X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Findexed.cpp;h=edbc730037e9f10036e8fbadea2462af57bb85f0;hp=4eeb2db13600980050b2d7f7c91159e9e0044511;hb=ffad02322624ab79fdad1a23a3aa83cd67376151;hpb=0a1b35cf1e59c9e3aae33de8febaa1c8f4bbe630 diff --git a/ginac/indexed.cpp b/ginac/indexed.cpp index 4eeb2db1..edbc7300 100644 --- a/ginac/indexed.cpp +++ b/ginac/indexed.cpp @@ -1,9 +1,9 @@ /** @file indexed.cpp * - * Implementation of GiNaC's index carrying objects. */ + * Implementation of GiNaC's indexed expressions. */ /* - * GiNaC Copyright (C) 1999-2000 Johannes Gutenberg University Mainz, Germany + * GiNaC Copyright (C) 1999-2003 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 @@ -20,236 +20,325 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ -#include +#include +#include +#include #include "indexed.h" -#include "ex.h" #include "idx.h" -#include "debugmsg.h" +#include "add.h" +#include "mul.h" +#include "ncmul.h" +#include "power.h" +#include "relational.h" +#include "symmetry.h" +#include "operators.h" +#include "lst.h" +#include "archive.h" +#include "utils.h" -#ifndef NO_GINAC_NAMESPACE namespace GiNaC { -#endif // ndef NO_GINAC_NAMESPACE -GINAC_IMPLEMENT_REGISTERED_CLASS(indexed, exprseq) +GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(indexed, exprseq, + print_func(&indexed::do_print). + print_func(&indexed::do_print_latex). + print_func(&indexed::do_print_tree)) ////////// -// default constructor, destructor, copy constructor assignment operator and helpers +// default constructor ////////// -// public - -indexed::indexed() +indexed::indexed() : symtree(sy_none()) { - debugmsg("indexed default constructor",LOGLEVEL_CONSTRUCT); - tinfo_key=TINFO_indexed; + tinfo_key = TINFO_indexed; } -indexed::~indexed() +////////// +// other constructors +////////// + +indexed::indexed(const ex & b) : inherited(b), symtree(sy_none()) { - debugmsg("indexed destructor",LOGLEVEL_DESTRUCT); - destroy(0); + tinfo_key = TINFO_indexed; + validate(); } -indexed::indexed(indexed const & other) +indexed::indexed(const ex & b, const ex & i1) : inherited(b, i1), symtree(sy_none()) { - debugmsg("indexed copy constructor",LOGLEVEL_CONSTRUCT); - copy (other); + tinfo_key = TINFO_indexed; + validate(); } -indexed const & indexed::operator=(indexed const & other) +indexed::indexed(const ex & b, const ex & i1, const ex & i2) : inherited(b, i1, i2), symtree(sy_none()) { - debugmsg("indexed operator=",LOGLEVEL_ASSIGNMENT); - if (this != &other) { - destroy(1); - copy(other); - } - return *this; + tinfo_key = TINFO_indexed; + validate(); } -// protected - -void indexed::copy(indexed const & other) +indexed::indexed(const ex & b, const ex & i1, const ex & i2, const ex & i3) : inherited(b, i1, i2, i3), symtree(sy_none()) { - inherited::copy(other); + tinfo_key = TINFO_indexed; + validate(); } -void indexed::destroy(bool call_parent) +indexed::indexed(const ex & b, const ex & i1, const ex & i2, const ex & i3, const ex & i4) : inherited(b, i1, i2, i3, i4), symtree(sy_none()) { - if (call_parent) { - inherited::destroy(call_parent); - } + tinfo_key = TINFO_indexed; + validate(); } -////////// -// other constructors -////////// +indexed::indexed(const ex & b, const symmetry & symm, const ex & i1, const ex & i2) : inherited(b, i1, i2), symtree(symm) +{ + tinfo_key = TINFO_indexed; + validate(); +} -// public +indexed::indexed(const ex & b, const symmetry & symm, const ex & i1, const ex & i2, const ex & i3) : inherited(b, i1, i2, i3), symtree(symm) +{ + tinfo_key = TINFO_indexed; + validate(); +} -indexed::indexed(ex const & i1) : inherited(i1) +indexed::indexed(const ex & b, const symmetry & symm, const ex & i1, const ex & i2, const ex & i3, const ex & i4) : inherited(b, i1, i2, i3, i4), symtree(symm) { - debugmsg("indexed constructor from ex",LOGLEVEL_CONSTRUCT); - tinfo_key=TINFO_indexed; - GINAC_ASSERT(all_of_type_idx()); + tinfo_key = TINFO_indexed; + validate(); } -indexed::indexed(ex const & i1, ex const & i2) : inherited(i1,i2) +indexed::indexed(const ex & b, const exvector & v) : inherited(b), symtree(sy_none()) { - debugmsg("indexed constructor from ex,ex",LOGLEVEL_CONSTRUCT); - tinfo_key=TINFO_indexed; - GINAC_ASSERT(all_of_type_idx()); + seq.insert(seq.end(), v.begin(), v.end()); + tinfo_key = TINFO_indexed; + validate(); } -indexed::indexed(ex const & i1, ex const & i2, ex const & i3) - : inherited(i1,i2,i3) +indexed::indexed(const ex & b, const symmetry & symm, const exvector & v) : inherited(b), symtree(symm) { - debugmsg("indexed constructor from ex,ex,ex",LOGLEVEL_CONSTRUCT); - tinfo_key=TINFO_indexed; - GINAC_ASSERT(all_of_type_idx()); + seq.insert(seq.end(), v.begin(), v.end()); + tinfo_key = TINFO_indexed; + validate(); } -indexed::indexed(ex const & i1, ex const & i2, ex const & i3, ex const & i4) - : inherited(i1,i2,i3,i4) +indexed::indexed(const symmetry & symm, const exprseq & es) : inherited(es), symtree(symm) { - debugmsg("indexed constructor from ex,ex,ex,ex",LOGLEVEL_CONSTRUCT); - tinfo_key=TINFO_indexed; - GINAC_ASSERT(all_of_type_idx()); + tinfo_key = TINFO_indexed; } -indexed::indexed(exvector const & iv) : inherited(iv) +indexed::indexed(const symmetry & symm, const exvector & v, bool discardable) : inherited(v, discardable), symtree(symm) { - debugmsg("indexed constructor from exvector",LOGLEVEL_CONSTRUCT); - tinfo_key=TINFO_indexed; - GINAC_ASSERT(all_of_type_idx()); + tinfo_key = TINFO_indexed; } -indexed::indexed(exvector * ivp) : inherited(ivp) +indexed::indexed(const symmetry & symm, std::auto_ptr vp) : inherited(vp), symtree(symm) { - debugmsg("indexed constructor from exvector *",LOGLEVEL_CONSTRUCT); - tinfo_key=TINFO_indexed; - GINAC_ASSERT(all_of_type_idx()); + tinfo_key = TINFO_indexed; } ////////// // archiving ////////// -/** Construct object from archive_node. */ -indexed::indexed(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst) -{ - debugmsg("indexed constructor from archive_node", LOGLEVEL_CONSTRUCT); -} - -/** Unarchive the object. */ -ex indexed::unarchive(const archive_node &n, const lst &sym_lst) +indexed::indexed(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst) { - return (new indexed(n, sym_lst))->setflag(status_flags::dynallocated); + if (!n.find_ex("symmetry", symtree, sym_lst)) { + // GiNaC versions <= 0.9.0 had an unsigned "symmetry" property + unsigned symm = 0; + n.find_unsigned("symmetry", symm); + switch (symm) { + case 1: + symtree = sy_symm(); + break; + case 2: + symtree = sy_anti(); + break; + default: + symtree = sy_none(); + break; + } + const_cast(ex_to(symtree)).validate(seq.size() - 1); + } } -/** Archive the object. */ void indexed::archive(archive_node &n) const { - inherited::archive(n); + inherited::archive(n); + n.add_ex("symmetry", symtree); } +DEFAULT_UNARCHIVE(indexed) + ////////// -// functions overriding virtual functions from bases classes +// functions overriding virtual functions from base classes ////////// -// public - -basic * indexed::duplicate() const +void indexed::printindices(const print_context & c, unsigned level) const { - debugmsg("indexed duplicate",LOGLEVEL_DUPLICATE); - return new indexed(*this); + if (seq.size() > 1) { + + exvector::const_iterator it=seq.begin() + 1, itend = seq.end(); + + if (is_a(c)) { + + // TeX output: group by variance + bool first = true; + bool covariant = true; + + while (it != itend) { + bool cur_covariant = (is_a(*it) ? ex_to(*it).is_covariant() : true); + if (first || cur_covariant != covariant) { // Variance changed + // The empty {} prevents indices from ending up on top of each other + if (!first) + c.s << "}{}"; + covariant = cur_covariant; + if (covariant) + c.s << "_{"; + else + c.s << "^{"; + } + it->print(c, level); + c.s << " "; + first = false; + it++; + } + c.s << "}"; + + } else { + + // Ordinary output + while (it != itend) { + it->print(c, level); + it++; + } + } + } } -void indexed::printraw(ostream & os) const +void indexed::print_indexed(const print_context & c, const char *openbrace, const char *closebrace, unsigned level) const { - debugmsg("indexed printraw",LOGLEVEL_PRINT); - os << "indexed(indices="; - printrawindices(os); - os << ",hash=" << hashvalue << ",flags=" << flags << ")"; + if (precedence() <= level) + c.s << openbrace << '('; + c.s << openbrace; + seq[0].print(c, precedence()); + c.s << closebrace; + printindices(c, level); + if (precedence() <= level) + c.s << ')' << closebrace; } -void indexed::printtree(ostream & os, unsigned indent) const +void indexed::do_print(const print_context & c, unsigned level) const { - debugmsg("indexed printtree",LOGLEVEL_PRINT); - os << string(indent,' ') << "indexed: " << seq.size() << " indices"; - os << ",hash=" << hashvalue << ",flags=" << flags << endl; - printtreeindices(os,indent); + print_indexed(c, "", "", level); } -void indexed::print(ostream & os, unsigned upper_precedence) const +void indexed::do_print_latex(const print_latex & c, unsigned level) const { - debugmsg("indexed print",LOGLEVEL_PRINT); - os << "UNNAMEDINDEX"; - printindices(os); + print_indexed(c, "{", "}", level); } -void indexed::printcsrc(ostream & os, unsigned type, - unsigned upper_precedence) const +void indexed::do_print_tree(const print_tree & c, unsigned level) const { - debugmsg("indexed print csrc",LOGLEVEL_PRINT); - print(os,upper_precedence); + c.s << std::string(level, ' ') << class_name() << " @" << this + << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec + << ", " << seq.size()-1 << " indices" + << ", symmetry=" << symtree << std::endl; + seq[0].print(c, level + c.delta_indent); + printindices(c, level + c.delta_indent); } bool indexed::info(unsigned inf) const { - if (inf==info_flags::indexed) return true; - if (inf==info_flags::has_indices) return seq.size()!