/usr/include/CLHEP/GenericFunctions/CubicSplinePolynomial.icc is in libclhep-dev 2.1.4.1+dfsg-1.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 | // -*- C++ -*-
// $Id:
#include "CLHEP/Matrix/Matrix.h"
#include "CLHEP/Matrix/Vector.h"
#include <cassert>
#include <cmath>
#include <cfloat>
namespace Genfun {
FUNCTION_OBJECT_IMP(CubicSplinePolynomial)
class CubicSplinePolynomial::Clockwork {
public:
bool stale;
mutable CLHEP::HepMatrix A;
mutable CLHEP::HepVector V;
mutable CLHEP::HepVector Q;
std::vector<std::pair<double,double> > xPoints;
inline void computeSlopes() const {
unsigned int N=xPoints.size()-1;
A=CLHEP::HepMatrix(N+1,N+1,0);
V=CLHEP::HepVector(N+1,0);
// First take care of the "normal elements, i=1,N-1;
for (unsigned int i=1;i<N;i++) {
double dxPlus = xPoints[i+1].first -xPoints[i].first;
double dyPlus = xPoints[i+1].second-xPoints[i].second;
double mPlus = dyPlus/dxPlus;
double dx = xPoints[i].first -xPoints[i-1].first;
double dy = xPoints[i].second-xPoints[i-1].second;
double m = dy/dx;
A[i][i-1] = 1/dx;
A[i][i] = 2*(1/dxPlus + 1/dx);
A[i][i+1] = 1/dxPlus;
V[i] = 3*(m/dx+mPlus/dxPlus);
}
// Special treatment for i=0;
{
double dx = xPoints[1].first -xPoints[0].first;
double dy = xPoints[1].second-xPoints[0].second;
double m = dy/dx;
A[0][0] = 2.0;
A[0][1] = 1;
V[0] = 3*m;
}
// Special treatment for i=N-1;
{
double dx = xPoints[N].first -xPoints[N-1].first;
double dy = xPoints[N].second-xPoints[N-1].second;
double m = dy/dx;
A[N][N-1] = 1.0;
A[N][N] = 2.0;
V[N] = 3*m;
}
int err;
Q=A.inverse(err)*V;
}
};
inline CubicSplinePolynomial::CubicSplinePolynomial()
:Genfun::AbsFunction(),c(new Clockwork())
{
c->stale=true;
}
inline CubicSplinePolynomial::CubicSplinePolynomial(const CubicSplinePolynomial & right)
:Genfun::AbsFunction(),c(new Clockwork)
{
(*c) = (*right.c);
}
inline CubicSplinePolynomial::~CubicSplinePolynomial() {
delete c;
}
inline double CubicSplinePolynomial::operator() (double x) const {
unsigned int N=c->xPoints.size()-1;
if (c->xPoints.size()==0) return 0;
if (c->xPoints.size()==1) return c->xPoints[0].second;
if (c->stale) {
c->computeSlopes();
c->stale=false;
}
std::pair<double,double> fk(x,0);
std::vector<std::pair<double,double> >::const_iterator
n=std::lower_bound(c->xPoints.begin(),c->xPoints.end(),fk);
unsigned int i = n-c->xPoints.begin();
if (i==0) {
double x0=c->xPoints[0].first;
double y0=c->xPoints[0].second;
double m = c->Q[0];
return y0 + m*(x-x0);
}
else if (i==c->xPoints.size()) {
double x0=c->xPoints[N].first;
double y0=c->xPoints[N].second;
double m = c->Q[N];
return y0 + m*(x-x0);
}
else {
double x0=c->xPoints[i-1].first;
double x1=c->xPoints[i].first;
double y0=c->xPoints[i-1].second;
double y1=c->xPoints[i].second;
double dx = x1-x0;
double dy = y1-y0;
double m = dy/dx;
double Q0 = c->Q[i-1];
double Q1 = c->Q[i];
double a = (Q0-m)*dx;
double b = (m-Q1)*dx;
double t = (x-x0)/dx;
double u = (1-t);
return u*y0+t*y1 + t*u*(u*a + t*b);
}
}
inline void CubicSplinePolynomial::addPoint( double x, double y) {
c->xPoints.push_back(std::make_pair(x,y));
std::sort(c->xPoints.begin(),c->xPoints.end());
c->stale=true;
}
inline void CubicSplinePolynomial::getRange( double & min, double & max) const {
min=DBL_MAX, max=-DBL_MAX;
for (unsigned int i=0;i<c->xPoints.size();i++) {
min = std::min(min,c->xPoints[i].first);
max = std::max(max,c->xPoints[i].first);
}
}
} // namespace Genfun
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