* Implementation of GiNaC's products of expressions. */
/*
- * GiNaC Copyright (C) 1999-2007 Johannes Gutenberg University Mainz, Germany
+ * GiNaC Copyright (C) 1999-2008 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
#include "lst.h"
#include "archive.h"
#include "utils.h"
+#include "symbol.h"
#include "compiler.h"
namespace GiNaC {
// XXX: What is the best way to check if the polynomial is a primitive?
numeric c = i->rest.integer_content();
- const numeric& lead_coeff =
- ex_to<numeric>(ex_to<add>(i->rest).seq.begin()->coeff).div_dyn(c);
+ const numeric lead_coeff =
+ ex_to<numeric>(ex_to<add>(i->rest).seq.begin()->coeff).div(c);
const bool canonicalizable = lead_coeff.is_integer();
// XXX: The main variable is chosen in a random way, so this code
ex mul::expand(unsigned options) const
{
+ {
+ // trivial case: expanding the monomial (~ 30% of all calls)
+ epvector::const_iterator i = seq.begin(), seq_end = seq.end();
+ while ((i != seq.end()) && is_a<symbol>(i->rest) && i->coeff.info(info_flags::integer))
+ ++i;
+ if (i == seq_end) {
+ setflag(status_flags::expanded);
+ return *this;
+ }
+ }
+
+ // do not rename indices if the object has no indices at all
+ if ((!(options & expand_options::expand_rename_idx)) &&
+ this->info(info_flags::has_indices))
+ options |= expand_options::expand_rename_idx;
+
+ const bool skip_idx_rename = !(options & expand_options::expand_rename_idx);
+
// First, expand the children
std::auto_ptr<epvector> expanded_seqp = expandchildren(options);
const epvector & expanded_seq = (expanded_seqp.get() ? *expanded_seqp : seq);
ex tmp_accu = (new add(distrseq, add1.overall_coeff*add2.overall_coeff))->setflag(status_flags::dynallocated);
exvector add1_dummy_indices, add2_dummy_indices, add_indices;
+ lst dummy_subs;
- for (epvector::const_iterator i=add1begin; i!=add1end; ++i) {
- add_indices = get_all_dummy_indices_safely(i->rest);
- add1_dummy_indices.insert(add1_dummy_indices.end(), add_indices.begin(), add_indices.end());
- }
- for (epvector::const_iterator i=add2begin; i!=add2end; ++i) {
- add_indices = get_all_dummy_indices_safely(i->rest);
- add2_dummy_indices.insert(add2_dummy_indices.end(), add_indices.begin(), add_indices.end());
- }
+ if (!skip_idx_rename) {
+ for (epvector::const_iterator i=add1begin; i!=add1end; ++i) {
+ add_indices = get_all_dummy_indices_safely(i->rest);
+ add1_dummy_indices.insert(add1_dummy_indices.end(), add_indices.begin(), add_indices.end());
+ }
+ for (epvector::const_iterator i=add2begin; i!=add2end; ++i) {
+ add_indices = get_all_dummy_indices_safely(i->rest);
+ add2_dummy_indices.insert(add2_dummy_indices.end(), add_indices.begin(), add_indices.end());
+ }
- sort(add1_dummy_indices.begin(), add1_dummy_indices.end(), ex_is_less());
- sort(add2_dummy_indices.begin(), add2_dummy_indices.end(), ex_is_less());
- lst dummy_subs = rename_dummy_indices_uniquely(add1_dummy_indices, add2_dummy_indices);
+ sort(add1_dummy_indices.begin(), add1_dummy_indices.end(), ex_is_less());
+ sort(add2_dummy_indices.begin(), add2_dummy_indices.end(), ex_is_less());
+ dummy_subs = rename_dummy_indices_uniquely(add1_dummy_indices, add2_dummy_indices);
+ }
// Multiply explicitly all non-numeric terms of add1 and add2:
for (epvector::const_iterator i2=add2begin; i2!=add2end; ++i2) {
// We really have to combine terms here in order to compactify
// the result. Otherwise it would become waayy tooo bigg.
- numeric oc;
- distrseq.clear();
- ex i2_new = (dummy_subs.op(0).nops()>0?
- i2->rest.subs((lst)dummy_subs.op(0), (lst)dummy_subs.op(1), subs_options::no_pattern) : i2->rest);
+ numeric oc(*_num0_p);
+ epvector distrseq2;
+ distrseq2.reserve(add1.seq.size());
+ const ex i2_new = (skip_idx_rename || (dummy_subs.op(0).nops() == 0) ?
+ i2->rest :
+ i2->rest.subs(ex_to<lst>(dummy_subs.op(0)),
+ ex_to<lst>(dummy_subs.op(1)), subs_options::no_pattern));
for (epvector::const_iterator i1=add1begin; i1!=add1end; ++i1) {
// Don't push_back expairs which might have a rest that evaluates to a numeric,
// since that would violate an invariant of expairseq:
if (is_exactly_a<numeric>(rest)) {
oc += ex_to<numeric>(rest).mul(ex_to<numeric>(i1->coeff).mul(ex_to<numeric>(i2->coeff)));
} else {
- distrseq.push_back(expair(rest, ex_to<numeric>(i1->coeff).mul_dyn(ex_to<numeric>(i2->coeff))));
+ distrseq2.push_back(expair(rest, ex_to<numeric>(i1->coeff).mul_dyn(ex_to<numeric>(i2->coeff))));
}
}
- tmp_accu += (new add(distrseq, oc))->setflag(status_flags::dynallocated);
- }
+ tmp_accu += (new add(distrseq2, oc))->setflag(status_flags::dynallocated);
+ }
last_expanded = tmp_accu;
-
} else {
if (!last_expanded.is_equal(_ex1))
non_adds.push_back(split_ex_to_pair(last_expanded));
size_t n = last_expanded.nops();
exvector distrseq;
distrseq.reserve(n);
- exvector va = get_all_dummy_indices_safely(mul(non_adds));
- sort(va.begin(), va.end(), ex_is_less());
+ exvector va;
+ if (! skip_idx_rename) {
+ va = get_all_dummy_indices_safely(mul(non_adds));
+ sort(va.begin(), va.end(), ex_is_less());
+ }
for (size_t i=0; i<n; ++i) {
epvector factors = non_adds;
- factors.push_back(split_ex_to_pair(rename_dummy_indices_uniquely(va, last_expanded.op(i))));
+ if (skip_idx_rename)
+ factors.push_back(split_ex_to_pair(last_expanded.op(i)));
+ else
+ factors.push_back(split_ex_to_pair(rename_dummy_indices_uniquely(va, last_expanded.op(i))));
ex term = (new mul(factors, overall_coeff))->setflag(status_flags::dynallocated);
if (can_be_further_expanded(term)) {
distrseq.push_back(term.expand());
git://www.ginac.de / ginac.git / blobdiff