mat1  --  Typical circuit matrix, somewhat ill-conditioned.
23	real
1 1 0.0201303
1 6 -0.0108325
1 19 -0.00992221
2 2 0.00196826
2 6 -7.00819e-05
2 16 -0.000149258
3 3 0.00233598
3 6 -6.89538e-05
3 13 -3.81701e-05
3 14 -0.000161645
4 4 0.00181074
4 6 -7.11072e-05
5 5 0.00193524
5 6 -8.35603e-05
5 8 -0.000160605
6 1 -1.72443e-05
6 2 -9.41688e-05
6 3 -4.87603e-05
6 4 -9.88527e-05
6 5 -1.01501e-05
6 6 0.0237867
7 7 0.0020023
7 20 -0.002
8 5 -6.08416e-05
8 8 0.000306666
8 11 3.52493e-05
9 9 0.00012008
10 10 0.00200237
10 22 -0.002
11 11 9.74511e-05
12 12 0.000182758
13 3 -0.000458012
13 13 0.00205898
13 21 -0.002
14 3 -4.65368e-05
14 14 0.000305252
14 17 3.7642e-05
15 15 0.00012008
16 2 -0.000156934
16 16 0.00217081
16 23 -0.002
17 17 9.5915e-05
18 18 0.000182758
19 1 -0.00413682
19 19 0.0189592
20 7 -0.002
20 20 10.0037
20 21 -10
21 13 -0.002
21 20 -10
21 21 10.002
22 10 -0.002
22 22 10.0037
22 23 -10
23 16 -0.002
23 22 -10
23 23 10.002
0  0  0.0
-2.57565e-05
-4.48769e-07
-4.13483e-06
-1.01714e-06
-1.37342e-05
2.90276e-07
1.51576e-09
-1.56322e-07
0
5.2198e-08
0
0
-4.63536e-07
1.99061e-06
0
1.95645e-06
0
0
3.74634e-05
6.29115e-06
-4.69183e-06
-3.57397e-06
1.88248e-06