ESTIMATES OF DERIVATIVES OF (LOG) DENSITIES AND RELATED OBJECTS
密度、对数密度及相关对象的导数估计
We estimate the density and its derivatives using a local polynomial approximation to the logarithm of an unknown density function f . The estimator is guaranteed to be non-negative and achieves the same optimal rate of convergence in the interior as on the boundary of the support of f . The estimator is therefore well-suited to applications in which non-negative density estimates are required, such as in semiparametric maximum likelihood estimation. In addition, we show…