The property BuildMethod specifies the method that is used to build a complete fertility curve from a finite set of age-specific fertility rates. The table below gives the BuildMethods currently supported.

BuildMethod Description
CONSTANT_FERT Between age nodes the fertility rate is constant
HFD Between age nodes the transformed fertility rate is a quadratic function of age with curvature continuous across age nodes. This is the method used by the Human Fertility Database.
HYBRID_FERT Between age nodes the transformed fertility rate is a quadratic function of age. Fertility rate does not vary as much as for HFD but curvature is discontinuous across nodes.
COALE_TRUSSELL Fit fertility rates using the 4-parameter Coale-Trussell model.
GAMMA Fit fertility rates using a transformed Gamma functions.
HADWIGER Fit fertility rates using Hadwiger's 4-parameter model.
QUADRATIC_SPLINE Fit fertility rates using Schmertmann's 4-parameter piecewise quadratic model.
CALIBRATED_SPLINE Fit fertility rates with B-splines to maximise projection onto a calibrated set of fertility shapes.
BEERS Fertitilty rates are aggregated into five-years intervals and then split using Beers method.
HFC Fertility rates are split into single-year intervals using CALIBRATED_SPLINE, negative rates are replaced with zeros, and all rates are then rescaled so that the total fertilty rate of the original curve is preserved. This is the method used by the Human Fertility Collection.
BRASS Fertility rates are fitted using the Brass relational fertility model
BETA Fit fertility rate using a parametric model based on the Beta function
HADWIGER_MIX Fit fertility rates using Chandola, Coleman and Hiorns mixture Hadwiger function
PERISTERA_KOSTAKI Peristera and Kostaki's Adjusted Model 2
KERNEL_REGRESSION A non-parametric fit using Kernel regression
SVM A non-parametric fit using Support Vector Machine regression
SMOOTHED_ASFR A non-parametric fit using P-Splines
PTOPALS A relational model that builds the fertility curve using TOPALS and P-Splines
PERISTERA_KOSTAKI6 Peristera and Kostaki's Model 2
WEIBULL_MIX Fit fertility rates using Bermudez, Blanquero, Hernandez and Planelles' Weibull mixture function