Contents

function G = edges2graph(E,nnodes)
%EDGES2GRAPH Create an undirected, simple graph from edge list.
%
%   G = EDGES2GRAPH(E) creates an adjaceny matrix for the graph where
%   E(k,1) and E(k,2) specifies the kth edge. All edges are treated as
%   undirected. Duplicate edges are removed. Loops are removed.
%
%   G = EDGES2GRAPH(E,N) specifies the number of number of nodes in the
%   graph.
%
% Tamara G. Kolda, Ali Pinar, and others, FEASTPACK v1.1, Sandia National
% Laboratories, SAND2013-4136W, http://www.sandia.gov/~tgkolda/feastpack/,
% January 2014

License

Copyright (c) 2014, Sandia National Laboratories All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

  1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
  2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

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if ~exist('nnodes','var')
    nnodes = max(E(:));
else
    % Error checking only
    tmp = max(E(:));
    if (tmp > nnodes)
        fprintf('Highest index in E is %d, but N = %d', tmp, nnodes);
    end
end

ii = E(:,1);
jj = E(:,2);
G = spones(sparse([ii;jj],[jj;ii],1,nnodes,nnodes));
G = spdiags(zeros(nnodes,1),0,G);