Drawing non-layered tidy trees in linear time

The well-known Reingold–Tilford algorithm produces tidy-layered drawings of trees: drawings where all nodes at the same depth are vertically aligned. However, when nodes have varying heights, layered drawing may use more vertical space than necessary. A non-layered drawing of a tree places children at a fixed distance from the parent, thereby giving a more vertically compact drawing. Moreover, non-layered drawings can also be used to draw trees where the vertical position of each node is given, by adding dummy nodes. In this paper, we present the first linear-time algorithm for producing non-layered drawings. Our algorithm is a modification of the Reingold–Tilford algorithm, but the original complexity proof of the Reingold–Tilford algorithm uses an invariant that does not hold for the non-layered case. We give an alternative proof of the algorithm and its extension to non-layered drawings. To improve drawings of trees of unbounded degree, extensions to the Reingold–Tilford algorithm have been proposed. These extensions also work in the non-layered case, but we show that they then cause a O(n2) run-time. We then propose a modification to these extensions that restores the O(n) run-time

Drawing non-layered tidy trees in linear time

The well-known Reingold–Tilford algorithm produces tidy-layered drawings of trees: drawings where all nodes at the same depth are vertically aligned. However, when nodes have varying heights, layered drawing may use more vertical space than necessary. A non-layered drawing of a tree places children at a fixed distance from the parent, thereby giving a more vertically compact drawing. Moreover, non-layered drawings can also be used to draw trees where the vertical position of each node is given, by adding dummy nodes. In this paper, we present the first linear-time algorithm for producing non-layered drawings. Our algorithm is a modification of the Reingold–Tilford algorithm, but the original complexity proof of the Reingold–Tilford algorithm uses an invariant that does not hold for the non-layered case. We give an alternative proof of the algorithm and its extension to non-layered drawings. To improve drawings of trees of unbounded degree, extensions to the Reingold–Tilford algorithm have been proposed. These extensions also work in the non-layered case, but we show that they then cause a O(n2) run-time. We then propose a modification to these extensions that restores the O(n) run-time

Efficient abstractions for visualization and interaction

Abstractions, such as functions and methods, are an essential tool for any programmer. Abstractions encapsulate the details of a computation: the programmer only needs to know what the abstraction achieves, not how it achieves it. However, using abstractions can come at a cost: the resulting program may be inefficient. This can lead to programmers not using some abstractions, instead writing the entire functionality from the ground up. In this thesis, we present several results that make this situation less likely when programming interactive visualizations. We present results that make abstractions more efficient in the areas of graphics, layout and events

Text and Spatial-Temporal Data Visualization

In this dissertation, we discuss a text visualization system, a tree drawing algorithm, a spatial-temporal data visualization paradigm and a tennis match visualization system. Corpus and corpus tools have become an important part of language teaching and learning. And yet text visualization is rarely used in this area. We present Text X-Ray, a Web tool for corpus-based language teaching and learning and the interactive text visualizations in Text X-Ray allow users to quickly examine a corpus or corpora at different levels of details: articles, paragraphs, sentences, and words. Level-based tree drawing is a common algorithm that produces intuitive and clear presentations of hierarchically structured information. However, new applications often introduces new aesthetic requirements that call for new tree drawing methods. We present an indented level-based tree drawing algorithm for visualizing parse trees of English language. This algorithm displays a tree with an aspect ratio that fits the aspect ratio of the newer computer displays, while presenting the words in a way that is easy to read. We discuss the design of the algorithm and its application in text visualization for linguistic analysis and language learning. A story is a chain of events. Each event has multiple dimensions, including time, location, characters, actions, and context. Storyline visualizations attempt to visually present the many dimensions of a story’s events and their relationships. Integrating the temporal and spatial dimension in a single visualization view is often desirable but highly challenging. One of the main reasons is that spatial data is inherently 2D while temporal data is inherently 1D. We present a storyline visualization technique that integrate both time and location information in a single view. Sports data visualization can be a useful tool for analyzing or presenting sports data. We present a new technique for visualizing tennis match data. It is designed as a supplement to online live streaming or live blogging of tennis matches and can retrieve data directly from a tennis match live blogging web site and display 2D interactive view of match statistics. Therefore, it can be easily integrated with the current live blogging platforms used by many news organizations. The visualization addresses the limitations of the current live coverage of tennis matches by providing a quick overview and also a great amount of details on demand

