* Implementation of sequences of expression pairs. */
/*
- * GiNaC Copyright (C) 1999-2008 Johannes Gutenberg University Mainz, Germany
+ * GiNaC Copyright (C) 1999-2015 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
-#include <iostream>
-#include <algorithm>
-#include <string>
-#include <stdexcept>
-#include <iterator>
-
#include "expairseq.h"
#include "lst.h"
#include "add.h"
#include "archive.h"
#include "operators.h"
#include "utils.h"
+#include "hash_seed.h"
#include "indexed.h"
-#if EXPAIRSEQ_USE_HASHTAB
-#include <cmath>
-#endif // EXPAIRSEQ_USE_HASHTAB
+#include <algorithm>
+#include <iostream>
+#include <iterator>
+#include <stdexcept>
+#include <string>
namespace GiNaC {
// public
-expairseq::expairseq() : inherited(&expairseq::tinfo_static)
-#if EXPAIRSEQ_USE_HASHTAB
- , hashtabsize(0)
-#endif // EXPAIRSEQ_USE_HASHTAB
+expairseq::expairseq()
{}
// protected
-#if 0
-/** For use by copy ctor and assignment operator. */
-void expairseq::copy(const expairseq &other)
-{
- seq = other.seq;
- overall_coeff = other.overall_coeff;
-#if EXPAIRSEQ_USE_HASHTAB
- // copy hashtab
- hashtabsize = other.hashtabsize;
- if (hashtabsize!=0) {
- hashmask = other.hashmask;
- hashtab.resize(hashtabsize);
- epvector::const_iterator osb = other.seq.begin();
- for (unsigned i=0; i<hashtabsize; ++i) {
- hashtab[i].clear();
- for (epplist::const_iterator cit=other.hashtab[i].begin();
- cit!=other.hashtab[i].end(); ++cit) {
- hashtab[i].push_back(seq.begin()+((*cit)-osb));
- }
- }
- } else {
- hashtab.clear();
- }
-#endif // EXPAIRSEQ_USE_HASHTAB
-}
-#endif
-
//////////
// other constructors
//////////
-expairseq::expairseq(const ex &lh, const ex &rh) : inherited(&expairseq::tinfo_static)
+expairseq::expairseq(const ex &lh, const ex &rh)
{
construct_from_2_ex(lh,rh);
GINAC_ASSERT(is_canonical());
}
-expairseq::expairseq(const exvector &v) : inherited(&expairseq::tinfo_static)
+expairseq::expairseq(const exvector &v)
{
construct_from_exvector(v);
GINAC_ASSERT(is_canonical());
}
expairseq::expairseq(const epvector &v, const ex &oc, bool do_index_renaming)
- : inherited(&expairseq::tinfo_static), overall_coeff(oc)
+ : overall_coeff(oc)
{
GINAC_ASSERT(is_a<numeric>(oc));
construct_from_epvector(v, do_index_renaming);
}
expairseq::expairseq(std::auto_ptr<epvector> vp, const ex &oc, bool do_index_renaming)
- : inherited(&expairseq::tinfo_static), overall_coeff(oc)
+ : overall_coeff(oc)
{
GINAC_ASSERT(vp.get()!=0);
GINAC_ASSERT(is_a<numeric>(oc));
// archiving
//////////
-expairseq::expairseq(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
-#if EXPAIRSEQ_USE_HASHTAB
- , hashtabsize(0)
-#endif
+void expairseq::read_archive(const archive_node &n, lst &sym_lst)
{
+ inherited::read_archive(n, sym_lst);
archive_node::archive_node_cit first = n.find_first("rest");
archive_node::archive_node_cit last = n.find_last("coeff");
++last;
n.add_ex("overall_coeff", overall_coeff);
}
-DEFAULT_UNARCHIVE(expairseq)
//////////
// functions overriding virtual functions from base classes
overall_coeff.print(c, level + c.delta_indent);
}
c.s << std::string(level + c.delta_indent,' ') << "=====" << std::endl;