=0; - return inherited::info(inf); + if (inf == info_flags::indexed) return true; + if (inf == info_flags::has_indices) return seq.size() > 1; + return inherited::info(inf); } -exvector indexed::get_indices(void) const +struct idx_is_not : public std::binary_function { + bool operator() (const ex & e, unsigned inf) const { + return !(ex_to(e).get_value().info(inf)); + } +}; + +bool indexed::all_index_values_are(unsigned inf) const { - return seq; + // No indices? Then no property can be fulfilled + if (seq.size() < 2) + return false; - /* - idxvector filtered_indices; - filtered_indices.reserve(indices.size()); - for (idxvector::const_iterator cit=indices.begin(); cit!=indices.end(); ++cit) { - if ((*cit).get_type()==t) { - filtered_indices.push_back(*cit); - } - } - return filtered_indices; - */ + // Check all indices + return find_if(seq.begin() + 1, seq.end(), bind2nd(idx_is_not(), inf)) == seq.end(); } -// protected - -int indexed::compare_same_type(basic const & other) const +int indexed::compare_same_type(const basic & other) const { - GINAC_ASSERT(is_of_type(other,indexed)); - return inherited::compare_same_type(other); + GINAC_ASSERT(is_a(other)); + return inherited::compare_same_type(other); } -bool indexed::is_equal_same_type(basic const & other) const +ex indexed::eval(int level) const { - GINAC_ASSERT(is_of_type(other,indexed)); - return inherited::is_equal_same_type(other); -} + // First evaluate children, then we will end up here again + if (level > 1) + return indexed(ex_to(symtree), evalchildren(level)); -unsigned indexed::return_type(void) const -{ - return return_types::noncommutative; + const ex &base = seq[0]; + + // If the base object is 0, the whole object is 0 + if (base.is_zero()) + return _ex0; + + // If the base object is a product, pull out the numeric factor + if (is_exactly_a(base) && is_exactly_a(base.op(base.nops() - 1))) { + exvector v(seq); + ex f = ex_to(base.op(base.nops() - 1)); + v[0] = seq[0] / f; + return f * thiscontainer(v); + } + + // Canonicalize indices according to the symmetry properties + if (seq.size() > 2) { + exvector v = seq; + GINAC_ASSERT(is_exactly_a(symtree)); + int sig = canonicalize(v.begin() + 1, ex_to(symtree)); + if (sig != INT_MAX) { + // Something has changed while sorting indices, more evaluations later + if (sig == 0) + return _ex0; + return ex(sig) * thiscontainer(v); + } + } + + // Let the class of the base object perform additional evaluations + return ex_to(base).eval_indexed(*this); } - -unsigned indexed::return_type_tinfo(void) const + +ex indexed::thiscontainer(const exvector & v) const { - return tinfo_key; + return indexed(ex_to(symtree), v); } -ex indexed::thisexprseq(exvector const & v) const +ex indexed::thiscontainer(std::auto_ptr vp) const { - return indexed(v); + return indexed(ex_to(symtree), vp); } -ex indexed::thisexprseq(exvector * vp) const +ex indexed::expand(unsigned options) const { - return indexed(vp); + GINAC_ASSERT(seq.size() > 0); + + if ((options & expand_options::expand_indexed) && is_exactly_a(seq[0])) { + + // expand_indexed expands (a+b).i -> a.i + b.i + const ex & base = seq[0]; + ex sum = _ex0; + for (size_t i=0; i 0); + exvector::const_iterator it = seq.begin() + 1, itend = seq.end(); + while (it != itend) { + if (!is_a(*it)) + throw(std::invalid_argument("indices of indexed object must be of type idx")); + it++; + } + + if (!symtree.is_zero()) { + if (!is_exactly_a(symtree)) + throw(std::invalid_argument("symmetry of indexed object must be of type symmetry")); + const_cast(ex_to(symtree)).validate(seq.size() - 1); + } +} + +/** Implementation of ex::diff() for an indexed object always returns 0. + * + * @see ex::diff */ +ex indexed::derivative(const symbol & s) const +{ + return _ex0; +} + +////////// +// global functions +////////// + +struct idx_is_equal_ignore_dim : public std::binary_function { + bool operator() (const ex &lh, const ex &rh) const + { + if (lh.is_equal(rh)) + return true; + else + try { + // Replacing the dimension might cause an error (e.g. with + // index classes that only work in a fixed number of dimensions) + return lh.is_equal(ex_to(rh).replace_dim(ex_to(lh).get_dim())); + } catch (...) { + return false; + } + } +}; -void indexed::printrawindices(ostream & os) const +/** Check whether two sorted index vectors are consistent (i.e. equal). */ +static bool indices_consistent(const exvector & v1, const exvector & v2) { - if (seq.size()!