Core Concepts
Optimizing the visibility of symbols in categorical data visualizations by strategically adjusting their x-coordinates within a fixed y-coordinate layout.
Abstract
The paper introduces an algorithmic study on optimizing the visibility of symbols in data visualizations where the symbols must be placed at specified y-coordinates, but their x-coordinates can be adjusted within a rectangular container.
The key insights are:
- When the container width is at most 2, a staircase layout is near-optimal and can be computed efficiently.
- When the container width is at most 2, a 2-approximation algorithm can be used to maximize the minimum visible perimeter of the symbols.
- The proposed algorithms significantly improve the visible perimeter of the symbols compared to a fixed placement, leading to more legible visualizations.
The authors consider unit square symbols, but note that the algorithms readily extend to rectangular symbols as well. Proving similar bounds for more general symbol shapes remains an open challenge.
Stats
The paper does not provide any specific numerical data or statistics. It focuses on the algorithmic analysis of the symbol placement problem.
Quotes
"If the container has width and height at most 2, there is a point that stabs all squares. In this case, we prove that a staircase layout is arbitrarily close to optimality and can be computed in O(n log n) time."
"If the width is at most 2, there is a vertical line that stabs all squares, and in this case, we give a 2-approximation algorithm (assuming fixed container height) that runs in O(n log n) time."