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PdfFuncMathMore.h
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1 // @(#)root/mathmore:$Id$
2 // Authors: L. Moneta, A. Zsenei 08/2005
3 
4  /**********************************************************************
5  * *
6  * Copyright (c) 2004 ROOT Foundation, CERN/PH-SFT *
7  * *
8  * This library is free software; you can redistribute it and/or *
9  * modify it under the terms of the GNU General Public License *
10  * as published by the Free Software Foundation; either version 2 *
11  * of the License, or (at your option) any later version. *
12  * *
13  * This library is distributed in the hope that it will be useful, *
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of *
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
16  * General Public License for more details. *
17  * *
18  * You should have received a copy of the GNU General Public License *
19  * along with this library (see file COPYING); if not, write *
20  * to the Free Software Foundation, Inc., 59 Temple Place, Suite *
21  * 330, Boston, MA 02111-1307 USA, or contact the author. *
22  * *
23  **********************************************************************/
24 
25 
26 #ifndef ROOT_Math_PdfFuncMathMore
27 #define ROOT_Math_PdfFuncMathMore
28 
29 namespace ROOT {
30  namespace Math {
31 
32 
33  /**
34 
35  Probability density function of the non central \f$\chi^2\f$ distribution with \f$r\f$
36  degrees of freedom and the noon-central parameter \f$\lambda\f$
37 
38  \f[ p_r(x) = \frac{1}{\Gamma(r/2) 2^{r/2}} x^{r/2-1} e^{-x/2} \f]
39 
40  for \f$x \geq 0\f$.
41  For detailed description see
42  <A HREF="http://mathworld.wolfram.com/NoncentralChi-SquaredDistribution.html">
43  Mathworld</A>.
44 
45  @ingroup PdfFunc
46 
47  */
48 
49  double noncentral_chisquared_pdf(double x, double r, double lambda);
50 
51  } //end namespace Math
52 } // end namespace ROOT
53 
54 
55 // make a fake class to auto-load functions from MathMore
56 
57 namespace ROOT {
58  namespace Math {
59 
60  class MathMoreLib {
61 
62  public:
63 
64  // adding this method with force the auto-loading of the library
65  static void Load();
66  };
67 
69  }
70 
71 }
72 
73 
74 
75 #endif // ROOT_Math_PdfFuncMathMore
VSD Structures.
Definition: StringConv.hxx:21
MathMoreLib MathMoreLibrary
Double_t x[n]
Definition: legend1.C:17
ROOT::R::TRInterface & r
Definition: Object.C:4
double noncentral_chisquared_pdf(double x, double r, double lambda)
Probability density function of the non central distribution with degrees of freedom and the noon-c...
Namespace for new Math classes and functions.