A Data Science Course for Undergraduates: Thinking with Data

Data science is an emerging interdisciplinary field that combines elements of mathematics, statistics, computer science, and knowledge in a particular application domain for the purpose of extracting meaningful information from the increasingly sophisticated array of data available in many settings. These data tend to be non-traditional, in the sense that they are often live, large, complex, and/or messy. A first course in statistics at the undergraduate level typically introduces students with a variety of techniques to analyze small, neat, and clean data sets. However, whether they pursue more formal training in statistics or not, many of these students will end up working with data that is considerably more complex, and will need facility with statistical computing techniques. More importantly, these students require a framework for thinking structurally about data. We describe an undergraduate course in a liberal arts environment that provides students with the tools necessary to apply data science. The course emphasizes modern, practical, and useful skills that cover the full data analysis spectrum, from asking an interesting question to acquiring, managing, manipulating, processing, querying, analyzing, and visualizing data, as well communicating findings in written, graphical, and oral forms.Comment: 21 pages total including supplementary material

The creative process : gathering for meaning

The creative process of visual artists is not a well-understood methodology for intellectual inquiry. In particular, there are amorphous and individual aspects of it that defy narrow categorization. These aspects, like the gathering and associating labors, which vary from artist to artist, are nonetheless fundamental to our practices. The author investigates how the creative process has been defined and how the creative process is being used outside the traditional artistic context. Artists exist in a space where categories and definitions can be abandoned, where thought is advanced through the act of making, where worldviews can be imagined, where apparent contradictions manipulated, and where materials guide meaning. Arts based research provides an avenue for experimental, experiential, tangible thinking through the creative process. The creative method, derived from the creative process of artists, could one day join the ranks of the scientific method and other recognized methods for intellectual inquiry, leading to the question: can the arts be taught to expand thinking in all fields

Design for green structures in densifying hospital areas : a design proposal for Skåne University Hospital Malmö

Skåne University Hospital Malmö has been going through a process of densification for over 120 years. The original planning of the institution from 1896 was characterised by a castle-like building located in a park environment. Due to the growing city of Malmö the hospital has been forced to adjust and expand. Densification of the hospital area has led to an extensive loss of green space, left are fragments of the former park. The main objective of this research is to make a design proposal for SUS Malmö. The aim is to explore how design can be used as a tool to create resilient green structures in densifying hospital areas. The following questions guide the research: How to design resilient green structures in densifying hospital areas? What are the key challenges? The overarching method is Landscape Biography. This is a method that is based on the notion that landscapes are layered with stories, and shaped by various ongoing processes. It is a method that is interdisciplinary, it includes history, geography and architecture and it is promoted to include methods from other fields as well. The research is non-linear, it includes literature reviews, site analysis, cartographic investigations, historical research, visits to reference landscapes and design. The literature review gives context ABSTRACT to driving forces of densification and theory on alternative strategies in urban planning, including evidence-based design for healthcare environments. Site analysis provides practical knowledge and insights to design challenges within the area. Examination of maps exposes the continuous transformation of SUS Malmö and shed light on green structures that have survived the process. Learnings of former use and values within the landscape are found in historical narratives. Visits to reference landscapes provide inspiration for design and shed light on factors important for the survival of green space. Main findings from the study are explored through design of a specific area within SUS Malmö. The design process is used as a method to investigate the retrieved theoretical and practical knowledge. The result is a design proposal where new insights of the challenges within the landscape become apparent. Many factors affect the resilience of green structures, political, social, historical and aesthetical are some of them. To design for resilience, the various flows within the landscape need to be acknowledged and carefully considered in the process