X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Fpower.cpp;h=309d529a69cffebb3825f96e2d1bcd13e6ff0916;hp=1aade2e6363d74e62b5178fd116d6fce5d1f67c7;hb=18c803c522d833d0723b61861841e38ed3e47c9e;hpb=b4be7b0f30fbb6178cf4ee83e1b3952e084bd8ca diff --git a/ginac/power.cpp b/ginac/power.cpp index 1aade2e6..309d529a 100644 --- a/ginac/power.cpp +++ b/ginac/power.cpp @@ -3,7 +3,7 @@ * Implementation of GiNaC's symbolic exponentiation (basis^exponent). */ /* - * GiNaC Copyright (C) 1999-2003 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 @@ -100,7 +100,7 @@ void power::print_power(const print_context & c, const char *powersymbol, const exponent.print(c, precedence()); c.s << closebrace; if (precedence() <= level) - c.s << closebrace << ')'; + c.s << ')' << closebrace; } void power::do_print_dflt(const print_dflt & c, unsigned level) const @@ -246,7 +246,14 @@ ex power::op(size_t i) const ex power::map(map_function & f) const { - return (new power(f(basis), f(exponent)))->setflag(status_flags::dynallocated); + const ex &mapped_basis = f(basis); + const ex &mapped_exponent = f(exponent); + + if (!are_ex_trivially_equal(basis, mapped_basis) + || !are_ex_trivially_equal(exponent, mapped_exponent)) + return (new power(mapped_basis, mapped_exponent))->setflag(status_flags::dynallocated); + else + return *this; } int power::degree(const ex & s) const @@ -446,7 +453,7 @@ ex power::eval(int level) const // ^(*(x,y,z),c1) -> *(x^c1,y^c1,z^c1) (c1 integer) if (num_exponent->is_integer() && is_exactly_a(ebasis)) { - return expand_mul(ex_to(ebasis), *num_exponent); + return expand_mul(ex_to(ebasis), *num_exponent, 0); } // ^(*(...,x;c1),c2) -> *(^(*(...,x;1),c2),c1^c2) (c1, c2 numeric(), c1>0) @@ -558,6 +565,16 @@ ex power::eval_ncmul(const exvector & v) const return inherited::eval_ncmul(v); } +ex power::conjugate() const +{ + ex newbasis = basis.conjugate(); + ex newexponent = exponent.conjugate(); + if (are_ex_trivially_equal(basis, newbasis) && are_ex_trivially_equal(exponent, newexponent)) { + return *this; + } + return (new power(newbasis, newexponent))->setflag(status_flags::dynallocated); +} + // protected /** Implementation of ex::diff() for a power. @@ -626,7 +643,7 @@ ex power::expand(unsigned options) const const numeric &num_exponent = ex_to(a.overall_coeff); int int_exponent = num_exponent.to_int(); if (int_exponent > 0 && is_exactly_a(expanded_basis)) - distrseq.push_back(expand_add(ex_to(expanded_basis), int_exponent)); + distrseq.push_back(expand_add(ex_to(expanded_basis), int_exponent, options)); else distrseq.push_back(power(expanded_basis, a.overall_coeff)); } else @@ -634,7 +651,7 @@ ex power::expand(unsigned options) const // Make sure that e.g. (x+y)^(1+a) -> x*(x+y)^a + y*(x+y)^a ex r = (new mul(distrseq))->setflag(status_flags::dynallocated); - return r.expand(); + return r.expand(options); } if (!is_exactly_a(expanded_exponent) || @@ -652,11 +669,11 @@ ex power::expand(unsigned options) const // (x+y)^n, n>0 if (int_exponent > 0 && is_exactly_a(expanded_basis)) - return expand_add(ex_to(expanded_basis), int_exponent); + return expand_add(ex_to(expanded_basis), int_exponent, options); // (x*y)^n -> x^n * y^n if (is_exactly_a(expanded_basis)) - return expand_mul(ex_to(expanded_basis), num_exponent); + return expand_mul(ex_to(expanded_basis), num_exponent, options, true); // cannot expand further if (are_ex_trivially_equal(basis,expanded_basis) && are_ex_trivially_equal(exponent,expanded_exponent)) @@ -677,10 +694,10 @@ ex power::expand(unsigned options) const /** expand a^n where a is an add and n is a positive integer. * @see power::expand */ -ex power::expand_add(const add & a, int n) const +ex power::expand_add(const add & a, int n, unsigned