Description of isconnected

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isconnected

PURPOSE

isconnected(g) --- test if g is a connected graph

SYNOPSIS

function yn = isconnected(g)

DESCRIPTION

 isconnected(g) --- test if g is a connected graph

CROSS-REFERENCE INFORMATION

This function calls:

• nv nv(g) --- number of vertices in g

This function is called by:

• prufer prufer --- convert a tree to/from its Prufer code
• resistance R = resistance(g) --- calculate resistances between vertices
• springxy springxy(g) --- find a spring embedding of g

SOURCE CODE

0001 function yn = isconnected(g)
0002 % isconnected(g) --- test if g is a connected graph
0003 
0004 global GRAPH_MAGIC
0005 
0006 n = nv(g);
0007 if (n==0) 
0008     yn = 1;
0009     return
0010 end
0011 
0012 x = zeros(n,1);
0013 x(1) = 1;
0014 while(1)
0015     y = x;
0016     x = GRAPH_MAGIC.graphs{g.idx}.array*x + x;
0017     x = double(x>0);
0018     if (x==y)
0019         break
0020     end
0021 end
0022 
0023 yn = sum(x)==n;

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