/usr/include/CLHEP/GenericFunctions/ClebschGordanCoefficientSet.hh is in libclhep-dev 2.1.4.1+dfsg-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | #ifndef _ClebschGordanCoefficientSet_h_
#define _ClebschGordanCoefficientSet_h_
#include <map>
#include <algorithm>
#include <cmath>
namespace Genfun {
class ClebschGordanCoefficientSet {
public:
double operator () (unsigned int l1, unsigned int l2, int m1, int m2, int L, int M) const;
private:
// Key used to optimize access (look up previously calcuated results).
class Key {
public:
inline Key(unsigned int xl1, unsigned int xl2, int xm1, int xm2, unsigned int xL):
l1(xl1),l2(xl2),m1(xm1),m2(xm2),L(xL) {}
inline bool operator < (const Key & o) const {
if ( l1!=o.l1) return l1<o.l1;
if ( l2!=o.l2) return l2<o.l2;
if ( m1!=o.m1) return m1<o.m1;
if ( m2!=o.m2) return m2<o.m2;
if ( L!=o.L ) return L<o.L;
return false;
}
inline bool operator== (const Key & o) const {
return l1==o.l1 && l2 == o.l2 && m1==o.m1 && m2==o.m2 && L == o.L;
}
private:
unsigned int l1;
unsigned l2;
int m1;
int m2;
unsigned int L;
// M=m1+m2;
};
mutable std::map<Key, double> coeff;
static double calcCoefficient(int l1, int l2, int L, int m1, int m2, int M);
};
inline double ClebschGordanCoefficientSet::operator () (unsigned int l1, unsigned int l2, int m1, int m2, int L, int M) const {
if ((m1+m2)!=M) return 0;
Key key(l1,l2,m1,m2,L);
std::map<Key,double>::iterator i=coeff.find(key),end=coeff.end();
if (i==end) {
double c = calcCoefficient(l1, l2, L, m1, m2,M);
coeff[key]=c;
return c;
}
return (*i).second;
}
}
#endif
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