ROOT   Reference Guide
MnEigen.cxx
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1// @(#)root/minuit2:$Id$
2// Authors: M. Winkler, F. James, L. Moneta, A. Zsenei 2003-2005
3
4/**********************************************************************
5 * *
6 * Copyright (c) 2005 LCG ROOT Math team, CERN/PH-SFT *
7 * *
8 **********************************************************************/
9
10#include "Minuit2/MnEigen.h"
12#include "Minuit2/MnMatrix.h"
13
14namespace ROOT {
15
16 namespace Minuit2 {
17
18
19LAVector eigenvalues(const LASymMatrix&);
20
21std::vector<double> MnEigen::operator()(const MnUserCovariance& covar) const {
22 // wrapper to calculate eigenvalues of the covariance matrix using mneigen function
23
24 LASymMatrix cov(covar.Nrow());
25 for(unsigned int i = 0; i < covar.Nrow(); i++)
26 for(unsigned int j = i; j < covar.Nrow(); j++)
27 cov(i,j) = covar(i,j);
28
29 LAVector eigen = eigenvalues(cov);
30
31 std::vector<double> result(eigen.Data(), eigen.Data()+covar.Nrow());
32 return result;
33}
34
35 } // namespace Minuit2
36
37} // namespace ROOT
Class describing a symmetric matrix of size n.
Definition: LASymMatrix.h:51
const double * Data() const
Definition: LAVector.h:194
std::vector< double > operator()(const MnUserCovariance &) const
calculate the eigenvalues
Definition: MnEigen.cxx:21
Class containing the covariance matrix data represented as a vector of size n*(n+1)/2 Used to hide in...
LAVector eigenvalues(const LASymMatrix &mat)
VSD Structures.
Definition: StringConv.hxx:21