Rose Charts

Abstract

This paper examines the accuracy of value estimation from the fill level in circle sectors of rose charts, a circular chart type where all sectors share the same angle and encode values through either radius or area. We conducted a user study comparing different sector configurations and chart sizes, as well as estimation errors for rose and bar charts.

Our findings indicate that both area and radius influence estimation accuracy. For values below 65%, area dominates as a visual cue, while for larger values a transition to length perception can be observed. Based on these insights, we propose a transfer function to correct for average estimation errors and provide practical guidelines for the effective use of rose charts.

Publication

D. Kiesel, P. Riehmann, and B. Froehlich. Rose Charts: Area or Length Encoding for Fill Level of Circle Sectors? Short Paper to be presented at EuroVis 2025. Preprint, Video