covariance matrix symmetry test: surface noise
J N
100 300 3 0
10
0    0    0     0   0   0   0
0    1477 -1478 0   0   1   0
50   1478 -1467 0   0   1   0
100  1467 -1463 0   0   1   0
200  1463 -1458 0   0   1   0
500  1458 -1460 0   0   1   0
700  1460 -1470 0   0   1   0
1500 1470 -1496 0   0   1   0
3000 1600 400   0.2 0.5 1.8 0
3020 1800 600   0.1 0.2 2.0 0
9
2999 -2.5 -2.5 1 0
2999 -2.5 0 1 0
2999 -2.5 2.5 1 0
2999 0 -2.5 1 0
2999 0 0 1 0
2999 0 2.5 1 0
2999 2.5 -2.5 1 0
2999 2.5 0 1 0
2999 2.5 2.5 1 0
50 -50 0 0
1400 1e8
100 100 40