PDEstrip: 1D Density Strip based on Pareto Density Estimation (PDE)
Description
This function renders a single variable's probability density as a horizontal "heat strip",
where color encodes local density values. Low-density regions are shown in blue/green,
medium-density regions in yellow, and high-density regions in orange/red.
It provides a compact alternative to violin or box plots for visualizing the distribution
of a single variable.
A ggplot object showing a 1D density strip for the given feature.
Arguments
Feature
Numeric vector. Finite values are used for Pareto Density Estimation (PDE).
Non-finite values are ignored.
palette
Character vector of colors defining the low-to-high density gradient,
passed to ggplot2::scale_fill_gradientn().
Default is a five-color palette ranging from blue (low density) to red (high density).
Author
Michael Thrun
Details
Density is estimated via Pareto Density Estimation (PDE), a robust and adaptive
approach to probability density estimation [Ultsch, 2005]. The returned
density values are min-max normalized to [0,1] and mapped to the user-specified
color gradient. The strip is drawn with geom_tile() at a fixed y=1, so that
each feature is visualized as a single horizontal band. The feature name is
automatically captured from the input expression and used as the x-axis label.
References
Ultsch, A.: Pareto Density Estimation: A Density Estimation for Knowledge Discovery, Baier D., Wernecke K.D. (Eds), In Innovations in Classification, Data Science, and Information Systems - Proceedings 27th Annual Conference of the German Classification Society (GfKL) 2003, Berlin, Heidelberg, Springer, pp, 91-100, 2005.