options) const { if (n==2) - return expand_add_2(a); + return expand_add_2(a, options); const size_t m = a.nops(); exvector result; @@ -713,7 +730,7 @@ ex power::expand_add(const add & a, int n) const !is_exactly_a(ex_to(b).basis) || !is_exactly_a(ex_to(b).basis)); if (is_exactly_a(b)) - term.push_back(expand_mul(ex_to(b),numeric(k[l]))); + term.push_back(expand_mul(ex_to(b), numeric(k[l]), options, true)); else term.push_back(power(b,k[l])); } @@ -727,7 +744,7 @@ ex power::expand_add(const add & a, int n) const !is_exactly_a(ex_to(b).basis) || !is_exactly_a(ex_to(b).basis)); if (is_exactly_a(b)) - term.push_back(expand_mul(ex_to(b),numeric(n-k_cum[m-2]))); + term.push_back(expand_mul(ex_to(b), numeric(n-k_cum[m-2]), options, true)); else term.push_back(power(b,n-k_cum[m-2])); @@ -737,7 +754,7 @@ ex power::expand_add(const add & a, int n) const term.push_back(f); - result.push_back((new mul(term))->setflag(status_flags::dynallocated)); + result.push_back(ex((new mul(term))->setflag(status_flags::dynallocated)).expand(options)); // increment k[] l = m-2; @@ -764,7 +781,7 @@ ex power::expand_add(const add & a, int n) const /** Special case of power::expand_add. Expands a^2 where a is an add. * @see power::expand_add */ -ex power::expand_add_2(const add & a) const +ex power::expand_add_2(const add & a, unsigned options) const { epvector sum; size_t a_nops = a.nops(); @@ -787,7 +804,7 @@ ex power::expand_add_2(const add & a) const if (c.is_equal(_ex1)) { if (is_exactly_a(r)) { - sum.push_back(expair(expand_mul(ex_to(r),_num2), + sum.push_back(expair(expand_mul(ex_to(r), _num2, options, true), _ex1)); } else { sum.push_back(expair((new power(r,_ex2))->setflag(status_flags::dynallocated), @@ -795,7 +812,7 @@ ex power::expand_add_2(const add & a) const } } else { if (is_exactly_a(r)) { - sum.push_back(a.combine_ex_with_coeff_to_pair(expand_mul(ex_to(r),_num2), + sum.push_back(a.combine_ex_with_coeff_to_pair(expand_mul(ex_to(r), _num2, options, true), ex_to(c).power_dyn(_num2))); } else { sum.push_back(a.combine_ex_with_coeff_to_pair((new power(r,_ex2))->setflag(status_flags::dynallocated), @@ -830,7 +847,7 @@ ex power::expand_add_2(const add & a) const /** Expand factors of m in m^n where m is a mul and n is and integer. * @see power::expand */ -ex power::expand_mul(const mul & m, const numeric & n) const +ex power::expand_mul(const mul & m, const numeric & n, unsigned options, bool from_expand) const { GINAC_ASSERT(n.is_integer()); @@ -839,6 +856,8 @@ ex power::expand_mul(const mul & m, const numeric & n) const epvector distrseq; distrseq.reserve(m.seq.size()); + bool need_reexpand = false; + epvector::const_iterator last = m.seq.end(); epvector::const_iterator cit = m.seq.begin(); while (cit!=last) { @@ -847,11 +866,23 @@ ex power::expand_mul(const mul & m, const numeric & n) const } else { // it is safe not to call mul::combine_pair_with_coeff_to_pair() // since n is an integer - distrseq.push_back(expair(cit->rest, ex_to(cit->coeff).mul(n))); + numeric new_coeff = ex_to(cit->coeff).mul(n); + if (from_expand && is_exactly_a(cit->rest) && new_coeff.is_pos_integer()) { + // this happens when e.g. (a+b)^(1/2) gets squared and + // the resulting product needs to be reexpanded + need_reexpand = true; + } + distrseq.push_back(expair(cit->rest, new_coeff)); } ++cit; } - return (new mul(distrseq, ex_to(m.overall_coeff).power_dyn(n)))->setflag(status_flags::dynallocated); + + const mul & result = static_cast((new mul(distrseq, ex_to(m.overall_coeff).power_dyn(n)))->setflag(status_flags::dynallocated)); + if (need_reexpand) + return ex(result).expand(options); + if (from_expand) + return result.setflag(status_flags::expanded); + return result; } } // namespace GiNaC