-#if EXPAIRSEQ_USE_HASHTAB
- c.s << std::string(level + c.delta_indent,' ')
- << "hashtab size " << hashtabsize << std::endl;
- if (hashtabsize == 0) return;
-#define MAXCOUNT 5
- unsigned count[MAXCOUNT+1];
- for (int i=0; i<MAXCOUNT+1; ++i)
- count[i] = 0;
- unsigned this_bin_fill;
- unsigned cum_fill_sq = 0;
- unsigned cum_fill = 0;
- for (unsigned i=0; i<hashtabsize; ++i) {
- this_bin_fill = 0;
- if (hashtab[i].size() > 0) {
- c.s << std::string(level + c.delta_indent, ' ')
- << "bin " << i << " with entries ";
- for (epplist::const_iterator it=hashtab[i].begin();
- it!=hashtab[i].end(); ++it) {
- c.s << *it-seq.begin() << " ";
- ++this_bin_fill;
- }
- c.s << std::endl;
- cum_fill += this_bin_fill;
- cum_fill_sq += this_bin_fill*this_bin_fill;
- }
- if (this_bin_fill<MAXCOUNT)
- ++count[this_bin_fill];
- else
- ++count[MAXCOUNT];
- }
- unsigned fact = 1;
- double cum_prob = 0;
- double lambda = (1.0*seq.size()) / hashtabsize;
- for (int k=0; k<MAXCOUNT; ++k) {
- if (k>0)
- fact *= k;
- double prob = std::pow(lambda,k)/fact * std::exp(-lambda);
- cum_prob += prob;
- c.s << std::string(level + c.delta_indent, ' ') << "bins with " << k << " entries: "
- << int(1000.0*count[k]/hashtabsize)/10.0 << "% (expected: "
- << int(prob*1000)/10.0 << ")" << std::endl;
- }
- c.s << std::string(level + c.delta_indent, ' ') << "bins with more entries: "
- << int(1000.0*count[MAXCOUNT]/hashtabsize)/10.0 << "% (expected: "
- << int((1-cum_prob)*1000)/10.0 << ")" << std::endl;
-
- c.s << std::string(level + c.delta_indent, ' ') << "variance: "
- << 1.0/hashtabsize*cum_fill_sq-(1.0/hashtabsize*cum_fill)*(1.0/hashtabsize*cum_fill)
- << std::endl;
- c.s << std::string(level + c.delta_indent, ' ') << "average fill: "
- << (1.0*cum_fill)/hashtabsize
- << " (should be equal to " << (1.0*seq.size())/hashtabsize << ")" << std::endl;
-#endif // EXPAIRSEQ_USE_HASHTAB
}
bool expairseq::info(unsigned inf) const
return *this;
}
ex result = thisexpairseq(newepv ? *newepv : seq, x);
- if (newepv) {
- delete newepv;
- }
+ delete newepv;
return result;
}
-bool expairseq::is_polynomial(const ex & var) const
-{
- if (!is_exactly_a<add>(*this) && !is_exactly_a<mul>(*this))
- return basic::is_polynomial(var);
- for (epvector::const_iterator i=seq.begin(); i!=seq.end(); ++i) {
- if (!(i->rest).is_polynomial(var))
- return false;
- }
- return true;
-}
-
-bool expairseq::match(const ex & pattern, lst & repl_lst) const
+bool expairseq::match(const ex & pattern, exmap & repl_lst) const
{
// This differs from basic::match() because we want "a+b+c+d" to
// match "d+*+b" with "*" being "a+c", and we want to honor commutativity
- if (this->tinfo() == ex_to<basic>(pattern).tinfo()) {
+ if (typeid(*this) == typeid(ex_to<basic>(pattern))) {
// Check whether global wildcard (one that matches the "rest of the
// expression", like "*" above) is present
}
}
+ // Even if the expression does not match the pattern, some of
+ // its subexpressions could match it. For example, x^5*y^(-1)
+ // does not match the pattern $0^5, but its subexpression x^5
+ // does. So, save repl_lst in order to not add bogus entries.
