Description of embed

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embed

PURPOSE

embed --- create an embedding for a graph

SYNOPSIS

function embed(g,xy)

DESCRIPTION

 embed --- create an embedding for a graph
 embed(g,xy) --- set the embedding to xy (an n-by-2 matrix)
 embed(g) --- default circulat embedding

CROSS-REFERENCE INFORMATION

This function calls:

• nv nv(g) --- number of vertices in g
• size size(g) --- returns [nv,ne] for the graph

This function is called by:

• bfstree bfstree(t,g,v) --- create a breadth-first spanning tree of g
• bucky bucky(g) --- overwrite g with the Buckyball graph (and give a nice
• cartesian cartesian(g,h1,h2) --- overwrite g with the product of h1 and h2
• cdraw cdraw(g,coloring) -- draw g with a given vertex coloring
• cube cube(g,k) --- create a k-cube (default k = 3)
• cycle cycle(g,n) --- create a cycle graph on n vertices
• dfstree dfstree(t,g,v) --- create a depth-first spanning tree of g
• disjoint_union disjoint_union(g,h,k) --- overwrite g with the disjoint union of the
• distxy distxy(g) -- give g a distance based embedding
• dodecahedron dodecahedron(g) --- overwrite g with the dodecahedron graph
• draw draw(g) --- draw g in a figure window
• graffle graffle(g, filename, width, rad) --- write graph in OmniGraffle format
• grid grid(g,a,b) --- create an a-by-b grid graph
• icosahedron icosahedron(g) --- overwrite g with the icosahedron graph
• induce induce --- create induced subgraphs
• join join(g,h1,h2) --- overwrite g with the join of h1 and h2
• line_graph line_graph(g,h) --- set g to be the line graph of h
• load load(g,filename) --- read a saved graph on disk
• mdsxy mdsxy(g) -- create an embedding based on multidimensional scaling
• mobius mobius(g,nverts) --- create a Mobius ladder graph
• octahedron octahedron(g) --- overwrite g with the octahedron graph, K(2,2,2)
• path path(g,n) --- make g a path on n vertices
• petersen petersen(g) --- overwrite g with the Petersen graph
• random_bipartite random_bipartite(g,n,m,p) --- create a random bipartite graph
• random_planar random_planar(g,n) --- create a random planar triangulation
• randxy randxy(g) --- give g a random embedding in the plane
• renumber renumber the vertices of a graph
• scale scale(g,s) --- rescale the embedding of g by s
• sgf sgf --- simple graph format: a 2-column matrix representation
• springxy springxy(g) --- find a spring embedding of g

SOURCE CODE

0001 function embed(g,xy)
0002 % embed --- create an embedding for a graph
0003 % embed(g,xy) --- set the embedding to xy (an n-by-2 matrix)
0004 % embed(g) --- default circulat embedding
0005 
0006 global GRAPH_MAGIC;
0007 
0008 n = nv(g);
0009 
0010 if (nargin == 1)
0011     t = [0:n-1]*2*pi/n;
0012     x = n * cos(t)/6;
0013     y = n * sin(t)/6;
0014     xy = [x',y'];
0015 end
0016 
0017 [nr,nc] = size(xy);
0018 if (nr ~= n) | (nc ~= 2)
0019     error('Embedding must be an n-by-2 matrix');
0020 end
0021 
0022 GRAPH_MAGIC.graphs{g.idx}.xy = xy;

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