QRegEstimator-class: Class for quantile regression-based estimates in the harmonic linear model.
Description
QRegEstimator
is an S4 class that implements the
necessary calculations to determine the frequency
representation based on the weigthed
$L_1$-projection of a time series as described in
Dette et. al (2014+). As a subclass to
FreqRep
it inherits slots and methods defined
there.Details
For each frequency $\omega$ from frequencies
and level $\tau$ from levels
the statistic
$$\hat b^{\tau}_n(\omega) := \arg\max_{a \in R, b \in
C} \sum_{t=0}^{n-1} \rho_{\tau}(Y_t - a - Re(b) \cos(\omega
t) - Im(b) \sin(\omega t)),$$ is determined and stored to
the array values
.
The solution to the minimization problem is determined
using the function rq
from the
quantreg package.
All remarks made in the documentation of the super-class
FreqRep
apply.References
Dette, H., Hallin, M., Kley, T. & Volgushev, S. (2014+). Of
Copulas, Quantiles, Ranks and Spectra: an
$L_1$-approach to spectral analysis.
Bernoulli, forthcoming.