+ exmap tmp_repl = repl_lst;
+
// Unfortunately, this is an O(N^2) operation because we can't
// sort the pattern in a useful way...
continue;
exvector::iterator it = ops.begin(), itend = ops.end();
while (it != itend) {
- lst::const_iterator last_el = repl_lst.end();
- --last_el;
- if (it->match(p, repl_lst)) {
+ if (it->match(p, tmp_repl)) {
ops.erase(it);
goto found;
}
- while(true) {
- lst::const_iterator next_el = last_el;
- ++next_el;
- if(next_el == repl_lst.end())
- break;
- else
- repl_lst.remove_last();
- }
++it;
}
return false; // no match found
for (size_t i=0; i<num; i++)
vp->push_back(split_ex_to_pair(ops[i]));
ex rest = thisexpairseq(vp, default_overall_coeff());
- for (lst::const_iterator it = repl_lst.begin(); it != repl_lst.end(); ++it) {
- if (it->op(0).is_equal(global_wildcard))
- return rest.is_equal(it->op(1));
+ for (exmap::const_iterator it = tmp_repl.begin(); it != tmp_repl.end(); ++it) {
+ if (it->first.is_equal(global_wildcard)) {
+ if (rest.is_equal(it->second)) {
+ repl_lst = tmp_repl;
+ return true;
+ }
+ return false;
+ }
}
- repl_lst.append(global_wildcard == rest);
+ repl_lst = tmp_repl;
+ repl_lst[global_wildcard] = rest;
return true;
} else {
// No global wildcard, then the match fails if there are any
// unmatched terms left
- return ops.empty();
+ if (ops.empty()) {
+ repl_lst = tmp_repl;
+ return true;
+ }
+ return false;
}
}
return inherited::match(pattern, repl_lst);
{
std::auto_ptr<epvector> vp = subschildren(m, options);
if (vp.get())
- return ex_to<basic>(thisexpairseq(vp, overall_coeff, true));
+ return ex_to<basic>(thisexpairseq(vp, overall_coeff, (options & subs_options::no_index_renaming) == 0));
else if ((options & subs_options::algebraic) && is_exactly_a<mul>(*this))
return static_cast<const mul *>(this)->algebraic_subs_mul(m, options);
else
if (cmpval!=0)
return cmpval;
-#if EXPAIRSEQ_USE_HASHTAB
- GINAC_ASSERT(hashtabsize==o.hashtabsize);
- if (hashtabsize==0) {
-#endif // EXPAIRSEQ_USE_HASHTAB
- epvector::const_iterator cit1 = seq.begin();
- epvector::const_iterator cit2 = o.seq.begin();
- epvector::const_iterator last1 = seq.end();
- epvector::const_iterator last2 = o.seq.end();
+ epvector::const_iterator cit1 = seq.begin();
+ epvector::const_iterator cit2 = o.seq.begin();
+ epvector::const_iterator last1 = seq.end();
+ epvector::const_iterator last2 = o.seq.end();
- for (; (cit1!=last1)&&(cit2!=last2); ++cit1, ++cit2) {
- cmpval = (*cit1).compare(*cit2);
- if (cmpval!=0) return cmpval;
- }
+ for (; (cit1!=last1)&&(cit2!=last2); ++cit1, ++cit2) {
+ cmpval = (*cit1).compare(*cit2);
+ if (cmpval!=0) return cmpval;
+ }
- GINAC_ASSERT(cit1==last1);
- GINAC_ASSERT(cit2==last2);
+ GINAC_ASSERT(cit1==last1);
+ GINAC_ASSERT(cit2==last2);
- return 0;
-#if EXPAIRSEQ_USE_HASHTAB
- }
-
- // compare number of elements in each hashtab entry
- for (unsigned i=0; i<hashtabsize; ++i) {
- unsigned cursize=hashtab[i].size();
- if (cursize != o.hashtab[i].size())
- return (cursize < o.hashtab[i].size()) ? -1 : 1;
- }
-
- // compare individual (sorted) hashtab entries
- for (unsigned i=0; i<hashtabsize; ++i) {
