X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Fpower.cpp;h=cbe63248afa6812b346f8c78c1c265cac73e8234;hp=10de528d06ad9cf09381b4376f61ff433ca414f6;hb=a17a77e5c3d4ec2a92804debac65c75921f0156d;hpb=9fe3a96b35a68c4f6c16c21322161dbb26118ed0 diff --git a/ginac/power.cpp b/ginac/power.cpp index 10de528d..cbe63248 100644 --- a/ginac/power.cpp +++ b/ginac/power.cpp @@ -3,7 +3,7 @@ * Implementation of GiNaC's symbolic exponentiation (basis^exponent). */ /* - * 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 @@ -59,7 +59,7 @@ typedef std::vector intvector; // default constructor ////////// -power::power() : inherited(&power::tinfo_static) { } +power::power() { } ////////// // other constructors @@ -71,8 +71,9 @@ power::power() : inherited(&power::tinfo_static) { } // archiving ////////// -power::power(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst) +void power::read_archive(const archive_node &n, lst &sym_lst) { + inherited::read_archive(n, sym_lst); n.find_ex("basis", basis, sym_lst); n.find_ex("exponent", exponent, sym_lst); } @@ -84,8 +85,6 @@ void power::archive(archive_node &n) const n.add_ex("exponent", exponent); } -DEFAULT_UNARCHIVE(power) - ////////// // functions overriding virtual functions from base classes ////////// @@ -506,8 +505,8 @@ ex power::eval(int level) const // (2*x + 6*y)^(-4) -> 1/16*(x + 3*y)^(-4) if (num_exponent->is_integer() && is_exactly_a(ebasis)) { numeric icont = ebasis.integer_content(); - const numeric& lead_coeff = - ex_to(ex_to(ebasis).seq.begin()->coeff).div_dyn(icont); + const numeric lead_coeff = + ex_to(ex_to(ebasis).seq.begin()->coeff).div(icont); const bool canonicalizable = lead_coeff.is_integer(); const bool unit_normal = lead_coeff.is_pos_integer(); @@ -635,7 +634,7 @@ bool power::has(const ex & other, unsigned options) const } // from mul.cpp -extern bool tryfactsubs(const ex &, const ex &, int &, lst &); +extern bool tryfactsubs(const ex &, const ex &, int &, exmap&); ex power::subs(const exmap & m, unsigned options) const { @@ -651,9 +650,13 @@ ex power::subs(const exmap & m, unsigned options) const for (exmap::const_iterator it = m.begin(); it != m.end(); ++it) { int nummatches = std::numeric_limits::max(); - lst repls; - if (tryfactsubs(*this, it->first, nummatches, repls)) - return (ex_to((*this) * power(it->second.subs(ex(repls), subs_options::no_pattern) / it->first.subs(ex(repls), subs_options::no_pattern), nummatches))).subs_one_level(m, options); + exmap repls; + if (tryfactsubs(*this, it->first, nummatches, repls)) { + ex anum = it->second.subs(repls, subs_options::no_pattern); + ex aden = it->first.subs(repls, subs_options::no_pattern); + ex result = (*this)*power(anum/aden, nummatches); + return (ex_to(result)).subs_one_level(m, options); + } } return subs_one_level(m, options); @@ -765,16 +768,19 @@ unsigned power::return_type() const return basis.return_type(); } -tinfo_t power::return_type_tinfo() const +return_type_t power::return_type_tinfo() const { return basis.return_type_tinfo(); } ex power::expand(unsigned options) const { - if (options == 0 && (flags & status_flags::expanded)) + if (is_a(basis) && exponent.info(info_flags::integer)) { + // A special case worth optimizing. + setflag(status_flags::expanded); return *this; - + } + const ex expanded_basis = basis.expand(options); const ex expanded_exponent = exponent.expand(options); @@ -861,7 +867,6 @@ ex power::expand_add(const add & a, int n, unsigned options) const intvector k(m-1); intvector k_cum(m-1); // k_cum[l]:=sum(i=0,l,k[l]); intvector upper_limit(m-1); - int l; for (size_t l=0; l(b)); GINAC_ASSERT(!is_exactly_a(b) || @@ -887,7 +892,7 @@ ex power::expand_add(const add & a, int n, unsigned options) const term.push_back(power(b,k[l])); } - const ex & b = a.op(l); + const ex & b = a.op(m - 1); GINAC_ASSERT(!is_exactly_a(b)); GINAC_ASSERT(!is_exactly_a(b) || !is_exactly_a(ex_to(b).exponent) || @@ -901,7 +906,7 @@ ex power::expand_add(const add & a, int n, unsigned options) const term.push_back(power(b,n-k_cum[m-2])); numeric f = binomial(numeric(n),numeric(k[0])); - for (l=1; lsetflag(status_flags::dynallocated)).expand(options)); // increment k[] - l = m-2; - while ((l>=0) && ((++k[l])>upper_limit[l])) { + bool done = false; + std::size_t l = m - 2; + while ((++k[l]) > upper_limit[l]) { k[l] = 0; - --l; + if (l != 0) + --l; + else { + done = true; + break; + } } - if (l<0) break; + if (done) + break; // recalc k_cum[] and upper_limit[] k_cum[l] = (l==0 ? k[0] : k_cum[l-1]+k[l]); @@ -1007,8 +1019,13 @@ ex power::expand_mul(const mul & m, const numeric & n, unsigned options, bool fr return _ex1; } + // do not bother to rename indices if there are no any. + if ((!(options & expand_options::expand_rename_idx)) + && m.info(info_flags::has_indices)) + options |= expand_options::expand_rename_idx; // Leave it to multiplication since dummy indices have to be renamed - if (get_all_dummy_indices(m).size() > 0 && n.is_positive()) { + if ((options & expand_options::expand_rename_idx) && + (get_all_dummy_indices(m).size() > 0) && n.is_positive()) { ex result = m; exvector va = get_all_dummy_indices(m); sort(va.begin(), va.end(), ex_is_less()); @@ -1043,4 +1060,6 @@ ex power::expand_mul(const mul & m, const numeric & n, unsigned options, bool fr return result; } +GINAC_BIND_UNARCHIVER(power); + } // namespace GiNaC