Description of laplacian

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laplacian

PURPOSE

laplacian(g) --- get the Laplacian matrix of g

SYNOPSIS

function m = laplacian(g)

DESCRIPTION

 laplacian(g) --- get the Laplacian matrix of g
 equal to D-A where A is the adjacency matrix and D is a diagonal matrix
 of the degrees of the vertices.

CROSS-REFERENCE INFORMATION

This function calls:

• deg deg: degree of a vertex or degree sequence
• matrix matrix(g) --- return (a copy of) the adjacency matrix of g
• nv nv(g) --- number of vertices in g

This function is called by:

• resistance R = resistance(g) --- calculate resistances between vertices
• split part = split(g) --- partition the vertices of g into two subsets

SOURCE CODE

0001 function m = laplacian(g)
0002 % laplacian(g) --- get the Laplacian matrix of g
0003 % equal to D-A where A is the adjacency matrix and D is a diagonal matrix
0004 % of the degrees of the vertices.
0005 
0006 
0007 n = nv(g);
0008 d = deg(g);
0009 m = -matrix(g);
0010 for k=1:n
0011     m(k,k) = d(k);
0012 end

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