=0) { - for (exvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) { - (*cit).printraw(os); - os << ","; - } - } + // Number of indices must be the same + if (v1.size() != v2.size()) + return false; + + return equal(v1.begin(), v1.end(), v2.begin(), idx_is_equal_ignore_dim()); } -void indexed::printtreeindices(ostream & os, unsigned indent) const +exvector indexed::get_indices() const { - if (seq.size()!=0) { - for (exvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) { - os << string(indent+delta_indent,' '); - (*cit).printraw(os); - os << endl; - } - } + GINAC_ASSERT(seq.size() >= 1); + return exvector(seq.begin() + 1, seq.end()); } -void indexed::printindices(ostream & os) const +exvector indexed::get_dummy_indices() const { - if (seq.size()!=0) { - if (seq.size()>1) { - os << "{"; - } - exvector::const_iterator last=seq.end()-1; - exvector::const_iterator cit=seq.begin(); - for (; cit!=last; ++cit) { - (*cit).print(os); - os << ","; - } - (*cit).print(os); - if (seq.size()>1) { - os << "}"; - } - } + exvector free_indices, dummy_indices; + find_free_and_dummy(seq.begin() + 1, seq.end(), free_indices, dummy_indices); + return dummy_indices; } -bool indexed::all_of_type_idx(void) const +exvector indexed::get_dummy_indices(const indexed & other) const { - // used only inside of ASSERTs - for (exvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) { - if (!is_ex_of_type(*cit,idx)) return false; - } - return true; + exvector indices = get_free_indices(); + exvector other_indices = other.get_free_indices(); + indices.insert(indices.end(), other_indices.begin(), other_indices.end()); + exvector dummy_indices; + find_dummy_indices(indices, dummy_indices); + return dummy_indices; } -////////// -// static member variables -////////// +bool indexed::has_dummy_index_for(const ex & i) const +{ + exvector::const_iterator it = seq.begin() + 1, itend = seq.end(); + while (it != itend) { + if (is_dummy_pair(*it, i)) + return true; + it++; + } + return false; +} -// none +exvector indexed::get_free_indices() const +{ + exvector free_indices, dummy_indices; + find_free_and_dummy(seq.begin() + 1, seq.end(), free_indices, dummy_indices); + return free_indices; +} + +exvector add::get_free_indices() const +{ + exvector free_indices; + for (size_t i=0; i 0) { + if (find_if(global_dummy_indices.begin(), global_dummy_indices.end(), bind2nd(op0_is_equal(), *it)) == global_dummy_indices.end()) { + global_dummy_indices.push_back(*it); + global_size++; + remaining--; + } + it++; + } + + // If this is the first set of local indices, do nothing + if (old_global_size == 0) + return e; + } + GINAC_ASSERT(local_size <= global_size); + + // Construct vectors of index symbols + exvector local_syms, global_syms; + local_syms.reserve(local_size); + global_syms.reserve(local_size); + for (size_t i=0; i(local_uniq), ex_is_less()); + set_difference(global_syms.begin(), global_syms.end(), local_syms.begin(), local_syms.end(), std::back_insert_iterator(global_uniq), ex_is_less()); + + // Replace remaining non-common local index symbols by global ones + if (local_uniq.empty()) + return e; + else { + while (global_uniq.size() > local_uniq.size()) + global_uniq.pop_back(); + return e.subs(lst(local_uniq.begin(), local_uniq.end()), lst(global_uniq.begin(), global_uniq.end()), subs_options::no_pattern); + } +} + +/** Given a set of indices, extract those of class varidx. */ +static void find_variant_indices(const exvector & v, exvector & variant_indices) +{ + exvector::const_iterator it1, itend; + for (it1 = v.begin(), itend = v.end(); it1 != itend; ++it1) { + if (is_exactly_a(*it1)) + variant_indices.push_back(*it1); + } +} + +/** Raise/lower dummy indices in a single indexed objects to canonicalize their + * variance. + * + * @param e Object to work on + * @param variant_dummy_indices The set of indices that might need repositioning (will be changed by this function) + * @param moved_indices The set of indices that have been repositioned (will be changed by this function) + * @return true if 'e' was changed */ +bool reposition_dummy_indices(ex & e, exvector & variant_dummy_indices, exvector & moved_indices) +{ + bool something_changed = false; + + // If a dummy index is encountered for the first time in the + // product, pull it up, otherwise, pull it down + exvector::const_iterator it2, it2start, it2end; + for (it2start = ex_to(e).seq.begin(), it2end = ex_to(e).seq.end(), it2 = it2start + 1; it2 != it2end; ++it2) { + if (!is_exactly_a(*it2)) + continue; + + exvector::iterator vit, vitend; + for (vit = variant_dummy_indices.begin(), vitend = variant_dummy_indices.end(); vit != vitend; ++vit) { + if (it2->op(0).is_equal(vit->op(0))) { + if (ex_to(*it2).is_covariant()) { + e = e.subs(lst( + *it2 == ex_to(*it2).toggle_variance(), + ex_to(*it2).toggle_variance() == *it2 + ), subs_options::no_pattern); + something_changed = true; + it2 = ex_to(e).seq.begin() + (it2 - it2start); + it2start = ex_to(e).seq.begin(); + it2end = ex_to(e).seq.end(); + } + moved_indices.push_back(*vit); + variant_dummy_indices.erase(vit); + goto next_index; + } + } + + for (vit = moved_indices.begin(), vitend = moved_indices.end(); vit != vitend; ++vit) { + if (it2->op(0).is_equal(vit->op(0))) { + if (ex_to(*it2).is_contravariant()) { + e = e.subs(*it2 == ex_to(*it2).toggle_variance(), subs_options::no_pattern); + something_changed = true; + it2 = ex_to(e).seq.begin() + (it2 - it2start); + it2start = ex_to(e).seq.begin(); + it2end = ex_to(e).seq.end(); + } + goto next_index; + } + } + +next_index: ; + } + + return something_changed; +} + +/* Ordering that only compares the base expressions of indexed objects. */ +struct ex_base_is_less : public std::binary_function { + bool operator() (const ex &lh, const ex &rh) const + { + return (is_a(lh) ? lh.op(0) : lh).compare(is_a(rh) ? rh.op(0) : rh) < 0; + } +}; + +/** Simplify product of indexed expressions (commutative, noncommutative and + * simple squares), return list of free indices. */ +ex simplify_indexed_product(const ex & e, exvector & free_indices, exvector & dummy_indices, const scalar_products & sp) +{ + // Remember whether the product was commutative or noncommutative + // (because we chop it into factors and need to reassemble later) + bool non_commutative = is_exactly_a(e); + + // Collect factors in an exvector, store squares twice + exvector v; + v.reserve(e.nops() * 2); + + if (is_exactly_a(e)) { + // We only get called for simple squares, split a^2 -> a*a + GINAC_ASSERT(e.op(1).is_equal(_ex2)); + v.push_back(e.op(0)); + v.push_back(e.op(0)); + } else { + for (size_t i=0; i(f) && f.op(1).is_equal(_ex2)) { + v.push_back(f.op(0)); + v.push_back(f.op(0)); + } else if (is_exactly_a(f)) { + // Noncommutative factor found, split it as well + non_commutative = true; // everything becomes noncommutative, ncmul will sort out the commutative factors later + for (size_t j=0; j 1); + exvector::iterator it1, itend = v.end(), next_to_last = itend - 1; + for (it1 = v.begin(); it1 != next_to_last; it1++) { + +try_again: + if (!is_a(*it1)) + continue; + + bool first_noncommutative = (it1->return_type() != return_types::commutative); + + // Indexed factor found, get free indices and look for contraction + // candidates + exvector free1, dummy1; + find_free_and_dummy(ex_to(*it1).seq.begin() + 1, ex_to(*it1).seq.end(), free1, dummy1); + + exvector::iterator it2; + for (it2 = it1 + 1; it2 != itend; it2++) { + + if (!is_a(*it2)) + continue; + + bool second_noncommutative = (it2->return_type() != return_types::commutative); + + // Find free indices of second factor and merge them with free + // indices of first factor + exvector un; + find_free_and_dummy(ex_to(*it2).seq.begin() + 1, ex_to(*it2).seq.end(), un, dummy1); + un.insert(un.end(), free1.begin(), free1.end()); + + // Check whether the two factors share dummy indices + exvector free, dummy; + find_free_and_dummy(un, free, dummy); + size_t num_dummies = dummy.size(); + if (num_dummies == 0) + continue; + + // At least one dummy index, is it a defined scalar product? + bool contracted = false; + if (free.empty()) { + + // Find minimal dimension of all indices of both factors + exvector::const_iterator dit = ex_to(*it1).seq.begin() + 1, ditend = ex_to(*it1).seq.end(); + ex dim = ex_to(*dit).get_dim(); + ++dit; + for (; dit != ditend; ++dit) { + dim = minimal_dim(dim, ex_to(*dit).get_dim()); + } + dit = ex_to(*it2).seq.begin() + 1; + ditend = ex_to(*it2).seq.end(); + for (; dit != ditend; ++dit) { + dim = minimal_dim(dim, ex_to(*dit).get_dim()); + } + + // User-defined scalar product? + if (sp.is_defined(*it1, *it2, dim)) { + + // Yes, substitute it + *it1 = sp.evaluate(*it1, *it2, dim); + *it2 = _ex1; + goto contraction_done; + } + } + + // Try to contract the first one with the second one + contracted = ex_to(it1->op(0)).contract_with(it1, it2, v); + if (!contracted) { + + // That didn't work; maybe the second object knows how to + // contract itself with the first one + contracted = ex_to(it2->op(0)).contract_with(it2, it1, v); + } + if (contracted) { +contraction_done: + if (first_noncommutative || second_noncommutative + || is_exactly_a(*it1) || is_exactly_a(*it2) + || is_exactly_a(*it1) || is_exactly_a(*it2) + || is_exactly_a(*it1) || is_exactly_a(*it2)) { + + // One of the factors became a sum or product: + // re-expand expression and run again + // Non-commutative products are always re-expanded to give + // eval_ncmul() the chance to re-order and canonicalize + // the product + ex r = (non_commutative ? ex(ncmul(v, true)) : ex(mul(v))); + return simplify_indexed(r, free_indices, dummy_indices, sp); + } + + // Both objects may have new indices now or they might + // even not be indexed objects any more, so we have to + // start over + something_changed = true; + goto try_again; + } + } + } + + // Find free indices (concatenate them all and call find_free_and_dummy()) + // and all dummy indices that appear + exvector un, individual_dummy_indices; + for (it1 = v.begin(), itend = v.end(); it1 != itend; ++it1) { + exvector free_indices_of_factor; + if (is_a(*it1)) { + exvector dummy_indices_of_factor; + find_free_and_dummy(ex_to(*it1).seq.begin() + 1, ex_to(*it1).seq.end(), free_indices_of_factor, dummy_indices_of_factor); + individual_dummy_indices.insert(individual_dummy_indices.end(), dummy_indices_of_factor.begin(), dummy_indices_of_factor.end()); + } else + free_indices_of_factor = it1->get_free_indices(); + un.insert(un.end(), free_indices_of_factor.begin(), free_indices_of_factor.end()); + } + exvector local_dummy_indices; + find_free_and_dummy(un, free_indices, local_dummy_indices); + local_dummy_indices.insert(local_dummy_indices.end(), individual_dummy_indices.begin(), individual_dummy_indices.end()); + + // Filter out the dummy indices with variance + exvector variant_dummy_indices; + find_variant_indices(local_dummy_indices, variant_dummy_indices); + + // Any indices with variance present at all? + if (!variant_dummy_indices.empty()) { + + // Yes, bring the product into a canonical order that only depends on + // the base expressions of indexed objects + if (!non_commutative) + std::sort(v.begin(), v.end(), ex_base_is_less()); + + exvector moved_indices; + + // Iterate over all indexed objects in the product + for (it1 = v.begin(), itend = v.end(); it1 != itend; ++it1) { + if (!is_a(*it1)) + continue; + + if (reposition_dummy_indices(*it1, variant_dummy_indices, moved_indices)) + something_changed = true; + } + } + + ex r; + if (something_changed) + r = non_commutative ? ex(ncmul(v, true)) : ex(mul(v)); + else + r = e; + + // The result should be symmetric with respect to exchange of dummy + // indices, so if the symmetrization vanishes, the whole expression is + // zero. This detects things like eps.i.j.k * p.j * p.k = 0. + if (local_dummy_indices.size() >= 2) { + exvector dummy_syms; + dummy_syms.reserve(local_dummy_indices.size()); + for (exvector::const_iterator it = local_dummy_indices.begin(); it != local_dummy_indices.end(); ++it) + dummy_syms.push_back(it->op(0)); + if (symmetrize(r, dummy_syms).is_zero()) { + free_indices.clear(); + return _ex0; + } + } + + // Dummy index renaming + r = rename_dummy_indices(r, dummy_indices, local_dummy_indices); + + // Product of indexed object with a scalar? + if (is_exactly_a(r) && r.nops() == 2 + && is_exactly_a(r.op(1)) && is_a(r.op(0))) + return ex_to(r.op(0).op(0)).scalar_mul_indexed(r.op(0), ex_to(r.op(1))); + else + return r; +} + +/** This structure stores the original and symmetrized versions of terms + * obtained during the simplification of sums. */ +class terminfo { +public: + terminfo(const ex & orig_, const ex & symm_) : orig(orig_), symm(symm_) {} + + ex orig; /**< original term */ + ex symm; /**< symmtrized term */ +}; + +class terminfo_is_less { +public: + bool operator() (const terminfo & ti1, const terminfo & ti2) const + { + return (ti1.symm.compare(ti2.symm) < 0); + } +}; + +/** This structure stores the individual symmetrized terms obtained during + * the simplification of sums. */ +class symminfo { +public: + symminfo() : num(0) {} + + symminfo(const ex & symmterm_, const ex & orig_, size_t num_) : orig(orig_), num(num_) + { + if (is_exactly_a(symmterm_) && is_exactly_a(symmterm_.op(symmterm_.nops()-1))) { + coeff = symmterm_.op(symmterm_.nops()-1); + symmterm = symmterm_ / coeff; + } else { + coeff = 1; + symmterm = symmterm_; + } + } + + ex symmterm; /**< symmetrized term */ + ex coeff; /**< coefficient of symmetrized term */ + ex orig; /**< original term */ + size_t num; /**< how many symmetrized terms resulted from the original term */ +}; + +class symminfo_is_less_by_symmterm { +public: + bool operator() (const symminfo & si1, const symminfo & si2) const + { + return (si1.symmterm.compare(si2.symmterm) < 0); + } +}; + +class symminfo_is_less_by_orig { +public: + bool operator() (const symminfo & si1, const symminfo & si2) const + { + return (si1.orig.compare(si2.orig) < 0); + } +}; + +/** Simplify indexed expression, return list of free indices. */ +ex simplify_indexed(const ex & e, exvector & free_indices, exvector & dummy_indices, const scalar_products & sp) +{ + // Expand the expression + ex e_expanded = e.expand(); + + // Simplification of single indexed object: just find the free indices + // and perform dummy index renaming/repositioning + if (is_a(e_expanded)) { + + // Find the dummy indices + const indexed &i = ex_to(e_expanded); + exvector local_dummy_indices; + find_free_and_dummy(i.seq.begin() + 1, i.seq.end(), free_indices, local_dummy_indices); + + // Filter out the dummy indices with variance + exvector variant_dummy_indices; + find_variant_indices(local_dummy_indices, variant_dummy_indices); + + // Any indices with variance present at all? + if (!variant_dummy_indices.empty()) { + + // Yes, reposition them + exvector moved_indices; + reposition_dummy_indices(e_expanded, variant_dummy_indices, moved_indices); + } + + // Rename the dummy indices + return rename_dummy_indices(e_expanded, dummy_indices, local_dummy_indices); + } + + // Simplification of sum = sum of simplifications, check consistency of + // free indices in each term + if (is_exactly_a(e_expanded)) { + bool first = true; + ex sum; + free_indices.clear(); + + for (size_t i=0; i(sum) && is_a(term)) + sum = ex_to(sum.op(0)).add_indexed(sum, term); + else + sum += term; + } + } + } + + // If the sum turns out to be zero, we are finished + if (sum.is_zero()) { + free_indices.clear(); + return sum; + } + + // More than one term and more than one dummy index? + size_t num_terms_orig = (is_exactly_a(sum) ? sum.nops() : 1); + if (num_terms_orig < 2 || dummy_indices.size() < 2) + return sum; + + // Yes, construct vector of all dummy index symbols + exvector dummy_syms; + dummy_syms.reserve(dummy_indices.size()); + for (exvector::const_iterator it = dummy_indices.begin(); it != dummy_indices.end(); ++it) + dummy_syms.push_back(it->op(0)); + + // Chop the sum into terms and symmetrize each one over the dummy + // indices + std::vector terms; + for (size_t i=0; i terms_pass2; + for (std::vector::const_iterator i=terms.begin(); i!=terms.end(); ) { + size_t num = 1; + std::vector::const_iterator j = i + 1; + while (j != terms.end() && j->symm == i->symm) { + num++; + j++; + } + terms_pass2.push_back(terminfo(i->orig * num, i->symm * num)); + i = j; + } + + // If there is only one term left, we are finished + if (terms_pass2.size() == 1) + return terms_pass2[0].orig; + + // Chop the symmetrized terms into subterms + std::vector sy; + for (std::vector::const_iterator i=terms_pass2.begin(); i!=terms_pass2.end(); ++i) { + if (is_exactly_a(i->symm)) { + size_t num = i->symm.nops(); + for (size_t j=0; jsymm.op(j), i->orig, num)); + } else + sy.push_back(symminfo(i->symm, i->orig, 1)); + } + + // Sort by symmetrized subterms + std::sort(sy.begin(), sy.end(), symminfo_is_less_by_symmterm()); + + // Combine equal symmetrized subterms + std::vector sy_pass2; + exvector result; + for (std::vector::const_iterator i=sy.begin(); i!=sy.end(); ) { + + // Combine equal terms + std::vector::const_iterator j = i + 1; + if (j != sy.end() && j->symmterm == i->symmterm) { + + // More than one term, collect the coefficients + ex coeff = i->coeff; + while (j != sy.end() && j->symmterm == i->symmterm) { + coeff += j->coeff; + j++; + } + + // Add combined term to result + if (!coeff.is_zero()) + result.push_back(coeff * i->symmterm); + + } else { + + // Single term, store for second pass + sy_pass2.push_back(*i); + } + + i = j; + } + + // Were there any remaining terms that didn't get combined? + if (sy_pass2.size() > 0) { + + // Yes, sort by their original terms + std::sort(sy_pass2.begin(), sy_pass2.end(), symminfo_is_less_by_orig()); + + for (std::vector::const_iterator i=sy_pass2.begin(); i!=sy_pass2.end(); ) { + + // How many symmetrized terms of this original term are left? + size_t num = 1; + std::vector::const_iterator j = i + 1; + while (j != sy_pass2.end() && j->orig == i->orig) { + num++; + j++; + } + + if (num == i->num) { + + // All terms left, then add the original term to the result + result.push_back(i->orig); + + } else { + + // Some terms were combined with others, add up the remaining symmetrized terms + std::vector::const_iterator k; + for (k=i; k!