Description of complete

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complete

PURPOSE

complete: build complete and complete multipartite graphs

SYNOPSIS

function complete(g,a,b)

DESCRIPTION

 complete: build complete and complete multipartite graphs
 complete(g) --- convert g to a complete graph on same vertex set
 complete(g,a) --- convert g to a complete graph on a vertices
 complete(g,a,b) --- convert g to K(a,b)
 complete(g,list) --- convert g to a multipartite graph

CROSS-REFERENCE INFORMATION

This function calls:

• fast_set_matrix fast_set_matrix(g,A) --- overwrite the adjacency matrix of g with A
• nv nv(g) --- number of vertices in g

This function is called by:

• cube cube(g,k) --- create a k-cube (default k = 3)
• mycielski mycielski(g,n) --- create n'th order Mycielski graph (n > 0)

SOURCE CODE

0001 function complete(g,a,b)
0002 % complete: build complete and complete multipartite graphs
0003 % complete(g) --- convert g to a complete graph on same vertex set
0004 % complete(g,a) --- convert g to a complete graph on a vertices
0005 % complete(g,a,b) --- convert g to K(a,b)
0006 % complete(g,list) --- convert g to a multipartite graph
0007 
0008 global GRAPH_MAGIC
0009 
0010 % convert existing graph to complete
0011 
0012 if nargin==1
0013     n = nv(g);
0014     fast_set_matrix(g,(ones(n) - eye(n)));
0015     return
0016 end
0017 
0018 % overwrite with K_a
0019 
0020 if (nargin==2) & (length(a)==1)
0021     fast_set_matrix(g,ones(a)-eye(a));
0022     return
0023 end
0024 
0025 % overwrite with K(a,b)
0026 
0027 if (nargin==3)
0028     A = zeros(a,a);
0029     B = zeros(b,b);
0030     Z = ones(a,b);
0031     fast_set_matrix(g,[A,Z;Z',B]);
0032     return
0033 end
0034 
0035 % last case: complete multipartite graph (a is a list)
0036 
0037 n = sum(a);
0038 
0039 GRAPH_MAGIC.graphs{g.idx}.array = logical(ones(n));
0040 a = a(:)';
0041 aa = [0,cumsum(a)];
0042 for k=1:length(a)
0043     GRAPH_MAGIC.graphs{g.idx}.array(aa(k)+1:aa(k+1),aa(k)+1:aa(k+1))=0;
0044 end
0045 
0046

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