* 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
print_func<print_latex>(&power::do_print_latex).
print_func<print_csrc>(&power::do_print_csrc).
print_func<print_python>(&power::do_print_python).
- print_func<print_python_repr>(&power::do_print_python_repr))
+ print_func<print_python_repr>(&power::do_print_python_repr).
+ print_func<print_csrc_cl_N>(&power::do_print_csrc_cl_N))
typedef std::vector<int> intvector;
// default constructor
//////////
-power::power() : inherited(&power::tinfo_static) { }
+power::power() { }
//////////
// other constructors
// 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);
}
n.add_ex("exponent", exponent);
}
-DEFAULT_UNARCHIVE(power)
-
//////////
// functions overriding virtual functions from base classes
//////////
}
}
+void power::do_print_csrc_cl_N(const print_csrc_cl_N& c, unsigned level) const
+{
+ if (exponent.is_equal(_ex_1)) {
+ c.s << "recip(";
+ basis.print(c);
+ c.s << ')';
+ return;
+ }
+ c.s << "expt(";
+ basis.print(c);
+ c.s << ", ";
+ exponent.print(c);
+ c.s << ')';
+}
+
void power::do_print_csrc(const print_csrc & c, unsigned level) const
{
// Integer powers of symbols are printed in a special, optimized way
c.s << '(';
else {
exp = -exp;
- if (is_a<print_csrc_cl_N>(c))
- c.s << "recip(";
- else
- c.s << "1.0/(";
+ c.s << "1.0/(";
}
print_sym_pow(c, ex_to<symbol>(basis), exp);
c.s << ')';
// <expr>^-1 is printed as "1.0/<expr>" or with the recip() function of CLN
} else if (exponent.is_equal(_ex_1)) {
- if (is_a<print_csrc_cl_N>(c))
- c.s << "recip(";
- else
- c.s << "1.0/(";
+ c.s << "1.0/(";
basis.print(c);
c.s << ')';
- // Otherwise, use the pow() or expt() (CLN) functions
+ // Otherwise, use the pow() function
} else {
- if (is_a<print_csrc_cl_N>(c))
- c.s << "expt(";
- else
- c.s << "pow(";
+ c.s << "pow(";
basis.print(c);
c.s << ',';
exponent.print(c);
basis.info(inf);
case info_flags::expanded:
return (flags & status_flags::expanded);
+ case info_flags::has_indices: {
+ if (flags & status_flags::has_indices)
+ return true;
+ else if (flags & status_flags::has_no_indices)
+ return false;
+ else if (basis.info(info_flags::has_indices)) {
+ setflag(status_flags::has_indices);
+ clearflag(status_flags::has_no_indices);
+ return true;
+ } else {
+ clearflag(status_flags::has_indices);
+ setflag(status_flags::has_no_indices);
+ return false;
+ }
+ }
}
return inherited::info(inf);
}
// (2*x + 6*y)^(-4) -> 1/16*(x + 3*y)^(-4)
if (num_exponent->is_integer() && is_exactly_a<add>(ebasis)) {
numeric icont = ebasis.integer_content();
- const numeric& lead_coeff =
- ex_to<numeric>(ex_to<add>(ebasis).seq.begin()->coeff).div_dyn(icont);
+ const numeric lead_coeff =
+ ex_to<numeric>(ex_to<add>(ebasis).seq.begin()->coeff).div(icont);
const bool canonicalizable = lead_coeff.is_integer();
const bool unit_normal = lead_coeff.is_pos_integer();
}
// 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
{
for (exmap::const_iterator it = m.begin(); it != m.end(); ++it) {
int nummatches = std::numeric_limits<int>::max();
- lst repls;
- if (tryfactsubs(*this, it->first, nummatches, repls))
- return (ex_to<basic>((*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<basic>(result)).subs_one_level(m, options);
+ }
}
return subs_one_level(m, options);
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<symbol>(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);
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<m-1; ++l) {
k[l] = 0;
while (true) {
exvector term;
term.reserve(m+1);
- for (l=0; l<m-1; ++l) {
+ for (std::size_t l = 0; l < m - 1; ++l) {
const ex & b = a.op(l);
GINAC_ASSERT(!is_exactly_a<add>(b));
GINAC_ASSERT(!is_exactly_a<power>(b) ||
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<add>(b));
GINAC_ASSERT(!is_exactly_a<power>(b) ||
!is_exactly_a<numeric>(ex_to<power>(b).exponent) ||
term.push_back(power(b,n-k_cum[m-2]));
numeric f = binomial(numeric(n),numeric(k[0]));
- for (l=1; l<m-1; ++l)
+ for (std::size_t l = 1; l < m - 1; ++l)
f *= binomial(numeric(n-k_cum[l-1]),numeric(k[l]));
term.push_back(f);
result.push_back(ex((new mul(term))->setflag(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]);
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());
return result;
}
+GINAC_BIND_UNARCHIVER(power);
+
} // namespace GiNaC
git://www.ginac.de / ginac.git / blobdiff