## Contents

```
function [t,d,w] = tricnt(G,d,matlabbgl)
```

%TRICNT Count number of triangles per vertex in a simple, undirected graph % % T = TRICNT(G) takes a sparse adjacency matrix G and computes the number % of triangles per vertex. Note taht there is no error checking on G. It % is up to the user to ensure that G is symmetric, has only 0/1 entries % (but *not* binary), and has no entries on the diagonal. % % T = TRICNT(G,D) takes a second argument which is the degree per vertex % and does not recalculate it. % % T = TRICNT(G,D,true) uses the clustering_coefficients from MATLAB_BGL. % This assumes that this package is installed and in the path. % % [T,D,W] = TRICNT(G) also returns the degree and number of wedges per % vertex. % % NOTE: This is an interface to the MEX function provided by % tricnt_mex.c, unless the clustering_coefficients function from % MATLAB_BGL is used. % % See also CCPERDEG. % % 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.

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if ~exist('matlabbgl','var') matlabbgl = false; end if ~exist('d','var') || isempty(d) d = full(sum(G,2)); end w = d.*(d-1)/2; if (matlabbgl) if ~exist('clustering_coefficients.m','file') error('Must install MATLAB_BGL toolbox'); end options.undirected = 1; options.unweighted = 1; cc = clustering_coefficients(G,options); t = round(w.*cc); else t = tricnt_mex(G); end