ddpoly


a numeric vector at which to evaluate the polynomial. <code>x</code> can also be a matrix. Missing values are not allowed in <code>x</code>.



the degree of the polynomial. Must be less than the number of unique points if <code>raw = TRUE</code>.


degree


for prediction, coefficients from a previous fit.


coefs


if true, use raw and not orthogonal polynomials.



	Returns or evaluates the second derivatives of orthogonal polynomials of degree 1 to <code>degree</code> over the specified set of points <code>x</code>: the polynomials are all orthogonal to the constant polynomial of degree 0. Alternatively, evaluates the second derivatives of raw polynomials.


Implements the nonparametric quantile regression method developed by Belloni, Chernozhukov, and Fernandez-Val (2011) to partially linear quantile models. Provides point estimates of the conditional quantile function and its derivatives based on series approximations to the nonparametric part of the model. Provides pointwise and uniform confidence intervals using analytic and resampling methods.

ddpoly: Compute Second Derivative of Orthogonal Polynomials

Description

Usage

Arguments

Value

References

See Also