- unsigned sz = hashtab[i].size();
- if (sz>0) {
- const epplist &eppl1 = hashtab[i];
- const epplist &eppl2 = o.hashtab[i];
- epplist::const_iterator it1 = eppl1.begin();
- epplist::const_iterator it2 = eppl2.begin();
- while (it1!=eppl1.end()) {
- cmpval = (*(*it1)).compare(*(*it2));
- if (cmpval!=0)
- return cmpval;
- ++it1;
- ++it2;
- }
- }
- }
-
- return 0; // equal
-#endif // EXPAIRSEQ_USE_HASHTAB
+ return 0;
}
bool expairseq::is_equal_same_type(const basic &other) const
if (!overall_coeff.is_equal(o.overall_coeff))
return false;
-#if EXPAIRSEQ_USE_HASHTAB
- // compare number of elements in each hashtab entry
- if (hashtabsize!=o.hashtabsize) {
- std::cout << "this:" << std::endl;
- print(print_tree(std::cout));
- std::cout << "other:" << std::endl;
- other.print(print_tree(std::cout));
- }
+ epvector::const_iterator cit1 = seq.begin();
+ epvector::const_iterator cit2 = o.seq.begin();
+ epvector::const_iterator last1 = seq.end();
- GINAC_ASSERT(hashtabsize==o.hashtabsize);
-
- if (hashtabsize==0) {
-#endif // EXPAIRSEQ_USE_HASHTAB
- epvector::const_iterator cit1 = seq.begin();
- epvector::const_iterator cit2 = o.seq.begin();
- epvector::const_iterator last1 = seq.end();
-
- while (cit1!=last1) {
- if (!(*cit1).is_equal(*cit2)) return false;
- ++cit1;
- ++cit2;
- }
-
- return true;
-#if EXPAIRSEQ_USE_HASHTAB
- }
-
- for (unsigned i=0; i<hashtabsize; ++i) {
- if (hashtab[i].size() != o.hashtab[i].size())
- return false;
+ while (cit1!=last1) {
+ if (!(*cit1).is_equal(*cit2)) return false;
+ ++cit1;
+ ++cit2;
}
- // compare individual sorted hashtab entries
- for (unsigned i=0; i<hashtabsize; ++i) {
- unsigned sz = hashtab[i].size();
- if (sz>0) {
- const epplist &eppl1 = hashtab[i];
- const epplist &eppl2 = o.hashtab[i];
- epplist::const_iterator it1 = eppl1.begin();
- epplist::const_iterator it2 = eppl2.begin();
- while (it1!=eppl1.end()) {
- if (!(*(*it1)).is_equal(*(*it2))) return false;
- ++it1;
- ++it2;
- }
- }
- }
-
return true;
-#endif // EXPAIRSEQ_USE_HASHTAB
}
unsigned expairseq::return_type() const
unsigned expairseq::calchash() const
{
- unsigned v = golden_ratio_hash((p_int)this->tinfo());
+ unsigned v = make_hash_seed(typeid(*this));
epvector::const_iterator i = seq.begin();
const epvector::const_iterator end = seq.end();
while (i != end) {
v ^= i->rest.gethash();
-#if !EXPAIRSEQ_USE_HASHTAB
// rotation spoils commutativity!
v = rotate_left(v);
v ^= i->coeff.gethash();
-#endif // !EXPAIRSEQ_USE_HASHTAB
++i;
}
* has (at least) two possible different semantics but we want to inherit
* methods thus avoiding code duplication. Sometimes a method in expairseq
* has to create a new one of the same semantics, which cannot be done by a
- * ctor because the name (add, mul,...) is unknown on the expaiseq level. In
+ * ctor because the name (add, mul,...) is unknown on the expairseq 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, bool do_index_renaming) const
bool expairseq::expair_needs_further_processing(epp it)
{
-#if EXPAIRSEQ_USE_HASHTAB
- //# error "FIXME: expair_needs_further_processing not yet implemented for hashtabs, sorry. A.F."
