X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?a=blobdiff_plain;f=ginac%2Fidx.h;h=4981fefca4be57de67c165e6b2faeb57b12b7c54;hb=239e9d2ced6571dc0ca0d875234ec9d8df418827;hp=f32722f784e1fc6a4a1c56102a4f92b4fac6c9c3;hpb=66c0f31c678e6c1938d637636b230ea376c157c1;p=ginac.git diff --git a/ginac/idx.h b/ginac/idx.h index f32722f7..4981fefc 100644 --- a/ginac/idx.h +++ b/ginac/idx.h @@ -1,8 +1,9 @@ /** @file idx.h * - * Interface to GiNaC's indices. - * - * GiNaC Copyright (C) 1999 Johannes Gutenberg University Mainz, Germany + * Interface to GiNaC's indices. */ + +/* + * GiNaC Copyright (C) 1999-2001 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 @@ -22,85 +23,176 @@ #ifndef __GINAC_IDX_H__ #define __GINAC_IDX_H__ -#include -#include -#include +#include "ex.h" + +namespace GiNaC { + +/** 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 { -// member functions + GINAC_DECLARE_REGISTERED_CLASS(idx, basic) - // default constructor, destructor, copy constructor assignment operator and helpers + // other constructors public: - idx(); - ~idx(); - idx (idx const & other); - idx const & operator=(idx const & other); + /** 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: + void print(const print_context & c, unsigned level = 0) const; + bool info(unsigned inf) const; + unsigned nops() const; + ex & let_op(int i); protected: - void copy(idx const & other); - void destroy(bool call_parent); + ex subs(const lst & ls, const lst & lr) const; - // other constructors + // new virtual functions in this class public: - explicit idx(bool cov); - explicit idx(string const & n, bool cov=false); - explicit idx(char const * n, bool cov=false); - explicit idx(unsigned const v, bool cov=false); + /** 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; - // functions overriding virtual functions from bases classes + // non-virtual functions in this class public: - basic * duplicate() const; - void printraw(ostream & os) const; - void printtree(ostream & os, unsigned indent) const; - void print(ostream & os, unsigned upper_precedence=0) const; - bool info(unsigned inf) const; + /** 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: - int compare_same_type(basic const & other) const; - bool is_equal_same_type(basic const & other) const; - unsigned calchash(void) const; - ex subs(lst const & ls, lst const & lr) const; + ex value; /**< Expression that constitutes the index (numeric or symbolic name) */ + ex dim; /**< Dimension of space (can be symbolic or numeric) */ +}; - // new virtual functions which can be overridden by derived classes + +/** 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); + + // functions overriding virtual functions from bases classes public: - virtual bool is_co_contra_pair(basic const & other) const; - virtual ex toggle_covariant(void) const; + void print(const print_context & c, unsigned level = 0) const; + bool is_dummy_pair_same_type(const basic & other) const; - // non-virtual functions in this class + // non-virtual functions in this class public: - bool is_symbolic(void) const; - unsigned get_value(void) const; - bool is_covariant(void) const; + /** Check whether the index is covariant. */ + bool is_covariant(void) const {return covariant;} - // member variables + /** 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; - string name; - unsigned value; - 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 type_info const & typeid_idx; +// utility functions +inline const idx &ex_to_idx(const ex & e) +{ + return static_cast(*e.bp); +} + +inline const varidx &ex_to_varidx(const ex & e) +{ + return static_cast(*e.bp); +} -// macros +/** Check whether two indices form a dummy pair. */ +bool is_dummy_pair(const idx & i1, const idx & i2); -#define ex_to_idx(X) (static_cast(*(X).bp)) +/** Check whether two expressions form a dummy index pair. */ +bool is_dummy_pair(const ex & e1, const ex & e2); -// other functions +/** Given a vector of indices, split them into two vectors, one containing + * the free indices, the other containing the dummy indices (numeric + * indices are neither free nor dummy ones). + * + * @param it Pointer to start of index vector + * @param itend Pointer to end of index vector + * @param out_free Vector of free indices (returned, sorted) + * @param out_dummy Vector of dummy indices (returned, sorted) */ +void find_free_and_dummy(exvector::const_iterator it, exvector::const_iterator itend, exvector & out_free, exvector & out_dummy); + +/** Given a vector of indices, split them into two vectors, one containing + * the free indices, the other containing the dummy indices (numeric + * indices are neither free nor dummy ones). + * + * @param v Index vector + * @param out_free Vector of free indices (returned, sorted) + * @param out_dummy Vector of dummy indices (returned, sorted) */ +inline void find_free_and_dummy(const exvector & v, exvector & out_free, exvector & out_dummy) +{ + find_free_and_dummy(v.begin(), v.end(), out_free, out_dummy); +} + +/** Given a vector of indices, find the dummy indices. + * + * @param v Index vector + * @param out_dummy Vector of dummy indices (returned, sorted) */ +inline void find_dummy_indices(const exvector & v, exvector & out_dummy) +{ + exvector free_indices; + find_free_and_dummy(v.begin(), v.end(), free_indices, out_dummy); +} + +/** Count the number of dummy index pairs in an index vector. */ +inline unsigned count_dummy_indices(const exvector & v) +{ + exvector free_indices, dummy_indices; + find_free_and_dummy(v.begin(), v.end(), free_indices, dummy_indices); + return dummy_indices.size(); +} + +/** Count the number of dummy index pairs in an index vector. */ +inline unsigned count_free_indices(const exvector & v) +{ + exvector free_indices, dummy_indices; + find_free_and_dummy(v.begin(), v.end(), free_indices, dummy_indices); + return free_indices.size(); +} -typedef vector exvector; +/** Given two index vectors, find those indices that appear in the first + * vector but not in the second one (asymmetric set difference). */ +exvector index_set_difference(const exvector & set1, const exvector & set2); -int canonicalize_indices(exvector & iv, bool antisymmetric=false); -exvector idx_intersect(exvector const & iv1, exvector const & iv2); -ex permute_free_index_to_front(exvector const & iv3, exvector const & iv2, - bool antisymmetric, int * sig); -unsigned subs_index_in_exvector(exvector & v, ex const & is, ex const & ir); -ex subs_indices(ex const & e, exvector const & idxv_contra, - exvector const & idxv_co); -unsigned count_index(ex const & e, ex const & i); +} // namespace GiNaC #endif // ndef __GINAC_IDX_H__