/** @file clifford.cpp
*
- * Implementation of GiNaC's clifford objects.
- * No real implementation yet, to be done. */
+ * Implementation of GiNaC's clifford algebra (Dirac gamma) objects. */
/*
- * 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
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
-#include <string>
-
#include "clifford.h"
#include "ex.h"
+#include "idx.h"
#include "ncmul.h"
-#include "utils.h"
+#include "archive.h"
#include "debugmsg.h"
+#include "utils.h"
+
+#include <stdexcept>
-#ifndef NO_GINAC_NAMESPACE
namespace GiNaC {
-#endif // ndef NO_GINAC_NAMESPACE
+
+GINAC_IMPLEMENT_REGISTERED_CLASS(clifford, indexed)
+GINAC_IMPLEMENT_REGISTERED_CLASS(diracone, tensor)
+GINAC_IMPLEMENT_REGISTERED_CLASS(diracgamma, tensor)
//////////
// default constructor, destructor, copy constructor assignment operator and helpers
//////////
-// public
-
clifford::clifford()
{
- debugmsg("clifford default constructor",LOGLEVEL_CONSTRUCT);
- serial=next_serial++;
- name=autoname_prefix()+ToString(serial);
- tinfo_key=TINFO_clifford;
+ debugmsg("clifford default constructor", LOGLEVEL_CONSTRUCT);
+ tinfo_key = TINFO_clifford;
}
-clifford::~clifford()
-{
- debugmsg("clifford destructor",LOGLEVEL_DESTRUCT);
- destroy(0);
-}
+DEFAULT_COPY(clifford)
+DEFAULT_DESTROY(clifford)
+DEFAULT_CTORS(diracone)
+DEFAULT_CTORS(diracgamma)
-clifford::clifford(const clifford & other)
+//////////
+// other constructors
+//////////
+
+/** Construct object with one Lorentz index. This constructor is for internal
+ * use only. Use the dirac_gamma() function instead.
+ * @see dirac_gamma */
+clifford::clifford(const ex & b, const ex & mu) : inherited(b, mu)
{
- debugmsg("clifford copy constructor",LOGLEVEL_CONSTRUCT);
- copy (other);
+ debugmsg("clifford constructor from ex,ex", LOGLEVEL_CONSTRUCT);
+ GINAC_ASSERT(is_ex_of_type(mu, varidx));
+ tinfo_key = TINFO_clifford;
}
-const clifford & clifford::operator=(const clifford & other)
+/** Construct object without any indices. This constructor is for internal
+ * use only. Use the dirac_one() function instead.
+ * @see dirac_one */
+clifford::clifford(const ex & b) : inherited(b)
{
- debugmsg("clifford operator=",LOGLEVEL_ASSIGNMENT);
- if (this != &other) {
- destroy(1);
- copy(other);
- }
- return *this;
+ debugmsg("clifford constructor from ex", LOGLEVEL_CONSTRUCT);
+ tinfo_key = TINFO_clifford;
}
-// protected
-
-void clifford::copy(const clifford & other)
+clifford::clifford(const exvector & v, bool discardable) : inherited(indexed::unknown, v, discardable)
{
- indexed::copy(other);
- name=other.name;
- serial=other.serial;
+ debugmsg("clifford constructor from exvector", LOGLEVEL_CONSTRUCT);
+ tinfo_key = TINFO_clifford;
}
-void clifford::destroy(bool call_parent)
+clifford::clifford(exvector * vp) : inherited(indexed::unknown, vp)
{
- if (call_parent) {
- indexed::destroy(call_parent);
- }
+ debugmsg("clifford constructor from exvector *", LOGLEVEL_CONSTRUCT);
+ tinfo_key = TINFO_clifford;
}
//////////
-// other constructors
+// archiving
//////////
-// public
-
-clifford::clifford(const string & initname)
-{
- debugmsg("clifford constructor from string",LOGLEVEL_CONSTRUCT);
- name=initname;
- serial=next_serial++;
- tinfo_key=TINFO_clifford;
-}
+DEFAULT_ARCHIVING(clifford)
+DEFAULT_ARCHIVING(diracone)
+DEFAULT_ARCHIVING(diracgamma)
//////////
// functions overriding virtual functions from bases classes
//////////
-// public
-
-basic * clifford::duplicate() const
-{
- debugmsg("clifford duplicate",LOGLEVEL_DUPLICATE);
- return new clifford(*this);
-}
-
-void clifford::printraw(ostream & os) const
-{
- debugmsg("clifford printraw",LOGLEVEL_PRINT);
- os << "clifford(" << "name=" << name << ",serial=" << serial
- << ",indices=";
- printrawindices(os);
- os << ",hash=" << hashvalue << ",flags=" << flags << ")";
-}
-
-void clifford::printtree(ostream & os, unsigned indent) const
-{
- debugmsg("clifford printtree",LOGLEVEL_PRINT);
- os << string(indent,' ') << name << " (clifford): "
- << "serial=" << serial << ","
- << seq.size() << "indices=";
- printtreeindices(os,indent);
- os << ", hash=" << hashvalue << " (0x" << hex << hashvalue << dec << ")"
- << ", flags=" << flags << endl;
-}
-
-void clifford::print(ostream & os, unsigned upper_precedence) const
+int clifford::compare_same_type(const basic & other) const
{