-#endif // EXPAIRSEQ_USE_HASHTAB
return false;
}
v.push_back(lh);
v.push_back(rh);
construct_from_exvector(v);
-#if EXPAIRSEQ_USE_HASHTAB
- GINAC_ASSERT((hashtabsize==0)||(hashtabsize>=minhashtabsize));
- GINAC_ASSERT(hashtabsize==calc_hashtabsize(seq.size()));
-#endif // EXPAIRSEQ_USE_HASHTAB
}
void expairseq::construct_from_2_ex(const ex &lh, const ex &rh)
{
- if (ex_to<basic>(lh).tinfo()==this->tinfo()) {
- if (ex_to<basic>(rh).tinfo()==this->tinfo()) {
-#if EXPAIRSEQ_USE_HASHTAB
- unsigned totalsize = ex_to<expairseq>(lh).seq.size() +
- ex_to<expairseq>(rh).seq.size();
- if (calc_hashtabsize(totalsize)!=0) {
- construct_from_2_ex_via_exvector(lh,rh);
- } else {
-#endif // EXPAIRSEQ_USE_HASHTAB
- if (is_a<mul>(lh) && lh.info(info_flags::has_indices) &&
- rh.info(info_flags::has_indices)) {
- ex newrh=rename_dummy_indices_uniquely(lh, rh);
- construct_from_2_expairseq(ex_to<expairseq>(lh),
- ex_to<expairseq>(newrh));
- }
- else
- construct_from_2_expairseq(ex_to<expairseq>(lh),
- ex_to<expairseq>(rh));
-#if EXPAIRSEQ_USE_HASHTAB
+ if (typeid(ex_to<basic>(lh)) == typeid(*this)) {
+ if (typeid(ex_to<basic>(rh)) == typeid(*this)) {
+ if (is_a<mul>(lh) && lh.info(info_flags::has_indices) &&
+ rh.info(info_flags::has_indices)) {
+ ex newrh=rename_dummy_indices_uniquely(lh, rh);
+ construct_from_2_expairseq(ex_to<expairseq>(lh),
+ ex_to<expairseq>(newrh));
}
-#endif // EXPAIRSEQ_USE_HASHTAB
+ else
+ construct_from_2_expairseq(ex_to<expairseq>(lh),
+ ex_to<expairseq>(rh));
return;
} else {
-#if EXPAIRSEQ_USE_HASHTAB
- unsigned totalsize = ex_to<expairseq>(lh).seq.size()+1;
- if (calc_hashtabsize(totalsize)!=0) {
- construct_from_2_ex_via_exvector(lh, rh);
- } else {
-#endif // EXPAIRSEQ_USE_HASHTAB
- construct_from_expairseq_ex(ex_to<expairseq>(lh), rh);
-#if EXPAIRSEQ_USE_HASHTAB
- }
-#endif // EXPAIRSEQ_USE_HASHTAB
+ construct_from_expairseq_ex(ex_to<expairseq>(lh), rh);
return;
}
- } else if (ex_to<basic>(rh).tinfo()==this->tinfo()) {
-#if EXPAIRSEQ_USE_HASHTAB
- unsigned totalsize=ex_to<expairseq>(rh).seq.size()+1;
- if (calc_hashtabsize(totalsize)!=0) {
- construct_from_2_ex_via_exvector(lh,rh);
- } else {
-#endif // EXPAIRSEQ_USE_HASHTAB
- construct_from_expairseq_ex(ex_to<expairseq>(rh),lh);
-#if EXPAIRSEQ_USE_HASHTAB
- }
-#endif // EXPAIRSEQ_USE_HASHTAB
- return;
- }
-
-#if EXPAIRSEQ_USE_HASHTAB
- if (calc_hashtabsize(2)!=0) {
- construct_from_2_ex_via_exvector(lh,rh);
+ } else if (typeid(ex_to<basic>(rh)) == typeid(*this)) {
+ construct_from_expairseq_ex(ex_to<expairseq>(rh),lh);
return;
}
- hashtabsize = 0;
-#endif // EXPAIRSEQ_USE_HASHTAB
if (is_exactly_a<numeric>(lh)) {
if (is_exactly_a<numeric>(rh)) {
}
void expairseq::construct_from_2_expairseq(const expairseq &s1,
- const expairseq &s2)
+ const expairseq &s2)
{
combine_overall_coeff(s1.overall_coeff);
combine_overall_coeff(s2.overall_coeff);
}
void expairseq::construct_from_expairseq_ex(const expairseq &s,
- const ex &e)
+ const ex &e)
{
combine_overall_coeff(s.overall_coeff);
if (is_exactly_a<numeric>(e)) {
{
// 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())
+ // +(...,x,*(x,c1),*(x,c2)) -> +(...,*(x,1+c1+c2)) (c1, c2 numeric)
// (same for (+,*) -> (*,^)
make_flat(v);
-#if EXPAIRSEQ_USE_HASHTAB
- combine_same_terms();
-#else
canonicalize();
combine_same_terms_sorted_seq();
-#endif // EXPAIRSEQ_USE_HASHTAB
}
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 (+,*) -> (*,^)
+ // +(...,x,*(x,c1),*(x,c2)) -> +(...,*(x,1+c1+c2)) (c1, c2 numeric)
+ // same for (+,*) -> (*,^)
make_flat(v, do_index_renaming);
-#if EXPAIRSEQ_USE_HASHTAB
- combine_same_terms();
-#else
canonicalize();
combine_same_terms_sorted_seq();
-#endif // EXPAIRSEQ_USE_HASHTAB
}
/** Combine this expairseq with argument exvector.
