]> www.ginac.de Git - ginac.git/blobdiff - ginac/expairseq.cpp
Improved dummy index renaming.
[ginac.git] / ginac / expairseq.cpp
index 9d72a7873c45ee23a4a4ceb0236a62571dfafe09..8e9594b6e312b640775ad59fd8d0cb8e66b8592a 100644 (file)
@@ -119,20 +119,20 @@ expairseq::expairseq(const exvector &v) : inherited(&expairseq::tinfo_static)
        GINAC_ASSERT(is_canonical());
 }
 
-expairseq::expairseq(const epvector &v, const ex &oc)
+expairseq::expairseq(const epvector &v, const ex &oc, bool do_index_renaming)
   : inherited(&expairseq::tinfo_static), overall_coeff(oc)
 {
        GINAC_ASSERT(is_a<numeric>(oc));
-       construct_from_epvector(v);
+       construct_from_epvector(v, do_index_renaming);
        GINAC_ASSERT(is_canonical());
 }
 
-expairseq::expairseq(std::auto_ptr<epvector> vp, const ex &oc)
+expairseq::expairseq(std::auto_ptr<epvector> vp, const ex &oc, bool do_index_renaming)
   : inherited(&expairseq::tinfo_static), overall_coeff(oc)
 {
        GINAC_ASSERT(vp.get()!=0);
        GINAC_ASSERT(is_a<numeric>(oc));
-       construct_from_epvector(*vp);
+       construct_from_epvector(*vp, do_index_renaming);
        GINAC_ASSERT(is_canonical());
 }
 
@@ -294,9 +294,9 @@ ex expairseq::map(map_function &f) const
        }
 
        if (overall_coeff.is_equal(default_overall_coeff()))
-               return thisexpairseq(v, default_overall_coeff());
+               return thisexpairseq(v, default_overall_coeff(), true);
        else
-               return thisexpairseq(v, f(overall_coeff));
+               return thisexpairseq(v, f(overall_coeff), true);
 }
 
 /** Perform coefficient-wise automatic term rewriting rules in this class. */
@@ -447,7 +447,7 @@ ex expairseq::subs(const exmap & m, unsigned options) const
 {
        std::auto_ptr<epvector> vp = subschildren(m, options);
        if (vp.get())
-               return ex_to<basic>(thisexpairseq(vp, overall_coeff));
+               return ex_to<basic>(thisexpairseq(vp, overall_coeff, true));
        else if ((options & subs_options::algebraic) && is_exactly_a<mul>(*this))
                return static_cast<const mul *>(this)->algebraic_subs_mul(m, options);
        else
@@ -642,14 +642,14 @@ ex expairseq::expand(unsigned options) const
  *  ctor because the name (add, mul,...) is unknown on the expaiseq level.  In
  *  order for this trick to work a derived class must of course override this
  *  definition. */
-ex expairseq::thisexpairseq(const epvector &v, const ex &oc) const
+ex expairseq::thisexpairseq(const epvector &v, const ex &oc, bool do_index_renaming) const
 {
-       return expairseq(v, oc);
+       return expairseq(v, oc, do_index_renaming);
 }
 
-ex expairseq::thisexpairseq(std::auto_ptr<epvector> vp, const ex &oc) const
+ex expairseq::thisexpairseq(std::auto_ptr<epvector> vp, const ex &oc, bool do_index_renaming) const
 {
-       return expairseq(vp, oc);
+       return expairseq(vp, oc, do_index_renaming);
 }
 
 void expairseq::printpair(const print_context & c, const expair & p, unsigned upper_precedence) const
@@ -781,7 +781,7 @@ void expairseq::construct_from_2_ex(const ex &lh, const ex &rh)
                        } else {
 #endif // EXPAIRSEQ_USE_HASHTAB
                                if(is_a<mul>(lh))
-                               {       
+                               {
                                        ex newrh=rename_dummy_indices_uniquely(lh, rh);
                                        construct_from_2_expairseq(ex_to<expairseq>(lh),
                                                                   ex_to<expairseq>(newrh));
@@ -999,14 +999,14 @@ void expairseq::construct_from_exvector(const exvector &v)
 #endif // EXPAIRSEQ_USE_HASHTAB
 }
 
-void expairseq::construct_from_epvector(const epvector &v)
+void expairseq::construct_from_epvector(const epvector &v, bool do_index_renaming)
 {
        // simplifications: +(a,+(b,c),d) -> +(a,b,c,d) (associativity)
        //                  +(d,b,c,a) -> +(a,b,c,d) (canonicalization)
        //                  +(...,x,*(x,c1),*(x,c2)) -> +(...,*(x,1+c1+c2)) (c1, c2 numeric())
        //                  (same for (+,*) -> (*,^)
 
