89,058 research outputs found
Introducing 3D Venn and Euler Diagrams
No full textIn 2D, Venn and Euler diagrams consist of labelled simple closed curves and have been widely studied. The advent of 3D display and interaction mechanisms means that extending these diagrams to 3D is now feasible. However, 3D versions of these diagrams have not yet been examined. Here, we begin the investigation into 3D Euler diagrams by defining them to comprise of labelled, orientable closed surfaces. As in 2D, these 3D Euler diagrams visually represent the set-theoretic notions of intersection, containment and disjointness. We extend the concept of wellformedness to the 3D case and compare it to wellformedness in the 2D case. In particular, we demonstrate that some data can be visualized with wellformed 3D diagrams that cannot be visualized with wellformed 2D diagrams. We also note that whilst there is only one topologically distinct embedding of wellformed Venn-3 in 2D, there are four such em- beddings in 3D when the surfaces are topologically equivalent to spheres. Furthermore, we hypothesize that all data sets can be visualized with 3D Euler diagrams whereas this is not the case for 2D Euler diagrams, unless non-simple curves and/or duplicated labels are permitted. As this paper is the first to consider 3D Venn and Euler diagrams, we include a set of open problems and conjectures to stimulate further research
Drawing Area-Proportional Venn-3 Diagrams with Convex Polygons
No full textArea-proportional Venn diagrams are a popular way of visualizing the relationships between data sets, where the set intersections have a specified numerical value. In these diagrams, the areas of the regions are in proportion to the given values. Venn-3, the Venn diagram consisting of three intersecting curves, has been used in many applications, including marketing, ecology and medicine. Whilst circles are widely used to draw such diagrams, most area specifications cannot be drawn in this way and, so, should only be used where an approximate solution is acceptable. However, placing different restrictions on the shape of curves may result in usable diagrams that have an exact solution, that is, where the areas of the regions are exactly in proportion to the represented data. In this paper, we explore the use of convex shapes for drawing exact area proportional Venn-3 diagrams. Convex curves reduce the visual complexity of the diagram and, as most desirable shapes (such as circles, ovals and rectangles) are convex, the work described here may lead to further drawing methods with these shapes. We describe methods for constructing convex diagrams with polygons that have four or five sides and derive results concerning which area specifications can be drawn with them. This work improves the state-of-the-art by extending the set of area specifications that can be drawn in a convex manner. We also show how, when a specification cannot be drawn in a convex manner, a non-convex drawing can be generated
Visualizations with Venn and Euler Diagrams
No full textVenn and Euler diagrams intuitively visualize relationships and relative cardinalities of data sets. They are used extensively in areas as biosciences, business and criminology to facilitate data reasoning and analysis. However, current automatic drawing techniques do not always produce desirable diagrams. My research aims to develop novel algorithms to automatically draw readable diagrams that facilitate data analysis. It includes software, theory, and studies demonstrating how such diagrams aid probabilistic judgment
Constructing Area-Proportional Venn and Euler Diagrams with Three Circles
No full textA 3-Venn diagram is used to represent all possible combinations of three characteristics and is most commonly drawn with three overlapping congruent circles. In this paper, we investigate the conditions under which area-proportional circular 3-Venn diagrams exist, and for those untenable cases, we present an optimization strategy for approximating a solution. In the conclusion, we describe how these results can be extended to the case of 3-Euler diagrams
Projections in Venn-Euler Diagrams
No full textVenn diagrams and Euler circles have long been used to express constraints on sets and their relationships with other sets. However, these notations can get very cluttered when we consider many closed curves or contours. In order to reduce this clutter, and to focus attention within the diagram appropriately, the notion of a projected contour, or projection, is introduced. Informally, a projected contour is a contour that describes a set of elements limited to a certain context. Through a series of examples, we develop a formal semantics of projections and discuss the issues involved in introducing these
eulerAPE: Drawing Area-proportional 3-Venn Diagrams Using Ellipses
No full textVenn diagrams with three curves are used extensively in various medical and scientific disciplines to visualize relationships between data sets and facilitate data analysis. The area of the regions formed by the overlapping curves is often directly proportional to the cardinality of the depicted set relation or any other related quantitative data. Drawing these diagrams manually is difficult and current automatic drawing methods do not always produce appropriate diagrams. Most methods depict the data sets as circles, as they perceptually pop out as complete distinct objects due to their smoothness and regularity. However, circles cannot draw accurate diagrams for most 3-set data and so the generated diagrams often have misleading region areas. Other methods use polygons to draw accurate diagrams. However, polygons are non-smooth and non-symmetric, so the curves are not easily distinguishable and the diagrams are difficult to comprehend. Ellipses are more flexible than circles and are similarly smooth, but none of the current automatic drawing methods use ellipses.