cit = v.begin();
while (cit!=v.end()) {
- if (ex_to<basic>(*cit).tinfo()==this->tinfo()) {
+ if (typeid(ex_to<basic>(*cit)) == typeid(*this)) {
++nexpairseqs;
noperands += ex_to<expairseq>(*cit).seq.size();
}
make_flat_inserter mf(v, do_idx_rename);
cit = v.begin();
while (cit!=v.end()) {
- if (ex_to<basic>(*cit).tinfo()==this->tinfo()) {
+ if (typeid(ex_to<basic>(*cit)) == typeid(*this)) {
ex newfactor = mf.handle_factor(*cit, _ex1);
const expairseq &subseqref = ex_to<expairseq>(newfactor);
combine_overall_coeff(subseqref.overall_coeff);
cit = v.begin();
while (cit!=v.end()) {
- if (ex_to<basic>(cit->rest).tinfo()==this->tinfo()) {
+ if (typeid(ex_to<basic>(cit->rest)) == typeid(*this)) {
++nexpairseqs;
noperands += ex_to<expairseq>(cit->rest).seq.size();
}
// copy elements and split off numerical part
cit = v.begin();
while (cit!=v.end()) {
- if (ex_to<basic>(cit->rest).tinfo()==this->tinfo() &&
+ if ((typeid(ex_to<basic>(cit->rest)) == typeid(*this)) &&
this->can_make_flat(*cit)) {
ex newrest = mf.handle_factor(cit->rest, cit->coeff);
const expairseq &subseqref = ex_to<expairseq>(newrest);
}
}
-#if EXPAIRSEQ_USE_HASHTAB
-
-unsigned expairseq::calc_hashtabsize(unsigned sz) const
-{
- unsigned size;
- unsigned nearest_power_of_2 = 1 << log2(sz);
- // if (nearest_power_of_2 < maxhashtabsize/hashtabfactor) {
- // size = nearest_power_of_2*hashtabfactor;
- size = nearest_power_of_2/hashtabfactor;
- if (size<minhashtabsize)
- return 0;
-
- // hashtabsize must be a power of 2
- GINAC_ASSERT((1U << log2(size))==size);
- return size;
-}
-
-unsigned expairseq::calc_hashindex(const ex &e) const
-{
- // calculate hashindex
- unsigned hashindex;
- if (is_a<numeric>(e)) {
- hashindex = hashmask;
- } else {
- hashindex = e.gethash() & hashmask;
- // last hashtab entry is reserved for numerics
- if (hashindex==hashmask) hashindex = 0;
- }
- GINAC_ASSERT((hashindex<hashtabsize)||(hashtabsize==0));
- return hashindex;
-}
-
-void expairseq::shrink_hashtab()
-{
- unsigned new_hashtabsize;
- while (hashtabsize!=(new_hashtabsize=calc_hashtabsize(seq.size()))) {
- GINAC_ASSERT(new_hashtabsize<hashtabsize);
- if (new_hashtabsize==0) {
- hashtab.clear();
- hashtabsize = 0;
- canonicalize();
- return;
- }
-
- // shrink by a factor of 2
- unsigned half_hashtabsize = hashtabsize/2;
- for (unsigned i=0; i<half_hashtabsize-1; ++i)
- hashtab[i].merge(hashtab[i+half_hashtabsize],epp_is_less());
- // special treatment for numeric hashes
- hashtab[0].merge(hashtab[half_hashtabsize-1],epp_is_less());
- hashtab[half_hashtabsize-1] = hashtab[hashtabsize-1];
- hashtab.resize(half_hashtabsize);
- hashtabsize = half_hashtabsize;
- hashmask = hashtabsize-1;
- }
-}
-
-void expairseq::remove_hashtab_entry(epvector::const_iterator element)
-{
- if (hashtabsize==0)
- return; // nothing to do
-
- // calculate hashindex of element to be deleted
- unsigned hashindex = calc_hashindex((*element).rest);
-
- // find it in hashtab and remove it
- epplist &eppl = hashtab[hashindex];
- epplist::iterator epplit = eppl.begin();
- bool erased = false;
- while (epplit!=eppl.end()) {
- if (*epplit == element) {
- eppl.erase(epplit);
- erased = true;
- break;
- }
- ++epplit;
- }
- if (!erased) {
- std::cout << "tried to erase " << element-seq.begin() << std::endl;
- std::cout << "size " << seq.end()-seq.begin() << std::endl;
-
- unsigned hashindex = calc_hashindex(element->rest);
- epplist &eppl = hashtab[hashindex];
- epplist::iterator epplit = eppl.begin();
- bool erased = false;
- while (epplit!=eppl.end()) {
- if (*epplit == element) {
- eppl.erase(epplit);
- erased = true;
- break;
- }
- ++epplit;
- }
- GINAC_ASSERT(erased);
- }
