cellWeightsFromResiduals

Given a vector of residuals and a robust scale estimate,
standardize and apply a robust weight function. This is used
inside the IRWLS loop to compute psi-weights from the current
fit residuals.

internal

Provides methods for imputation and visualization of
missing values. It includes graphical tools to explore the amount, structure
and patterns of missing and/or imputed values, supporting exploratory
data analysis and helping to investigate potential missingness mechanisms
(details in Alfons, Templ and Filzmoser, <doi:10.1007/s11634-011-0102-y>).
The quality of imputations can be assessed visually using a wide range of
univariate, bivariate and multivariate plots.
The package further provides several imputation methods,
including efficient implementations of k-nearest neighbour and hot-deck
imputation (Kowarik and Templ 2013, <doi:10.18637/jss.v074.i07>),
iterative robust model-based multiple
imputation (Templ 2011, <doi:10.1016/j.csda.2011.04.012>;
Templ 2023, <doi:10.3390/math11122729>), and machine learning–based
approaches such as robust GAM-based multiple imputation
(Templ 2024, <doi:10.1007/s11222-024-10429-1>) as well as random forest
and gradient boosting (XGBoost) imputation
(Niederhametner et al., <doi:10.1177/18747655251339401>).
General background and practical guidance on imputation are provided in the
Springer book by
Templ (2023) <doi:10.1007/978-3-031-30073-8>.

Matthias Templ

Visualization and Imputation of Missing Values

Alexander Kowarik

Andreas Alfons

Johannes Gussenbauer

Nina Niederhametner

Eileen Vattheuer

Gregor de Cillia

Bernd Prantner

Wolfgang Rannetbauer

cellWeightsFromResiduals function

<dl><dt>residuals</dt>
<dd>numeric n-vector of residuals from the current fit</dd>
<dt>sigma</dt>
<dd>robust scale estimate (e.g. MAD of residuals). If
zero or very small, all weights are set to 1.</dd>
<dt>method</dt>
<dd>weight function: <code>"huber"</code> or <code>"tukey"</code>,
Default: <code>"huber"</code></dd>
<dt>alpha</dt>
<dd>tuning constant. If <code>NULL</code>, the default for
the chosen method is used.</dd></dl>

Arguments

Author

Compute cell weights from regression residuals — cellWeightsFromResiduals

<dl>

<dt>residuals</dt>
<dd>numeric n-vector of residuals from the current fit</dd>


<dt>sigma</dt>
<dd>robust scale estimate (e.g. MAD of residuals). If
zero or very small, all weights are set to 1.</dd>


<dt>method</dt>
<dd>weight function: <code>"huber"</code> or <code>"tukey"</code>,
Default: <code>"huber"</code></dd>


<dt>alpha</dt>
<dd>tuning constant. If <code>NULL</code>, the default for
the chosen method is used.</dd>

</dl>

Compute cell weights from regression residuals

cellWeightsFromResiduals: Compute cell weights from regression residuals

Description

Usage

Value

Arguments

Author