* Interface to GiNaC's color (SU(3) Lie algebra) objects. */
/*
- * GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
+ * GiNaC Copyright (C) 1999-2002 Johannes Gutenberg University Mainz, Germany
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
/** This class holds a generator T_a or the unity element of the Lie algebra
* of SU(3), as used for calculations in quantum chromodynamics. A
- * representation label (an unsigned integer) is used to distinguish
- * elements from different Lie algebra representations (only objects with
- * the same label "interact" with each other). These objects implement an
- * abstract representation of the group, not a specific matrix
- * representation. The indices used for color objects should not have a
- * variance. */
+ * representation label (an unsigned 8-bit integer) is used to distinguish
+ * elements from different Lie algebras (objects with different labels
+ * commute). These objects implement an abstract representation of the
+ * group, not a specific matrix representation. The indices used for color
+ * objects should not have a variance. */
class color : public indexed
{
GINAC_DECLARE_REGISTERED_CLASS(color, indexed)
// other constructors
public:
- color(const ex & b, unsigned rl = 0);
- color(const ex & b, const ex & i1, unsigned rl = 0);
+ color(const ex & b, unsigned char rl = 0);
+ color(const ex & b, const ex & i1, unsigned char rl = 0);
// internal constructors
- color(unsigned rl, const exvector & v, bool discardable = false);
- color(unsigned rl, exvector * vp); // vp will be deleted
+ color(unsigned char rl, const exvector & v, bool discardable = false);
+ color(unsigned char rl, exvector * vp); // vp will be deleted
// functions overriding virtual functions from base classes
protected:
+ bool match_same_type(const basic & other) const;
ex simplify_ncmul(const exvector & v) const;
ex thisexprseq(const exvector & v) const;
ex thisexprseq(exvector * vp) const;
unsigned return_type(void) const { return return_types::noncommutative; }
- unsigned return_type_tinfo(void) const { return TINFO_color; }
+ unsigned return_type_tinfo(void) const { return TINFO_color + representation_label; }
+
+ // non-virtual functions in this class
+public:
+ unsigned char get_representation_label(void) const {return representation_label;}
// member variables
private:
- unsigned representation_label; /**< Representation label to distinguish independent color matrices coming from separated fermion lines */
+ unsigned char representation_label; /**< Representation label to distinguish independent color matrices coming from separated fermion lines */
};
{
GINAC_DECLARE_REGISTERED_CLASS(su3one, tensor)
- // functions overriding virtual functions from bases classes
+ // functions overriding virtual functions from base classes
public:
- void print(std::ostream & os, unsigned upper_precedence=0) const;
+ void print(const print_context & c, unsigned level = 0) const;
};
/** This class represents an su(3) generator. */
{
GINAC_DECLARE_REGISTERED_CLASS(su3t, tensor)
- // functions overriding virtual functions from bases classes
+ // functions overriding virtual functions from base classes
public:
- void print(std::ostream & os, unsigned upper_precedence=0) const;
+ void print(const print_context & c, unsigned level = 0) const;
+ bool contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const;
};
/** This class represents the tensor of antisymmetric su(3) structure
{
GINAC_DECLARE_REGISTERED_CLASS(su3f, tensor)
- // functions overriding virtual functions from bases classes
+ // functions overriding virtual functions from base classes
public:
- void print(std::ostream & os, unsigned upper_precedence=0) const;
+ void print(const print_context & c, unsigned level = 0) const;
ex eval_indexed(const basic & i) const;
bool contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const;
};
{
GINAC_DECLARE_REGISTERED_CLASS(su3d, tensor)
- // functions overriding virtual functions from bases classes
+ // functions overriding virtual functions from base classes
public:
- void print(std::ostream & os, unsigned upper_precedence=0) const;
+ void print(const print_context & c, unsigned level = 0) const;
ex eval_indexed(const basic & i) const;
bool contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const;
};
// global functions
-inline const color &ex_to_color(const ex &e)
+
+/** Specialization of is_exactly_a<color>(obj) for color objects. */
+template<> inline bool is_exactly_a<color>(const basic & obj)
{
- return static_cast<const color &>(*e.bp);
+ return obj.tinfo()==TINFO_color;
}
-
/** Create the su(3) unity element. This is an indexed object, although it
* has no indices.
*
* @param rl Representation label
* @return newly constructed unity element */
-ex color_ONE(unsigned rl = 0);
+ex color_ONE(unsigned char rl = 0);
/** Create an su(3) generator.
*
* @param a Index
* @param rl Representation label
* @return newly constructed unity generator */
-ex color_T(const ex & a, unsigned rl = 0);
+ex color_T(const ex & a, unsigned char rl = 0);
/** Create an su(3) antisymmetric structure constant.
*
/** This returns the linear combination d.a.b.c+I*f.a.b.c. */
ex color_h(const ex & a, const ex & b, const ex & c);
+/** Calculate the trace of an expression containing color objects with a
+ * specified representation label.
+ *
+ * @param e Expression to take the trace of
+ * @param rl Representation label */
+ex color_trace(const ex & e, unsigned char rl = 0);
+
} // namespace GiNaC