-       make_flat(v);
+       make_flat(v, do_index_renaming);
 #if EXPAIRSEQ_USE_HASHTAB
        combine_same_terms();
 #else
@@ -1015,6 +1015,61 @@ void expairseq::construct_from_epvector(const epvector &v)
 #endif // EXPAIRSEQ_USE_HASHTAB
 }
 
+// Class to handle the renaming of dummy indices. It holds a vector of
+// indices that are being used in the expression so-far. If the same
+// index occurs again as a dummy index in a factor, it is to be renamed.
+// Unless dummy index renaming was swichted of, of course ;-) .
+class make_flat_inserter
+{
+       public:
+               make_flat_inserter(const epvector &epv, bool b): do_renaming(b)
+               {
+                       if (!do_renaming)
+                               return;
+                       for (epvector::const_iterator i=epv.begin(); i!=epv.end(); ++i)
+                               if(are_ex_trivially_equal(i->coeff, _ex1))
+                                       combine_indices(i->rest.get_free_indices());
+               }
+               make_flat_inserter(const exvector &v, bool b): do_renaming(b)
+               {
+                       if (!do_renaming)
+                               return;
+                       for (exvector::const_iterator i=v.begin(); i!=v.end(); ++i)
+                               combine_indices(i->get_free_indices());
+               }
+               ex handle_factor(const ex &x, const ex &coeff)
+               {
+                       if (!do_renaming)
+                               return x;
+                       exvector dummies_of_factor;
+                       if (coeff == _ex1)
+                               dummies_of_factor = get_all_dummy_indices_safely(x);
+                       else if (coeff == _ex2)
+                               dummies_of_factor = x.get_free_indices();
+                       else
+                               return x;
+                       if (dummies_of_factor.size() == 0)
+                               return x;
+                       sort(dummies_of_factor.begin(), dummies_of_factor.end(), ex_is_less());
+                       ex new_factor = rename_dummy_indices_uniquely(used_indices,
+                               dummies_of_factor, x);
+                       combine_indices(dummies_of_factor);
+                       return new_factor;
+               }
+       private:
+               void combine_indices(const exvector &dummies_of_factor)
+               {
+                       exvector new_dummy_indices;
+                       set_union(used_indices.begin(), used_indices.end(),
+                               dummies_of_factor.begin(), dummies_of_factor.end(),
+                               std::back_insert_iterator<exvector>(new_dummy_indices), ex_is_less());
+                       used_indices.swap(new_dummy_indices);
+               }
+               bool do_renaming;
+               exvector used_indices;
+};
+
+
 /** Combine this expairseq with argument exvector.
  *  It cares for associativity as well as for special handling of numerics. */
 void expairseq::make_flat(const exvector &v)
@@ -1039,35 +1094,25 @@ void expairseq::make_flat(const exvector &v)
        seq.reserve(v.size()+noperands-nexpairseqs);
        
        // copy elements and split off numerical part
-       exvector dummy_indices;
+       make_flat_inserter mf(v, this->tinfo()==&mul::tinfo_static);
        cit = v.begin();
        while (cit!=v.end()) {
                if (ex_to<basic>(*cit).tinfo()==this->tinfo()) {
-                       const expairseq *subseqref;
-                       ex newfactor;
-                       if(is_a<mul>(*cit))
-                       {
-                               exvector dummies_of_factor = get_all_dummy_indices(*cit);
-                               sort(dummies_of_factor.begin(), dummies_of_factor.end(), ex_is_less());
-                               newfactor = rename_dummy_indices_uniquely(dummy_indices, dummies_of_factor, *cit);
-                               subseqref = &(ex_to<expairseq>(newfactor));
-                               exvector new_dummy_indices;
-                               set_union(dummy_indices.begin(), dummy_indices.end(), dummies_of_factor.begin(), dummies_of_factor.end(), std::back_insert_iterator<exvector>(new_dummy_indices), ex_is_less());
-                               dummy_indices.swap(new_dummy_indices);
-                       }
-                       else
-                               subseqref = &ex_to<expairseq>(*cit);
-                       combine_overall_coeff(subseqref->overall_coeff);
-                       epvector::const_iterator cit_s = subseqref->seq.begin();
-                       while (cit_s!=subseqref->seq.end()) {
+                       ex newfactor = mf.handle_factor(*cit, _ex1);
+                       const expairseq &subseqref = ex_to<expairseq>(newfactor);
+                       combine_overall_coeff(subseqref.overall_coeff);
+                       epvector::const_iterator cit_s = subseqref.seq.begin();
+                       while (cit_s!=subseqref.seq.end()) {
                                seq.push_back(*cit_s);
                                ++cit_s;
                        }
                } else {
                        if (is_exactly_a<numeric>(*cit))
                                combine_overall_coeff(*cit);
-                       else
-                               seq.push_back(split_ex_to_pair(*cit));
+                       else {
+                               ex newfactor = mf.handle_factor(*cit, _ex1);
+                               seq.push_back(split_ex_to_pair(newfactor));
+                       }
                }
                ++cit;
        }
@@ -1075,7 +1120,7 @@ void expairseq::make_flat(const exvector &v)
 
