FairRoot/PandaRoot
Tools.h
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1 /* Copyright 2008-2010, Technische Universitaet Muenchen,
2  Authors: Christian Hoeppner & Sebastian Neubert & Johannes Rauch
3 
4  This file is part of GENFIT.
5 
6  GENFIT is free software: you can redistribute it and/or modify
7  it under the terms of the GNU Lesser General Public License as published
8  by the Free Software Foundation, either version 3 of the License, or
9  (at your option) any later version.
10 
11  GENFIT is distributed in the hope that it will be useful,
12  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  GNU Lesser General Public License for more details.
15 
16  You should have received a copy of the GNU Lesser General Public License
17  along with GENFIT. If not, see <http://www.gnu.org/licenses/>.
18 */
19 
24 #ifndef genfit_Tools_h
25 #define genfit_Tools_h
26 
27 #include <TVectorD.h>
28 #include <TMatrixD.h>
29 #include <TMatrixDSym.h>
30 
34 namespace genfit {
35 namespace tools {
36 
40  void invertMatrix(const TMatrixDSym& mat, TMatrixDSym& inv, double* determinant = NULL);
43  void invertMatrix(TMatrixDSym& mat, double* determinant = NULL);
44 
48  bool transposedForwardSubstitution(const TMatrixD& R, TVectorD& b);
50  bool transposedForwardSubstitution(const TMatrixD& R, TMatrixD& b, int nCol);
52  bool transposedInvert(const TMatrixD& R, TMatrixD& inv);
53 
58  void QR(TMatrixD& A);
59 
65  void QR(TMatrixD& A, TVectorD& b);
66 
71 void safeAverage(const TMatrixDSym& C1, const TMatrixDSym& C2,
72  TMatrixDSym& result);
73 
74 } /* End of namespace tools */
75 } /* End of namespace genfit */
78 #endif // genfit_Tools_h
TTree * b
void QR(TMatrixD &A)
Replaces A with an upper right matrix connected to A by an orthongonal transformation. I.e., it computes R from a QR decomposition of A = QR, replacing A.
bool transposedForwardSubstitution(const TMatrixD &R, TVectorD &b)
Solves R^t x = b, replacing b with the solution for x. R is assumed to be upper diagonal.
void safeAverage(const TMatrixDSym &C1, const TMatrixDSym &C2, TMatrixDSym &result)
This averages the covariance matrices C1, C2 in a numerically stable way by using matrix square roots...
bool transposedInvert(const TMatrixD &R, TMatrixD &inv)
Inverts the transpose of the upper right matrix R into inv.
void invertMatrix(const TMatrixDSym &mat, TMatrixDSym &inv, double *determinant=NULL)
Invert a matrix, throwing an Exception when inversion fails. Optional calculation of determinant...
Double_t R
Definition: checkhelixhit.C:61
TMatrixT< double > TMatrixD
Definition: PndLmdDim.h:52