We present eulerAPE as the first method and software that uses ellipses for automatically drawing accurate area-proportional Venn diagrams for 3-set data. We describe the drawing method adopted by eulerAPE and we discuss our evaluation of the effectiveness of eulerAPE and ellipses for drawing random 3-set data. We compare eulerAPE and various other methods that are currently available and we discuss differences between their generated diagrams in terms of accuracy and ease of understanding for real world data
Visualizing Set Relations and Cardinalities Using Venn and Euler Diagrams
No full textIn medicine, genetics, criminology and various other areas, Venn and Euler diagrams are used to visualize data set relations and their cardinalities. The data sets are represented by closed curves and the data set relationships are depicted by the overlaps between these curves. Both the sets and their intersections are easily visible as the closed curves are preattentively processed and form common regions that have a strong perceptual grouping effect. Besides set relations such as intersection, containment and disjointness, the cardinality of the sets and their intersections can also be depicted in the same diagram (referred to as area-proportional) through the size of the curves and their overlaps. Size is a preattentive feature and so similarities, differences and trends are easily identified. Thus, such diagrams facilitate data analysis and reasoning about the sets. However, drawing these diagrams manually is difficult, often impossible, and current automatic drawing methods do not always produce appropriate diagrams.
This dissertation presents novel automatic drawing methods for different types of Euler diagrams and a user study of how such diagrams can help probabilistic judgement. The main drawing algorithms are: eulerForce, which uses a force-directed approach to lay out Euler diagrams; eulerAPE, which draws area-proportional Venn diagrams with ellipses. The user study evaluated the effectiveness of area- proportional Euler diagrams, glyph representations, Euler diagrams with glyphs and text+visualization formats for Bayesian reasoning, and a method eulerGlyphs was devised to automatically and accurately draw the assessed visualizations for any Bayesian problem. Additionally, analytic algorithms that instantaneously compute the overlapping areas of three general intersecting ellipses are provided, together with an evaluation of the effectiveness of ellipses in drawing accurate area-proportional Venn diagrams for 3-set data and the characteristics of the data that can be depicted accurately with ellipses
Some Results for Drawing Area Proportional Venn3 With Convex Curves
No full textMany data sets are visualized effectively with area proportional Venn diagrams, where the area of the regions is in proportion to a defined specification. In particular, Venn diagrams with three intersecting curves are considered useful for visualizing data in many applications, including bioscience, ecology and medicine. To ease the understanding of such diagrams, using restricted nice shapes for the curves is considered beneficial. Many research questions on the use of such diagrams are still open. For instance, a general solution to the question of when given area specifications can be represented by Venn3 using convex curves is still unknown. In this paper we study symmetric Venn3 drawn with convex curves and show that there is a symmetric area specification that cannot be represented with such a diagram. In addition, by using symmetric diagrams drawn with polygons, we show that, if area specifications are restricted so that the double intersection areas are no greater than the triple intersection area then the specification can be drawn with convex curves. We also propose a construction that allows the representation of some area specifications when the double intersection areas are greater than the triple intersection area. Finally, we present some open questions on the topic
Fragments of Spider Diagrams of Order and their Relative Expressiveness
No full textInvestigating the expressiveness of a diagrammatic logic provides insight into how its syntactic elements interact at the semantic level. Moreover, it allows for comparisons with other notations. Various expressiveness results for diagrammatic logics are known, such as the theorem that Shin's Venn-II system is equivalent to monadic first order logic. The techniques employed by Shin for Venn-II were adapted to allow the expressiveness of Euler diagrams to be investigated. We consider the expressiveness of spider diagrams of order (SDoO), which extend spider diagrams by including syntax that provides ordering information between elements. Fragments of SDoO are created by systematically removing each aspect of the syntax. We establish the relative expressiveness of the various fragments. In particular, one result establishes that spiders are syntactic sugar in any fragment that contains order, negation and shading. We also show that shading is syntactic sugar in any fragment containing negation and spiders. The existence of syntactic redundancy within the spider diagram of order logic is unsurprising however, we find it interesting that spiders or shading are redundant in fragments of the logic. Further expressiveness results are presented throughout the paper. The techniques we employ may well extend to related notations, such as the Euler/Venn logic of Swoboda et al. and Kent's constraint diagrams
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