I have a TMatrixD covMatrix like this:
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
-----------------------------------------------------------------------------------------------------
0 | 99.69 76.02 42.7 15.49 3.102 -11.61 -35.31 -75.52 -114.5
1 | 76.02 71.42 51.38 21.98 10.54 -8.492 -34.63 -80.02 -108.2
2 | 42.7 51.38 60.21 35.97 17.69 -6.457 -29.58 -74.37 -97.53
3 | 15.49 21.98 35.97 46.7 33.56 3.402 -23.46 -54.44 -79.2
4 | 3.102 10.54 17.69 33.56 49.77 28.94 -2.234 -48.03 -93.32
5 | -11.61 -8.492 -6.457 3.402 28.94 63.86 31.35 -26.88 -74.11
6 | -35.31 -34.63 -29.58 -23.46 -2.234 31.35 80.68 56.59 -43.41
7 | -75.52 -80.02 -74.37 -54.44 -48.03 -26.88 56.59 182 120.7
8 | -114.5 -108.2 -97.53 -79.2 -93.32 -74.11 -43.41 120.7 489.6
and I want to get its invert matrix by using Invert():
TMatrixD covInvert = covMatrix.Invert();
But the result is so strange:
| 0 | 1 | 2 | 3 | 4 | ...
----------------------------------------------------------------------
0 | 1.224e+12 1.224e+12 1.224e+12 1.224e+12 1.224e+12 ...
1 | 1.224e+12 1.224e+12 1.224e+12 1.224e+12 1.224e+12 ...
2 | 1.224e+12 1.224e+12 1.224e+12 1.224e+12 1.224e+12 ...
3 | 1.224e+12 1.224e+12 1.224e+12 1.224e+12 1.224e+12 ...
4 | 1.224e+12 1.224e+12 1.224e+12 1.224e+12 1.224e+12 ...
5 | 1.224e+12 1.224e+12 1.224e+12 1.224e+12 1.224e+12 ...
6 | 1.224e+12 1.224e+12 1.224e+12 1.224e+12 1.224e+12 ...
7 | 1.224e+12 1.224e+12 1.224e+12 1.224e+12 1.224e+12 ...
8 | 1.224e+12 1.224e+12 1.224e+12 1.224e+12 1.224e+12 ...
How can I get the correct invert matrix?
best regards
ROOT Version: v6_18_04d