Anderson, James Andrew; Head, Thomas J. (2006), Automata Theory with Modern Applications, Cambridge University Press, pp.38–41, ISBN 978-0-521-84887-9 . Bioinformatics including phylogenetic trees, protein–protein interaction networks, and metabolic pathways. [27] Several commonly used quality measures concern lengths of edges: it is generally desirable to minimize the total length of the edges as well as the maximum length of any edge. Additionally, it may be preferable for the lengths of edges to be uniform rather than highly varied. Pach, János; Sharir, Micha (2009), "5.5 Angular resolution and slopes", Combinatorial Geometry and Its Algorithmic Applications: The Alcalá Lectures, Mathematical Surveys and Monographs, vol.152, American Mathematical Society, pp.126–127 . In the case of directed graphs, arrowheads form a commonly used graphical convention to show their orientation; [2] however, user studies have shown that other conventions such as tapering provide this information more effectively. [6] Upward planar drawing uses the convention that every edge is oriented from a lower vertex to a higher vertex, making arrowheads unnecessary. [7]

The crossing number of a drawing is the number of pairs of edges that cross each other. If the graph is planar, then it is often convenient to draw it without any edge intersections; that is, in this case, a graph drawing represents a graph embedding. However, nonplanar graphs frequently arise in applications, so graph drawing algorithms must generally allow for edge crossings. [10] Symmetry display is the problem of finding symmetry groups within a given graph, and finding a drawing that displays as much of the symmetry as possible. Some layout methods automatically lead to symmetric drawings; alternatively, some drawing methods start by finding symmetries in the input graph and using them to construct a drawing. [11]The slope number of a graph is the minimum number of distinct edge slopes needed in a drawing with straight line segment edges (allowing crossings). Cubic graphs have slope number at most four, but graphs of degree five may have unbounded slope number; it remains open whether the slope number of degree-4 graphs is bounded. [12] BioFabric open-source software for visualizing large networks by drawing nodes as horizontal lines. Visualization of node-link graphs Graphic representation of a minute fraction of the WWW, demonstrating hyperlinks. Graphviz and Dynagraph – Static and Dynamic Graph Drawing Tools", by John Ellson, Emden R. Gansner, Eleftherios Koutsofios, Stephen C. North, and Gordon Woodhull, in Jünger & Mutzel (2004).

Nachmanson, Lev; Robertson, George; Lee, Bongshin (2008), "Drawing Graphs with GLEE" (PDF), in Hong, Seok-Hee; Nishizeki, Takao; Quan, Wu (eds.), Graph Drawing, 15th International Symposium, GD 2007, Sydney, Australia, September 24–26, 2007, Revised Papers, Lecture Notes in Computer Science, vol.4875, Springer-Verlag, pp.389–394, doi: 10.1007/978-3-540-77537-9_38, ISBN 978-3-540-77536-2 [ permanent dead link]. Spectral layout methods use as coordinates the eigenvectors of a matrix such as the Laplacian derived from the adjacency matrix of the graph. [15] Koren, Yehuda (2005), "Drawing graphs by eigenvectors: theory and practice", Computers & Mathematics with Applications, 49 (11–12): 1867–1888, doi: 10.1016/j.camwa.2004.08.015, MR 2154691 .Herman, Ivan; Melançon, Guy; Marshall, M. Scott (2000), "Graph Visualization and Navigation in Information Visualization: A Survey", IEEE Transactions on Visualization and Computer Graphics, 6 (1): 24–43, doi: 10.1109/2945.841119 .

Many different quality measures have been defined for graph drawings, in an attempt to find objective means of evaluating their aesthetics and usability. [9] In addition to guiding the choice between different layout methods for the same graph, some layout methods attempt to directly optimize these measures. Bachmaier, Christian; Brandes, Ulrik; Schreiber, Falk (2014), "Biological Networks", in Tamassia, Roberto (ed.), Handbook of Graph Drawing and Visualization, CRC Press, pp.621–651 . Microsoft Automatic Graph Layout, open-source .NET library (formerly called GLEE) for laying out graphs [31] Di Battista, Giuseppe; Eades, Peter; Tamassia, Roberto; Tollis, Ioannis G. (1994), "Algorithms for Drawing Graphs: an Annotated Bibliography", Computational Geometry: Theory and Applications, 4 (5): 235–282, doi: 10.1016/0925-7721(94)00014-x, archived from the original on 2016-03-27 , retrieved 2007-03-19 . Saaty, Thomas L. (1964), "The minimum number of intersections in complete graphs", Proc. Natl. Acad. Sci. U.S.A., 52 (3): 688–690, Bibcode: 1964PNAS...52..688S, doi: 10.1073/pnas.52.3.688, PMC 300329, PMID 16591215 .

Draw on graph paper online

Freese, Ralph (2004), "Automated lattice drawing", in Eklund, Peter (ed.), Concept Lattices: Second International Conference on Formal Concept Analysis, ICFCA 2004, Sydney, Australia, February 23-26, 2004, Proceedings (PDF), Lecture Notes in Computer Science, vol.2961, Springer-Verlag, pp.589–590, CiteSeerX 10.1.1.69.6245, doi: 10.1007/978-3-540-24651-0_12, ISBN 978-3-540-21043-6, archived (PDF) from the original on 2016-03-14 , retrieved 2011-09-17 . Tamassia, Roberto, ed. (2014), Handbook of Graph Drawing and Visualization, CRC Press, archived from the original on 2013-08-15 , retrieved 2013-08-28 . Data-flow diagrams, drawings in which the nodes represent the components of an information system and the edges represent the movement of information from one component to another.