 /** Combine this expairseq with argument epvector.
  *  It cares for associativity as well as for special handling of numerics. */
-void expairseq::make_flat(const epvector &v)
+void expairseq::make_flat(const epvector &v, bool do_index_renaming)
 {
        epvector::const_iterator cit;
        
@@ -1095,13 +1140,15 @@ void expairseq::make_flat(const epvector &v)
        
        // reserve seq and coeffseq which will hold all operands
        seq.reserve(v.size()+noperands-nexpairseqs);
+       make_flat_inserter mf(v, do_index_renaming);
        
        // copy elements and split off numerical part
        cit = v.begin();
        while (cit!=v.end()) {
                if (ex_to<basic>(cit->rest).tinfo()==this->tinfo() &&
                    this->can_make_flat(*cit)) {
-                       const expairseq &subseqref = ex_to<expairseq>(cit->rest);
+                       ex newrest = mf.handle_factor(cit->rest, cit->coeff);
+                       const expairseq &subseqref = ex_to<expairseq>(newrest);
                        combine_overall_coeff(ex_to<numeric>(subseqref.overall_coeff),
                                                            ex_to<numeric>(cit->coeff));
                        epvector::const_iterator cit_s = subseqref.seq.begin();
@@ -1114,9 +1161,15 @@ void expairseq::make_flat(const epvector &v)
                        }
                } else {
                        if (cit->is_canonical_numeric())
-                               combine_overall_coeff(cit->rest);
-                       else
-                               seq.push_back(*cit);
+                               combine_overall_coeff(mf.handle_factor(cit->rest, _ex1));
+                       else {
+                               ex rest = cit->rest;
+                               ex newrest = mf.handle_factor(rest, cit->coeff);
+                               if (are_ex_trivially_equal(newrest, rest))
+                                       seq.push_back(*cit);
+                               else
+                                       seq.push_back(expair(newrest, cit->coeff));
+                       }
                }
                ++cit;
        }
@@ -1624,68 +1677,6 @@ std::auto_ptr<epvector> expairseq::evalchildren(int level) const
        return std::auto_ptr<epvector>(0); // signalling nothing has changed
 }
 
