X-Git-Url: https://ginac.de/ginac.git//ginac.git?a=blobdiff_plain;ds=sidebyside;f=ginac%2Fidx.h;h=ea885feef1d56c86f043b328b5b4f279c010fbe7;hb=08d556dc3ac3fbf2b0ad3acd37016a1f925d7c02;hp=2941fa96724fba23cfecdc36e9bca983757190d5;hpb=7cbe7effc515e4575b4d1fd1d6d75f0148eb8a89;p=ginac.git diff --git a/ginac/idx.h b/ginac/idx.h index 2941fa96..ea885fee 100644 --- a/ginac/idx.h +++ b/ginac/idx.h @@ -23,104 +23,125 @@ #ifndef __GINAC_IDX_H__ #define __GINAC_IDX_H__ -#include -//#include -#include "basic.h" #include "ex.h" -#ifndef NO_NAMESPACE_GINAC namespace GiNaC { -#endif // ndef NO_NAMESPACE_GINAC -/** This class holds one index of an indexed object. Indices can be symbolic - * (e.g. "mu", "i") or numeric (unsigned integer), and they can be contravariant - * (the default) or covariant. */ +/** This class holds one index of an indexed object. Indices can + * theoretically consist of any symbolic expression but they are usually + * only just a symbol (e.g. "mu", "i") or numeric (integer). Indices belong + * to a space with a certain numeric or symbolic dimension. */ class idx : public basic { GINAC_DECLARE_REGISTERED_CLASS(idx, basic) - // default constructor, destructor, copy constructor assignment operator and helpers -public: - idx(); - ~idx(); - idx (const idx & other); - const idx & operator=(const idx & other); -protected: - void copy(const idx & other); - void destroy(bool call_parent); - // other constructors public: - explicit idx(bool cov); - explicit idx(const std::string & n, bool cov=false); - explicit idx(const char * n, bool cov=false); - explicit idx(unsigned v, bool cov=false); + /** Construct index with given value and dimension. + * + * @param v Value of index (numeric or symbolic) + * @param dim Dimension of index space (numeric or symbolic) + * @return newly constructed index */ + explicit idx(const ex & v, const ex & dim); // functions overriding virtual functions from bases classes public: - basic * duplicate() const; void printraw(std::ostream & os) const; void printtree(std::ostream & os, unsigned indent) const; void print(std::ostream & os, unsigned upper_precedence=0) const; bool info(unsigned inf) const; protected: - int compare_same_type(const basic & other) const; - bool is_equal_same_type(const basic & other) const; - unsigned calchash(void) const; ex subs(const lst & ls, const lst & lr) const; - // new virtual functions which can be overridden by derived classes + // new virtual functions in this class public: - virtual bool is_co_contra_pair(const basic & other) const; - virtual ex toggle_covariant(void) const; + /** Check whether the index forms a dummy index pair with another index + * of the same type. */ + virtual bool is_dummy_pair_same_type(const basic & other) const; // non-virtual functions in this class public: - /** Check whether index is symbolic (not numeric). */ - bool is_symbolic(void) const {return symbolic;} + /** Get value of index. */ + ex get_value(void) const {return value;} + + /** Check whether the index is numeric. */ + bool is_numeric(void) const {return is_ex_exactly_of_type(value, numeric);} + + /** Check whether the index is symbolic. */ + bool is_symbolic(void) const {return !is_ex_exactly_of_type(value, numeric);} + + /** Get dimension of index space. */ + ex get_dim(void) const {return dim;} + + /** Check whether the dimension is numeric. */ + bool is_dim_numeric(void) const {return is_ex_exactly_of_type(dim, numeric);} + + /** Check whether the dimension is symbolic. */ + bool is_dim_symbolic(void) const {return !is_ex_exactly_of_type(dim, numeric);} + +protected: + ex value; /**< Expression that constitutes the index (numeric or symbolic name) */ + ex dim; /**< Dimension of space (can be symbolic or numeric) */ +}; + + +/** This class holds an index with a variance (co- or contravariant). There + * is an associated metric tensor that can be used to raise/lower indices. */ +class varidx : public idx +{ + GINAC_DECLARE_REGISTERED_CLASS(varidx, idx) + + // other constructors +public: + /** Construct index with given value, dimension and variance. + * + * @param v Value of index (numeric or symbolic) + * @param dim Dimension of index space (numeric or symbolic) + * @param covariant Make covariant index (default is contravariant) + * @return newly constructed index */ + varidx(const ex & v, const ex & dim, bool covariant = false); - /** Get numeric value of index. Undefined for symbolic indices. */ - unsigned get_value(void) const {return value;} + // functions overriding virtual functions from bases classes +public: + void print(std::ostream & os, unsigned upper_precedence=0) const; + bool is_dummy_pair_same_type(const basic & other) const; - /** Check whether index is covariant (not contravariant). */ + // non-virtual functions in this class +public: + /** Check whether the index is covariant. */ bool is_covariant(void) const {return covariant;} - void setname(const std::string & n) {name=n;} - std::string getname(void) const {return name;} + /** Check whether the index is contravariant (not covariant). */ + bool is_contravariant(void) const {return !covariant;} + + /** Make a new index with the same value but the opposite variance. */ + ex toggle_variance(void) const; // member variables protected: - unsigned serial; - bool symbolic; /**< Is index symbolic? */ - std::string name; /**< Symbolic name (if symbolic == true) */ - unsigned value; /**< Numeric value (if symbolic == false) */ - static unsigned next_serial; - bool covariant; /**< x_mu, default is contravariant: x~mu */ + bool covariant; /**< x.mu, default is contravariant: x~mu */ }; -// global constants - -extern const idx some_idx; -extern const std::type_info & typeid_idx; // utility functions -inline const idx &ex_to_idx(const ex &e) +inline const idx &ex_to_idx(const ex & e) { return static_cast(*e.bp); } -// global functions +inline const varidx &ex_to_varidx(const ex & e) +{ + return static_cast(*e.bp); +} + +/** Check whether two indices form a dummy pair. */ +bool is_dummy_pair(const idx & i1, const idx & i2); + +/** Check whether two expressions form a dummy index pair. */ +bool is_dummy_pair(const ex & e1, const ex & e2); -int canonicalize_indices(exvector & iv, bool antisymmetric=false); -exvector idx_intersect(const exvector & iv1, const exvector & iv2); -ex permute_free_index_to_front(const exvector & iv3, const exvector & iv2, int * sig); -unsigned subs_index_in_exvector(exvector & v, const ex & is, const ex & ir); -ex subs_indices(const ex & e, const exvector & idxv_contra, const exvector & idxv_co); -unsigned count_index(const ex & e, const ex & i); -#ifndef NO_NAMESPACE_GINAC } // namespace GiNaC -#endif // ndef NO_NAMESPACE_GINAC #endif // ndef __GINAC_IDX_H__