  We propose a user-friendly graphical tool, the half-disk density strip
(HDDS), for visualizing and comparing probability density functions. The HDDS
exploits color shading for representing a distribution in an intuitive way. In
univariate settings, the half-disk density strip allows to immediately discern
the key characteristics of a density, such as symmetry, dispersion, and
multi-modality. In the multivariate settings, we define HDDS tables to
generalize the concept of contingency tables. It is an array of half-disk
density strips, which compactly displays the univariate marginal and
conditional densities of a variable of interest, together with the joint and
marginal densities of the conditioning variables. Moreover, HDDSs are by
construction well suited to easily compare pairs of densities. To highlight the
concrete benefits of the proposed methods, we show how to use HDDSs for
analyzing income distribution and life-satisfaction, conditionally on
continuous and categorical controls, from survey data. The code for
implementing HDDS methods is made available through a dedicated R package.