- GINAC_ASSERT(erased);
-}
-
-void expairseq::move_hashtab_entry(epvector::const_iterator oldpos,
- epvector::iterator newpos)
-{
- GINAC_ASSERT(hashtabsize!=0);
-
- // calculate hashindex of element which was moved
- unsigned hashindex=calc_hashindex((*newpos).rest);
-
- // find it in hashtab and modify it
- epplist &eppl = hashtab[hashindex];
- epplist::iterator epplit = eppl.begin();
- while (epplit!=eppl.end()) {
- if (*epplit == oldpos) {
- *epplit = newpos;
- break;
- }
- ++epplit;
- }
- GINAC_ASSERT(epplit!=eppl.end());
-}
-
-void expairseq::sorted_insert(epplist &eppl, epvector::const_iterator elem)
-{
- epplist::const_iterator current = eppl.begin();
- while ((current!=eppl.end()) && ((*current)->is_less(*elem))) {
- ++current;
- }
- eppl.insert(current,elem);
-}
-
-void expairseq::build_hashtab_and_combine(epvector::iterator &first_numeric,
- epvector::iterator &last_non_zero,
- std::vector<bool> &touched,
- unsigned &number_of_zeroes)
-{
- epp current = seq.begin();
-
- while (current!=first_numeric) {
- if (is_exactly_a<numeric>(current->rest)) {
- --first_numeric;
- iter_swap(current,first_numeric);
- } else {
- // calculate hashindex
- unsigned currenthashindex = calc_hashindex(current->rest);
-
- // test if there is already a matching expair in the hashtab-list
- epplist &eppl=hashtab[currenthashindex];
- epplist::iterator epplit = eppl.begin();
- while (epplit!=eppl.end()) {
- if (current->rest.is_equal((*epplit)->rest))
- break;
- ++epplit;
- }
- if (epplit==eppl.end()) {
- // no matching expair found, append this to end of list
- sorted_insert(eppl,current);
- ++current;
- } else {
- // epplit points to a matching expair, combine it with current
- (*epplit)->coeff = ex_to<numeric>((*epplit)->coeff).
- add_dyn(ex_to<numeric>(current->coeff));
-
- // move obsolete current expair to end by swapping with last_non_zero element
- // if this was a numeric, it is swapped with the expair before first_numeric
- iter_swap(current,last_non_zero);
- --first_numeric;
- if (first_numeric!=last_non_zero) iter_swap(first_numeric,current);
- --last_non_zero;
- ++number_of_zeroes;
- // test if combined term has coeff 0 and can be removed is done later
- touched[(*epplit)-seq.begin()] = true;
- }
- }
- }
-}
-
-void expairseq::drop_coeff_0_terms(epvector::iterator &first_numeric,
- epvector::iterator &last_non_zero,
- std::vector<bool> &touched,
- unsigned &number_of_zeroes)
-{
- // move terms with coeff 0 to end and remove them from hashtab
- // check only those elements which have been touched
- epp current = seq.begin();
- size_t i = 0;
- while (current!=first_numeric) {
- if (!touched[i]) {
- ++current;
- ++i;
- } else if (!ex_to<numeric>((*current).coeff).is_zero()) {
- ++current;
- ++i;
- } else {
- remove_hashtab_entry(current);
-
- // move element to the end, unless it is already at the end
- if (current!=last_non_zero) {
- iter_swap(current,last_non_zero);
- --first_numeric;
- bool numeric_swapped = first_numeric!=last_non_zero;
- if (numeric_swapped)
- iter_swap(first_numeric,current);
- epvector::iterator changed_entry;
-
- if (numeric_swapped)
- changed_entry = first_numeric;
- else
- changed_entry = last_non_zero;
-
- --last_non_zero;
- ++number_of_zeroes;
-
- if (first_numeric!=current) {
-
- // change entry in hashtab which referred to first_numeric or last_non_zero to current
- move_hashtab_entry(changed_entry,current);
- touched[current-seq.begin()] = touched[changed_entry-seq.begin()];
- }
- } else {
- --first_numeric;
- --last_non_zero;
- ++number_of_zeroes;
- }
- }
- }
- GINAC_ASSERT(i==current-seq.begin());
-}
-
-/** True if one of the coeffs vanishes, otherwise false.