- debugmsg("clifford print",LOGLEVEL_PRINT);
- os << name;
- printindices(os);
-}
-
-void clifford::printcsrc(ostream & os, unsigned type, unsigned upper_precedence) const
+ return inherited::compare_same_type(other);
+}
+
+DEFAULT_COMPARE(diracone)
+DEFAULT_COMPARE(diracgamma)
+DEFAULT_PRINT(diracone, "ONE")
+DEFAULT_PRINT(diracgamma, "gamma")
+
+/** Contraction of a gamma matrix with something else. */
+bool diracgamma::contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const
+{
+ GINAC_ASSERT(is_ex_of_type(*self, indexed));
+ GINAC_ASSERT(is_ex_of_type(*other, indexed));
+ GINAC_ASSERT(is_ex_of_type(self->op(0), diracgamma));
+
+ if (is_ex_of_type(other->op(0), diracgamma)) {
+
+ ex dim = ex_to_idx(self->op(1)).get_dim();
+
+ // gamma~mu*gamma.mu = dim*ONE
+ if (other - self == 1) {
+ *self = dim;
+ *other = dirac_one();
+ return true;
+
+ // gamma~mu*gamma~alpha*gamma.mu = (2-dim)*gamma~alpha
+ } else if (other - self == 2
+ && is_ex_of_type(self[1], clifford)) {
+ *self = 2 - dim;
+ *other = _ex1();
+ return true;
+
+ // gamma~mu*gamma~alpha*gamma~beta*gamma.mu = 4*g~alpha~beta+(dim-4)*gamam~alpha*gamma~beta
+ } else if (other - self == 3
+ && is_ex_of_type(self[1], clifford)
+ && is_ex_of_type(self[2], clifford)) {
+ *self = 4 * metric_tensor(self[1].op(1), self[2].op(1)) * dirac_one() + (dim - 4) * self[1] * self[2];
+ self[1] = _ex1();
+ self[2] = _ex1();
+ *other = _ex1();
+ return true;
+
+ // gamma~mu*gamma~alpha*gamma~beta*gamma~delta*gamma.mu = -2*gamma~delta*gamma~beta*gamma~alpha+(4-dim)*gamma~alpha*gamma~beta*gamma~delta
+ } else if (other - self == 4
+ && is_ex_of_type(self[1], clifford)
+ && is_ex_of_type(self[2], clifford)
+ && is_ex_of_type(self[3], clifford)) {
+ *self = -2 * self[3] * self[2] * self[1] + (4 - dim) * self[1] * self[2] * self[3];
+ self[1] = _ex1();
+ self[2] = _ex1();
+ self[3] = _ex1();
+ *other = _ex1();
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/** Perform automatic simplification on noncommutative product of clifford
+ * objects. This removes superfluous ONEs. */
+ex clifford::simplify_ncmul(const exvector & v) const
{
- debugmsg("clifford print csrc",LOGLEVEL_PRINT);
- print(os,upper_precedence);
-}
+ exvector s;
+ s.reserve(v.size());
-bool clifford::info(unsigned inf) const
-{
- return indexed::info(inf);
-}
+ exvector::const_iterator it = v.begin(), itend = v.end();
+ while (it != itend) {
+ if (!is_ex_of_type(it->op(0), diracone))
+ s.push_back(*it);
+ it++;
+ }
-// protected
-
-int clifford::compare_same_type(const basic & other) const
-{
- GINAC_ASSERT(other.tinfo() == TINFO_clifford);
- const clifford *o = static_cast<const clifford *>(&other);
- if (serial==o->serial) {
- return indexed::compare_same_type(other);
- }
- return serial < o->serial ? -1 : 1;
+ if (s.size() == 0)
+ return clifford(diracone());
+ else if (s.size() == v.size())
+ return simplified_ncmul(v);
+ else
+ return simplified_ncmul(s);
}
-ex clifford::simplify_ncmul(const exvector & v) const
+ex clifford::thisexprseq(const exvector & v) const
{
- return simplified_ncmul(v);
+ return clifford(v);
}
-unsigned clifford::calchash(void) const
+ex clifford::thisexprseq(exvector * vp) const
{
- hashvalue=golden_ratio_hash(golden_ratio_hash(0x55555556U ^
- golden_ratio_hash(tinfo_key) ^
- serial));
- setflag(status_flags::hash_calculated);
- return hashvalue;
+ return clifford(vp);
}
//////////
-// virtual functions which can be overridden by derived classes
-//////////
-
-// none
-
-//////////
-// non-virtual functions in this class
+// global functions
//////////
-void clifford::setname(const string & n)
+ex dirac_one(void)
{
- name=n;
+ return clifford(diracone());
}
-// private
-
-string & clifford::autoname_prefix(void)
+ex dirac_gamma(const ex & mu)
{
- static string * s=new string("clifford");
- return *s;
-}
-
-//////////
-// static member variables
-//////////
+ if (!is_ex_of_type(mu, varidx))
+ throw(std::invalid_argument("index of Dirac gamma must be of type varidx"));
-// private
-
-unsigned clifford::next_serial=0;
-
-//////////
-// global constants
-//////////
-
-const clifford some_clifford;
-const type_info & typeid_clifford=typeid(some_clifford);
+ return clifford(diracgamma(), mu);
+}
-#ifndef NO_GINAC_NAMESPACE
} // namespace GiNaC
-#endif // ndef NO_GINAC_NAMESPACE
git://www.ginac.de / ginac.git / blobdiff