* Interface to GiNaC's indices. */
/*
- * GiNaC Copyright (C) 1999-2000 Johannes Gutenberg University Mainz, Germany
+ * 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
#ifndef __GINAC_IDX_H__
#define __GINAC_IDX_H__
-#include <string>
-//#include <vector>
-#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
+ * 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)
-
-// member functions
+ GINAC_DECLARE_REGISTERED_CLASS(idx, basic)
- // default constructor, destructor, copy constructor assignment operator and helpers
+ // other constructors
+public:
+ /** 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:
- idx();
- ~idx();
- idx (const idx & other);
- const idx & operator=(const idx & other);
+ 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:
- void copy(const idx & 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(const string & n, bool cov=false);
- explicit idx(const char * n, bool cov=false);
- explicit idx(unsigned 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);}
+
+ // member variables
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;
+ 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:
- virtual bool is_co_contra_pair(const basic & other) const;
- virtual ex toggle_covariant(void) const;
+ /** 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:
+ void print(std::ostream & os, unsigned upper_precedence=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;
- void setname(const string & n) {name=n;}
- string getname(void) const {return name;}
+ /** Check whether the index is covariant. */
+ bool is_covariant(void) const {return covariant;}
+
+ /** Check whether the index is contravariant (not covariant). */
+ bool is_contravariant(void) const {return !covariant;}
- // member variables
+ /** 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 const 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<const idx &>(*e.bp);
}
-// global functions
+inline const varidx &ex_to_varidx(const ex & e)
+{
+ return static_cast<const varidx &>(*e.bp);
+}
+
+/** Check whether two indices form a dummy pair. */
+bool is_dummy_pair(const idx & i1, const idx & i2);
-// typedef vector<ex> exvector;
+/** 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,
- bool antisymmetric, 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__
git://www.ginac.de / ginac.git / blobdiff