power method e pagerank come funzioni esterne

functions/external/costruzioneMatrice.m

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+function A=costruzioneMatrice(G,p)
+% c = out-degree, r = in-degree
+[n,n] = size(G);
+c = sum(G,1);
+r = sum(G,2);
+
+% Scale column sums to be 1 (or 0 where there are no out links).
+
+k = find(c~=0);
+D = sparse(k,k,1./c(k),n,n);
+
+% Solve (I - p*G*D)*x = e
+
+e = ones(n,1);
+I = speye(n,n);
+
+%Conventional power method
+   z = ((1-p)*(c~=0) + (c==0))/n;
+   A = p*G*D + e*z;