two of Brass's relational procedures, as well as the Gompertz curve. The spline function fitted all curves far better than any of the others. The Coale-Trussell procedure and gamma density were about equal, followed by the Hadwiger function. All of these functions fit the data wells. One of the polynomials fit reasonably well, but the rest of the functions were less accurate.
本文报告了一项通过最小二乘法对1962年至1971年丹麦按年龄划分的年生育率数据集进行曲线拟合的结果。所拟合的函数有三次样条函数、哈德维格尔函数和科尔-特鲁塞尔函数、伽马密度函数和贝塔密度函数、两种多项式版本、布拉斯的两种关联程序以及冈珀茨曲线。样条函数对所有曲线的拟合效果远优于其他任何函数。科尔-特鲁塞尔程序和伽马密度函数拟合效果大致相当，其次是哈德维格尔函数。所有这些函数对数据的拟合都很好。其中一个多项式拟合效果尚可，但其他函数的拟合精度较低。
