#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 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)
// 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;}
- /** Get numeric value of index. Undefined for symbolic indices. */
- unsigned 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 index is covariant (not contravariant). */
+ /** 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:
+ 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);
+
+ // 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
+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;}
-private:
- std::string & autoname_prefix(void);
+ /** Make a new index with the same value but the opposite variance. */
+ ex toggle_variance(void) const;
// member variables
protected:
- unsigned serial; /**< Unique serial number for comparing symbolic indices */
- 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 */
};
+
// 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);
+
+/** 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__
git://www.ginac.de / ginac.git / blobdiff