36 lines
1.4 KiB
Matlab
36 lines
1.4 KiB
Matlab
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% Return the list of edges for varying graph representation types
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% Inputs: graph structure (matrix or cell or struct) and type of structure (string)
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% Outputs: edge list, mx3 matrix, where the third column is edge weight
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%
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% Note 1: 'type' can be: 'adjacency','edgelist','adjlist', 'incidence'
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% Note 2: symmetric edges will appear twice, also in undirected graphs, (i.e. [n1,n2] and [n2,n1])
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%
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% Example representations of a directed triangle: 1->2->3->1
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% 'adjacency' - [0 1 0; 0 0 1; 1 0 0]
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% 'adjlist' - {1: [2], 2: [3], 3: [1]}
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% 'edgelist' - [1 2; 2 3; 3 1] or [1 2 1; 2 3 1; 3 1 1] (1 is the edge weight)
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% 'incidence' - [-1 0 1
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% 1 -1 0
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% 0 1 -1]
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%
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% Other routines used: adj2edgeL.m, adjL2edgeL.m, inc2edgeL.m
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% GB: last updated, Sep 18 2012
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function edges = getEdges(graph,type)
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if strcmp(type,'adjacency')
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edges=sortrows(adj2edgeL(graph));
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elseif strcmp(type,'edgelist')
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edges=graph; % the graph structure is the edge list
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elseif strcmp(type,'adjlist')
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edges=sortrows(adjL2edgeL(graph));
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elseif strcmp(type,'incidence')
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edges=sortrows(inc2edgeL(graph));
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else
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printf('getEdges(): "type" input can only be\n "adj" (adjacency, nxn matrix)\n, "edgelist" (mx2 or mx3 matrix)\n, "adjlist" (list, nx1 cell)\n or "inc" incidence (nxm matrix)\n')
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edges = 'invalid graph type';
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end
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