X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Fmul.cpp;h=2b20e9fca917c5ec9877400e6e5ee8b7607b6df8;hp=6f99c515062ff86c64a253ae9ce80adf512680bb;hb=547db2f0380c03c7d013aa8bda36aa33ff5559e1;hpb=6d7bf9ee5a7ce05cb3a23dae664e781d7325d7b8 diff --git a/ginac/mul.cpp b/ginac/mul.cpp index 6f99c515..2b20e9fc 100644 --- a/ginac/mul.cpp +++ b/ginac/mul.cpp @@ -3,7 +3,7 @@ * Implementation of GiNaC's products of expressions. */ /* - * GiNaC Copyright (C) 1999-2003 Johannes Gutenberg University Mainz, Germany + * GiNaC Copyright (C) 1999-2004 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 @@ -40,7 +40,7 @@ GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(mul, expairseq, print_func(&mul::do_print). print_func(&mul::do_print_latex). print_func(&mul::do_print_csrc). - print_func(&inherited::do_print_tree). + print_func(&mul::do_print_tree). print_func(&mul::do_print_python_repr)) @@ -94,7 +94,7 @@ mul::mul(const epvector & v, const ex & oc) mul::mul(std::auto_ptr vp, const ex & oc) { tinfo_key = TINFO_mul; - GINAC_ASSERT(vp!=0); + GINAC_ASSERT(vp.get()!=0); overall_coeff = oc; construct_from_epvector(*vp); GINAC_ASSERT(is_canonical()); @@ -672,7 +672,7 @@ int mul::compare_same_type(const basic & other) const unsigned mul::return_type() const { if (seq.empty()) { - // mul without factors: should not happen, but commutes + // mul without factors: should not happen, but commutates return return_types::commutative; } @@ -824,6 +824,20 @@ bool mul::can_make_flat(const expair & p) const return ex_to(p.coeff).is_equal(_num1); } +bool mul::can_be_further_expanded(const ex & e) +{ + if (is_exactly_a(e)) { + for (epvector::const_iterator cit = ex_to(e).seq.begin(); cit != ex_to(e).seq.end(); ++cit) { + if (is_exactly_a(cit->rest) && cit->coeff.info(info_flags::posint)) + return true; + } + } else if (is_exactly_a(e)) { + if (is_exactly_a(e.op(0)) && e.op(1).info(info_flags::posint)) + return true; + } + return false; +} + ex mul::expand(unsigned options) const { // First, expand the children @@ -833,15 +847,15 @@ ex mul::expand(unsigned options) const // Now, look for all the factors that are sums and multiply each one out // with the next one that is found while collecting the factors which are // not sums - int number_of_adds = 0; ex last_expanded = _ex1; + bool need_reexpand = false; + epvector non_adds; non_adds.reserve(expanded_seq.size()); - epvector::const_iterator cit = expanded_seq.begin(), last = expanded_seq.end(); - while (cit != last) { + + for (epvector::const_iterator cit = expanded_seq.begin(); cit != expanded_seq.end(); ++cit) { if (is_exactly_a(cit->rest) && (cit->coeff.is_equal(_ex1))) { - ++number_of_adds; if (is_exactly_a(last_expanded)) { // Expand a product of two sums, aggressive version. @@ -859,6 +873,7 @@ ex mul::expand(unsigned options) const const epvector::const_iterator add2end = add2.seq.end(); epvector distrseq; distrseq.reserve(add1.seq.size()+add2.seq.size()); + // Multiply add2 with the overall coefficient of add1 and append it to distrseq: if (!add1.overall_coeff.is_zero()) { if (add1.overall_coeff.is_equal(_ex1)) @@ -867,6 +882,7 @@ ex mul::expand(unsigned options) const for (epvector::const_iterator i=add2begin; i!=add2end; ++i) distrseq.push_back(expair(i->rest, ex_to(i->coeff).mul_dyn(ex_to(add1.overall_coeff)))); } + // Multiply add1 with the overall coefficient of add2 and append it to distrseq: if (!add2.overall_coeff.is_zero()) { if (add2.overall_coeff.is_equal(_ex1)) @@ -875,8 +891,10 @@ ex mul::expand(unsigned options) const for (epvector::const_iterator i=add1begin; i!=add1end; ++i) distrseq.push_back(expair(i->rest, ex_to(i->coeff).mul_dyn(ex_to(add2.overall_coeff)))); } + // Compute the new overall coefficient and put it together: ex tmp_accu = (new add(distrseq, add1.overall_coeff*add2.overall_coeff))->setflag(status_flags::dynallocated); + // Multiply explicitly all non-numeric terms of add1 and add2: for (epvector::const_iterator i1=add1begin; i1!=add1end; ++i1) { // We really have to combine terms here in order to compactify @@ -897,34 +915,49 @@ ex mul::expand(unsigned options) const last_expanded = tmp_accu; } else { - non_adds.push_back(split_ex_to_pair(last_expanded)); + if (!last_expanded.is_equal(_ex1)) + non_adds.push_back(split_ex_to_pair(last_expanded)); last_expanded = cit->rest; } + } else { non_adds.push_back(*cit); } - ++cit; } - + // Now the only remaining thing to do is to multiply the factors which // were not sums into the "last_expanded" sum if (is_exactly_a(last_expanded)) { - const add & finaladd = ex_to(last_expanded); + size_t n = last_expanded.nops(); exvector distrseq; - size_t n = finaladd.nops(); distrseq.reserve(n); + for (size_t i=0; i - setflag(status_flags::dynallocated | (options == 0 ? status_flags::expanded : 0))); + factors.push_back(split_ex_to_pair(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()); + else { + if (options == 0) + ex_to(term).setflag(status_flags::expanded); + distrseq.push_back(term); + } } + return ((new add(distrseq))-> setflag(status_flags::dynallocated | (options == 0 ? status_flags::expanded : 0))); } + non_adds.push_back(split_ex_to_pair(last_expanded)); - return (new mul(non_adds, overall_coeff))-> - setflag(status_flags::dynallocated | (options == 0 ? status_flags::expanded : 0)); + ex result = (new mul(non_adds, overall_coeff))->setflag(status_flags::dynallocated); + if (can_be_further_expanded(result)) { + return result.expand(); + } else { + if (options == 0) + ex_to(result).setflag(status_flags::expanded); + return result; + } }