-class safe_inserter
-{
-       public:
-               safe_inserter(const ex&, const bool disable_renaming=false);
-               std::auto_ptr<epvector> getseq(){return epv;}
-               void insert_old_pair(const expair &p)
-               {
-                       epv->push_back(p);
-               }
-               void insert_new_pair(const expair &p, const ex &orig_ex);
-       private:
-               std::auto_ptr<epvector> epv;
-               bool dodummies;
-               exvector dummy_indices;
-               void update_dummy_indices(const exvector&);
-};
-
-safe_inserter::safe_inserter(const ex&e, const bool disable_renaming)
-               :epv(new epvector)
-{
-       epv->reserve(e.nops());
-       dodummies=is_a<mul>(e);
-       if(disable_renaming)
-               dodummies=false;
-       if(dodummies) {
-               dummy_indices = get_all_dummy_indices_safely(e);
-               sort(dummy_indices.begin(), dummy_indices.end(), ex_is_less());
-       }
-}
-
-void safe_inserter::update_dummy_indices(const exvector &v)
-{
-       exvector new_dummy_indices;
-       set_union(dummy_indices.begin(), dummy_indices.end(), v.begin(), v.end(),
-               std::back_insert_iterator<exvector>(new_dummy_indices), ex_is_less());
-       dummy_indices.swap(new_dummy_indices);
-}
-
-void safe_inserter::insert_new_pair(const expair &p, const ex &orig_ex)
-{
-       if(!dodummies) {
-               epv->push_back(p);
-               return;
-       }
-       exvector dummies_of_factor = get_all_dummy_indices_safely(p.rest);
-       if(dummies_of_factor.size() == 0) {
-               epv->push_back(p);
-               return;
-       }
-       sort(dummies_of_factor.begin(), dummies_of_factor.end(), ex_is_less());
-       exvector dummies_of_orig_ex = get_all_dummy_indices_safely(orig_ex);
-       sort(dummies_of_orig_ex.begin(), dummies_of_orig_ex.end(), ex_is_less());
-       exvector new_dummy_indices;
-       new_dummy_indices.reserve(dummy_indices.size());
-       set_difference(dummy_indices.begin(), dummy_indices.end(), dummies_of_orig_ex.begin(), dummies_of_orig_ex.end(),
-               std::back_insert_iterator<exvector>(new_dummy_indices), ex_is_less());
-       dummy_indices.swap(new_dummy_indices);
-       ex newfactor = rename_dummy_indices_uniquely(dummy_indices, dummies_of_factor, p.rest);
-       update_dummy_indices(dummies_of_factor);
-       epv -> push_back(expair(newfactor, p.coeff));
-}
-
 /** Member-wise substitute in this sequence.
  *
  *  @see expairseq::subs()
@@ -1720,27 +1711,22 @@ std::auto_ptr<epvector> expairseq::subschildren(const exmap & m, unsigned option
                        if (!are_ex_trivially_equal(orig_ex, subsed_ex)) {
 
                                // Something changed, copy seq, subs and return it
-                               safe_inserter s(*this, options & subs_options::no_index_renaming);
+                               std::auto_ptr<epvector> s(new epvector);
+                               s->reserve(seq.size());
 
                                // Copy parts of seq which are known not to have changed
-                               for(epvector::const_iterator i=seq.begin(); i!=cit; ++i)
-                                       s.insert_old_pair(*i);
+                               s->insert(s->begin(), seq.begin(), cit);
 
                                // Copy first changed element
-                               s.insert_new_pair(split_ex_to_pair(subsed_ex), orig_ex);
+                               s->push_back(split_ex_to_pair(subsed_ex));
                                ++cit;
 
                                // Copy rest
                                while (cit != last) {
-                                       ex orig_ex = recombine_pair_to_ex(*cit);
-                                       ex subsed_ex = orig_ex.subs(m, options);
-                                       if(are_ex_trivially_equal(orig_ex, subsed_ex))
-                                               s.insert_old_pair(*cit);
-                                       else
-                                               s.insert_new_pair(split_ex_to_pair(subsed_ex), orig_ex);
+                                       s->push_back(split_ex_to_pair(recombine_pair_to_ex(*cit).subs(m, options)));
                                        ++cit;
                                }
-                               return s.getseq();
+                               return s;
                        }
 
                        ++cit;
@@ -1756,27 +1742,22 @@ std::auto_ptr<epvector> expairseq::subschildren(const exmap & m, unsigned option
                        if (!are_ex_trivially_equal(cit->rest, subsed_ex)) {
                        
                                // Something changed, copy seq, subs and return it
-                               safe_inserter s(*this, options & subs_options::no_index_renaming);
+                               std::auto_ptr<epvector> s(new epvector);
+                               s->reserve(seq.size());
 
                                // Copy parts of seq which are known not to have changed
-                               for(epvector::const_iterator i=seq.begin(); i!=cit; ++i)
-                                       s.insert_old_pair(*i);
+                               s->insert(s->begin(), seq.begin(), cit);
                        
                                // Copy first changed element
-                               s.insert_new_pair(combine_ex_with_coeff_to_pair(subsed_ex, cit->coeff), cit->rest);
+                               s->push_back(combine_ex_with_coeff_to_pair(subsed_ex, cit->coeff));
                                ++cit;
 
                                // Copy rest
                                while (cit != last) {
-                                       const ex &orig_ex = cit->rest;
-                                       const ex &subsed_ex = cit->rest.subs(m, options);
-                                       if(are_ex_trivially_equal(orig_ex, subsed_ex))
-                                               s.insert_old_pair(*cit);
-                                       else
-                                               s.insert_new_pair(combine_ex_with_coeff_to_pair(subsed_ex, cit->coeff), orig_ex);
+                                       s->push_back(combine_ex_with_coeff_to_pair(cit->rest.subs(m, options), cit->coeff));
                                        ++cit;
                                }
-                               return s.getseq();
+                               return s;
                        }
 
                        ++cit;