- * This would be an invariant violation, so this should only be used for
- * debugging purposes. */
-bool expairseq::has_coeff_0() const
-{
- epvector::const_iterator i = seq.begin(), end = seq.end();
- while (i != end) {
- if (i->coeff.is_zero())
- return true;
- ++i;
- }
- return false;
-}
-
-void expairseq::add_numerics_to_hashtab(epvector::iterator first_numeric,
- epvector::const_iterator last_non_zero)
-{
- if (first_numeric == seq.end()) return; // no numerics
-
- epvector::const_iterator current = first_numeric, last = last_non_zero + 1;
- while (current != last) {
- sorted_insert(hashtab[hashmask], current);
- ++current;
- }
-}
-
-void expairseq::combine_same_terms()
-{
- // combine same terms, drop term with coeff 0, move numerics to end
-
- // calculate size of hashtab
- hashtabsize = calc_hashtabsize(seq.size());
-
- // hashtabsize is a power of 2
- hashmask = hashtabsize-1;
-
- // allocate hashtab
- hashtab.clear();
- hashtab.resize(hashtabsize);
-
- if (hashtabsize==0) {
- canonicalize();
- combine_same_terms_sorted_seq();
- GINAC_ASSERT(!has_coeff_0());
- return;
- }
-
- // iterate through seq, move numerics to end,
- // fill hashtab and combine same terms
- epvector::iterator first_numeric = seq.end();
- epvector::iterator last_non_zero = seq.end()-1;
-
- size_t num = seq.size();
- std::vector<bool> touched(num);
-
- unsigned number_of_zeroes = 0;
-
- GINAC_ASSERT(!has_coeff_0());
- build_hashtab_and_combine(first_numeric,last_non_zero,touched,number_of_zeroes);
-
- // there should not be any terms with coeff 0 from the beginning,
- // so it should be safe to skip this step
- if (number_of_zeroes!=0) {
- drop_coeff_0_terms(first_numeric,last_non_zero,touched,number_of_zeroes);
- }
-
- add_numerics_to_hashtab(first_numeric,last_non_zero);
-
- // pop zero elements
- for (unsigned i=0; i<number_of_zeroes; ++i) {
- seq.pop_back();
- }
-
- // shrink hashtabsize to calculated value
- GINAC_ASSERT(!has_coeff_0());
-
- shrink_hashtab();
-
- GINAC_ASSERT(!has_coeff_0());
-}
-
-#endif // EXPAIRSEQ_USE_HASHTAB
-
/** Check if this expairseq is in sorted (canonical) form. Useful mainly for
* debugging or in assertions since being sorted is an invariance. */
bool expairseq::is_canonical() const
if (seq.size() <= 1)
return 1;
-#if EXPAIRSEQ_USE_HASHTAB
- if (hashtabsize > 0) return 1; // not canoncalized
-#endif // EXPAIRSEQ_USE_HASHTAB
-
epvector::const_iterator it = seq.begin(), itend = seq.end();
epvector::const_iterator it_last = it;
for (++it; it!=itend; it_last=it, ++it) {
// static member variables
//////////
-#if EXPAIRSEQ_USE_HASHTAB
-unsigned expairseq::maxhashtabsize = 0x4000000U;
-unsigned expairseq::minhashtabsize = 0x1000U;
-unsigned expairseq::hashtabfactor = 1;
-#endif // EXPAIRSEQ_USE_HASHTAB
-
} // namespace GiNaC
git://www.ginac.de / ginac.git / blobdiff