Recent empirical research has indicated that human graph reading performance improves when crossing angles increase. However, crossing angle has not been used as an aesthetic criterion for graph drawing algorithms so far. In this paper, we introduce a force-directed method that aims to construct graph drawings with large crossing angles. Experiments indicate that our method significantly increa...

Taking both perceptual organization and aesthetic criteria into account is the key to high-quality diagram layout, but makes for a more di cult problem than pure aesthetic layout. Computing the layout of a network diagram that exhibits a speci ed perceptual organization can be phrased as a constraint-satisfaction problem. Some constraints are derived from the perceptual-organization speci catio...

Visualization of object-oriented programs by class diagrams is a widely used technique. So far no commonly agreed aesthetic criteria have been recorded in order to standardize and measure the quality of class diagrams. In this paper we focus on UML class diagrams, the standard notation for class diagrams in software engineering. We propose some aesthetic criteria which reflect the highly sophis...

Graph layouts are in general data dependent and help to reveal structural and attribute relationships in the data set. However, there are situations when one may wish to alter the layout e.g. to emphasize parts of the data set or for aesthetic reasons. This paper strives to meet that need for the case of force-directed graph layout algorithms. Our approach is to add boundary constraints to spec...

A common problem in visualising some networks is the presence of localised high density areas in an otherwise sparse graph. Applying common graph drawing algorithms on such networks can result in drawings that are not highly readable in the dense areas. Additionally, networks whose layouts are defined geographically often have dense areas that are located within small geographical regions relat...

We propose a layout algorithm for micro/macro graphs, i.e. relational structures with two levels of detail. While the micro-level graph is given, the macro-level graph is induced by a given partition of the micro-level vertices. A typical example is a social network of employees organized into different departments. We do not impose restrictions on the macro-level layout other than sufficient t...

Constrained graph layout is a recent generalisation of forcedirected graph layout which allows constraints on node placement. We give a constrained graph layout algorithm that takes an initial feasible layout and improves it while preserving the topology of the initial layout. The algorithm supports poly-line connectors and clusters. During layout the connectors and cluster boundaries act like ...

In this paper we consider the problem of drawing and displaying a series of related graphs, i.e., graphs that share all, or parts of the same vertex set. We designed and implemented three different algorithms for simultaneous graphs drawing and three different visualization schemes. The algorithms are based on a modification of the force-directed algorithm that allows us to take into account ve...

A recent line of work in graph drawing studies Lombardi drawings, i.e., drawings with circular-arc edges and perfect angular resolution at vertices. Little has been known about the effects of curved edges versus straight edges in typical graph reading tasks. In this paper we present the first user evaluation that empirically measures the readability of three different layout algorithms (traditi...

Enabling the user of a graph drawing system to preserve the mental map between two different layouts of a graph is a major problem. In this paper we present methods that smoothly transform one drawing of a graph into another without any restrictions to the class of graphs or type of layout algorithm. Communicated by M. Kaufmann: submitted February 2001; revised February 2002. Research supported...