The following data sets contain the input data that are used in this example:
data edge_data1; input i j; datalines; 1 2 2 9 3 4 3 5 5 6 6 7 7 9 8 9 ; data edge_data2; input i j; datalines; 1 4 2 3 4 6 4 7 5 6 6 8 7 8 7 10 9 10 10 11 ;