Table 4. The cohesive subgroup density matrix of cultivated land utilization ecological efficiency network.

Density matrix					Like matrix
Subgroup	1	2	3	4	1	2	3	4
1	0.708	0.295	0.006	0.004	1	1	0	0
2	0.357	0.548	0.157	0.071	1	1	0	0
3	0.031	0.214	0.456	0.029	0	1	1	1
4	0.009	0.031	0.050	0.176	0	0	0	0