=j; k++) + result.push_back(k->coeff * k->symmterm); + } + + i = j; + } + } + + // Add all resulting terms + ex sum_symm = (new add(result))->setflag(status_flags::dynallocated); + if (sum_symm.is_zero()) + free_indices.clear(); + return sum_symm; + } + + // Simplification of products + if (is_exactly_a(e_expanded) + || is_exactly_a(e_expanded) + || (is_exactly_a(e_expanded) && is_a(e_expanded.op(0)) && e_expanded.op(1).is_equal(_ex2))) + return simplify_indexed_product(e_expanded, free_indices, dummy_indices, sp); + + // Cannot do anything + free_indices.clear(); + return e_expanded; +} + +/** Simplify/canonicalize expression containing indexed objects. This + * performs contraction of dummy indices where possible and checks whether + * the free indices in sums are consistent. + * + * @return simplified expression */ +ex ex::simplify_indexed(unsigned options) const +{ + exvector free_indices, dummy_indices; + scalar_products sp; + return GiNaC::simplify_indexed(*this, free_indices, dummy_indices, sp); +} + +/** Simplify/canonicalize expression containing indexed objects. This + * performs contraction of dummy indices where possible, checks whether + * the free indices in sums are consistent, and automatically replaces + * scalar products by known values if desired. + * + * @param sp Scalar products to be replaced automatically + * @return simplified expression */ +ex ex::simplify_indexed(const scalar_products & sp, unsigned options) const +{ + exvector free_indices, dummy_indices; + return GiNaC::simplify_indexed(*this, free_indices, dummy_indices, sp); +} + +/** Symmetrize expression over its free indices. */ +ex ex::symmetrize() const +{ + return GiNaC::symmetrize(*this, get_free_indices()); +} + +/** Antisymmetrize expression over its free indices. */ +ex ex::antisymmetrize() const +{ + return GiNaC::antisymmetrize(*this, get_free_indices()); +} + +/** Symmetrize expression by cyclic permutation over its free indices. */ +ex ex::symmetrize_cyclic() const +{ + return GiNaC::symmetrize_cyclic(*this, get_free_indices()); +} ////////// -// global constants +// helper classes ////////// -const indexed some_indexed; -type_info const & typeid_indexed=typeid(some_indexed); +spmapkey::spmapkey(const ex & v1_, const ex & v2_, const ex & dim_) : dim(dim_) +{ + // If indexed, extract base objects + ex s1 = is_a(v1_) ? v1_.op(0) : v1_; + ex s2 = is_a(v2_) ? v2_.op(0) : v2_; + + // Enforce canonical order in pair + if (s1.compare(s2) > 0) { + v1 = s2; + v2 = s1; + } else { + v1 = s1; + v2 = s2; + } +} + +bool spmapkey::operator==(const spmapkey &other) const +{ + if (!v1.is_equal(other.v1)) + return false; + if (!v2.is_equal(other.v2)) + return false; + if (is_a(dim) || is_a(other.dim)) + return true; + else + return dim.is_equal(other.dim); +} + +bool spmapkey::operator<(const spmapkey &other) const +{ + int cmp = v1.compare(other.v1); + if (cmp) + return cmp < 0; + cmp = v2.compare(other.v2); + if (cmp) + return cmp < 0; + + // Objects are equal, now check dimensions + if (is_a(dim) || is_a(other.dim)) + return false; + else + return dim.compare(other.dim) < 0; +} + +void spmapkey::debugprint() const +{ + std::cerr << "(" << v1 << "," << v2 << "," << dim << ")"; +} + +void scalar_products::add(const ex & v1, const ex & v2, const ex & sp) +{ + spm[spmapkey(v1, v2)] = sp; +} + +void scalar_products::add(const ex & v1, const ex & v2, const ex & dim, const ex & sp) +{ + spm[spmapkey(v1, v2, dim)] = sp; +} + +void scalar_products::add_vectors(const lst & l, const ex & dim) +{ + // Add all possible pairs of products + for (lst::const_iterator it1 = l.begin(); it1 != l.end(); ++it1) + for (lst::const_iterator it2 = l.begin(); it2 != l.end(); ++it2) + add(*it1, *it2, *it1 * *it2); +} + +void scalar_products::clear() +{ + spm.clear(); +} + +/** Check whether scalar product pair is defined. */ +bool scalar_products::is_defined(const ex & v1, const ex & v2, const ex & dim) const +{ + return spm.find(spmapkey(v1, v2, dim)) != spm.end(); +} + +/** Return value of defined scalar product pair. */ +ex scalar_products::evaluate(const ex & v1, const ex & v2, const ex & dim) const +{ + return spm.find(spmapkey(v1, v2, dim))->second; +} + +void scalar_products::debugprint() const +{ + std::cerr << "map size=" << spm.size() << std::endl; + spmap::const_iterator i = spm.begin(), end = spm.end(); + while (i != end) { + const spmapkey & k = i->first; + std::cerr << "item key="; + k.debugprint(); + std::cerr << ", value=" << i->second << std::endl; + ++i; + } +} -#ifndef NO_GINAC_NAMESPACE } // namespace GiNaC -#endif // ndef NO_GINAC_NAMESPACE