The coordinates and corresponding values appear to be the row and column numbers. The 0, 1, 80 in his chart would mean row 0, column 1, value is 80.

The clusters sound like a list of all the separate connected subgraphs. Where there are 5 nodes in the example, and a pair of nodes are connected if(M,N)>=60 in the chart.

0 is connected to 1, 1 is connected to 2, and 2 to 3. 4 is connected to nothing, so you've got two independent sets of nodes; 0,1,2,3 vs 4.