X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Ftensor.h;h=fb8185b6a3a118a4c2a49d20cd76f979034db264;hp=65c86c45bd5c703407980f390683f2a017f57a92;hb=f3b92d92e9b8ee71b189ddb2c7e27ed72b577732;hpb=50dc516836ac5e91f4f60a60b9a307b375247e7c diff --git a/ginac/tensor.h b/ginac/tensor.h index 65c86c45..fb8185b6 100644 --- a/ginac/tensor.h +++ b/ginac/tensor.h @@ -3,7 +3,7 @@ * Interface to GiNaC's special tensors. */ /* - * GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany + * GiNaC Copyright (C) 1999-2011 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 @@ -17,17 +17,17 @@ * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ -#ifndef __GINAC_TENSOR_H__ -#define __GINAC_TENSOR_H__ +#ifndef GINAC_TENSOR_H +#define GINAC_TENSOR_H #include "ex.h" +#include "archive.h" namespace GiNaC { - /** This class holds one of GiNaC's predefined special tensors such as the * delta and the metric tensors. They are represented without indices. * To attach indices to them, wrap them in an object of class indexed. */ @@ -35,13 +35,16 @@ class tensor : public basic { GINAC_DECLARE_REGISTERED_CLASS(tensor, basic) - // other constructors + // functions overriding virtual functions from base classes protected: - tensor(unsigned ti); + unsigned return_type() const { return return_types::noncommutative_composite; } - // functions overriding virtual functions from bases classes -protected: - unsigned return_type(void) const { return return_types::noncommutative_composite; } + // non-virtual functions in this class +public: + /** Replace dummy index in contracted-with object by the contracting + * object's second index (used internally for delta and metric tensor + * contractions. */ + bool replace_contr_index(exvector::iterator self, exvector::iterator other) const; }; @@ -51,12 +54,19 @@ class tensdelta : public tensor { GINAC_DECLARE_REGISTERED_CLASS(tensdelta, 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; + bool info(unsigned inf) const; ex eval_indexed(const basic & i) const; bool contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const; + + // non-virtual functions in this class +protected: + unsigned return_type() const { return return_types::commutative; } + void do_print(const print_context & c, unsigned level) const; + void do_print_latex(const print_latex & c, unsigned level) const; }; +GINAC_DECLARE_UNARCHIVER(tensdelta); /** This class represents a general metric tensor which can be used to @@ -66,12 +76,18 @@ class tensmetric : public tensor { GINAC_DECLARE_REGISTERED_CLASS(tensmetric, 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; + bool info(unsigned inf) const; ex eval_indexed(const basic & i) const; bool contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const; + + // non-virtual functions in this class +protected: + unsigned return_type() const { return return_types::commutative; } + void do_print(const print_context & c, unsigned level) const; }; +GINAC_DECLARE_UNARCHIVER(tensmetric); /** This class represents a Minkowski metric tensor. It has all the @@ -86,15 +102,47 @@ public: /** Construct Lorentz metric tensor with given signature. */ minkmetric(bool pos_sig); - // 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; + bool info(unsigned inf) const; ex eval_indexed(const basic & i) const; + /** Save (a.k.a. serialize) object into archive. */ + void archive(archive_node& n) const; + /** Read (a.k.a. deserialize) object from archive. */ + void read_archive(const archive_node& n, lst& syms); + // non-virtual functions in this class +protected: + unsigned return_type() const { return return_types::commutative; } + void do_print(const print_context & c, unsigned level) const; + void do_print_latex(const print_latex & c, unsigned level) const; + // member variables private: bool pos_sig; /**< If true, the metric is diag(-1,1,1...). Otherwise it is diag(1,-1,-1,...). */ }; +GINAC_DECLARE_UNARCHIVER(minkmetric); + + +/** This class represents an antisymmetric spinor metric tensor which + * can be used to raise/lower indices of 2-component Weyl spinors. If + * indexed, it must have exactly two indices of the same type which + * must be of class spinidx or a subclass and have dimension 2. */ +class spinmetric : public tensmetric +{ + GINAC_DECLARE_REGISTERED_CLASS(spinmetric, tensmetric) + + // functions overriding virtual functions from base classes +public: + bool info(unsigned inf) const; + ex eval_indexed(const basic & i) const; + bool contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const; + +protected: + void do_print(const print_context & c, unsigned level) const; + void do_print_latex(const print_latex & c, unsigned level) const; +}; +GINAC_DECLARE_UNARCHIVER(spinmetric); /** This class represents the totally antisymmetric epsilon tensor. If @@ -108,23 +156,31 @@ class tensepsilon : public tensor public: tensepsilon(bool minkowski, bool pos_sig); - // 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; + bool info(unsigned inf) const; ex eval_indexed(const basic & i) const; + bool contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const; + + /** Save (a.k.a. serialize) object into archive. */ + void archive(archive_node& n) const; + /** Read (a.k.a. deserialize) object from archive. */ + void read_archive(const archive_node& n, lst& syms); + // non-virtual functions in this class +protected: + unsigned return_type() const { return return_types::commutative; } + void do_print(const print_context & c, unsigned level) const; + void do_print_latex(const print_latex & c, unsigned level) const; // member variables private: bool minkowski; /**< If true, tensor is in Minkowski-type space. Otherwise it is in a Euclidean space. */ - bool pos_sig; /**< If true, the metric is assumed to be diag(-1,1,1...). Otherwise it is diag(1,-1,-1,...). This is only relevant if minkowski = true. */ + bool pos_sig; /**< If true, the metric is assumed to be diag(-1,1,1...). Otherwise it is diag(1,-1,-1,...). This is only relevant if minkowski = true. */ }; +GINAC_DECLARE_UNARCHIVER(tensepsilon); // utility functions -inline const tensor &ex_to_tensor(const ex &e) -{ - return static_cast(*e.bp); -} /** Create a delta tensor with specified indices. The indices must be of class * idx or a subclass. The delta tensor is always symmetric and its trace is @@ -155,6 +211,16 @@ ex metric_tensor(const ex & i1, const ex & i2); * @return newly constructed Lorentz metric tensor */ ex lorentz_g(const ex & i1, const ex & i2, bool pos_sig = false); +/** Create a spinor metric tensor with specified indices. The indices must be + * of class spinidx or a subclass and have a dimension of 2. The spinor + * metric is an antisymmetric tensor with a matrix representation of + * [[ [[ 0, 1 ]], [[ -1, 0 ]] ]]. + * + * @param i1 First index + * @param i2 Second index + * @return newly constructed spinor metric tensor */ +ex spinor_metric(const ex & i1, const ex & i2); + /** Create an epsilon tensor in a Euclidean space with two indices. The * indices must be of class idx or a subclass, and have a dimension of 2. * @@ -185,4 +251,4 @@ ex lorentz_eps(const ex & i1, const ex & i2, const ex & i3, const ex & i4, bool } // namespace GiNaC -#endif // ndef __GINAC_TENSOR_H__ +#endif // ndef GINAC_TENSOR_H