else if (level == -max_recursion_level)
throw(std::runtime_error("max recursion level reached"));
- // Normalize and expand children, chop into summands
- exvector o;
- o.reserve(seq.size()+1);
+ // Normalize and expand children, chop into summands and split each
+ // one into numerator and denominator
+ exvector nums, dens;
+ nums.reserve(seq.size()+1);
+ dens.reserve(seq.size()+1);
epvector::const_iterator it = seq.begin(), itend = seq.end();
while (it != itend) {
if (is_ex_exactly_of_type(n.op(0), add)) {
epvector::const_iterator bit = ex_to_add(n.op(0)).seq.begin(), bitend = ex_to_add(n.op(0)).seq.end();
while (bit != bitend) {
- o.push_back((new lst(recombine_pair_to_ex(*bit), n.op(1)))->setflag(status_flags::dynallocated));
+ nums.push_back(recombine_pair_to_ex(*bit));
+ dens.push_back(n.op(1));
bit++;
}
// split it into numerator and denominator
GINAC_ASSERT(ex_to_numeric(ex_to_add(n.op(0)).overall_coeff).is_rational());
numeric overall = ex_to_numeric(ex_to_add(n.op(0)).overall_coeff);
- o.push_back((new lst(overall.numer(), overall.denom() * n.op(1)))->setflag(status_flags::dynallocated));
- } else
- o.push_back(n);
+ nums.push_back(overall.numer());
+ dens.push_back(overall.denom() * n.op(1));
+ } else {
+ nums.push_back(n.op(0));
+ dens.push_back(n.op(1));
+ }
it++;
}
- o.push_back(overall_coeff.bp->normal(sym_lst, repl_lst, level-1));
+ ex n = overall_coeff.bp->normal(sym_lst, repl_lst, level-1);
+ nums.push_back(n.op(0));
+ dens.push_back(n.op(1));
+ GINAC_ASSERT(nums.size() == dens.size());
- // o is now a vector of {numerator, denominator} lists
+ // Now, nums is a vector of all numerators and dens is a vector of
+ // all denominators
- // Determine common denominator
- ex den = _ex1();
- exvector::const_iterator ait = o.begin(), aitend = o.end();
+ // Add fractions sequentially
+ exvector::const_iterator num_it = nums.begin(), num_itend = nums.end();
+ exvector::const_iterator den_it = dens.begin(), den_itend = dens.end();
//std::clog << "add::normal uses the following summands:\n";
- while (ait != aitend) {
-//std::clog << " num = " << ait->op(0) << ", den = " << ait->op(1) << endl;
- den = lcm(ait->op(1), den, false);
- ait++;
+//std::clog << " num = " << *num_it << ", den = " << *den_it << endl;
+ ex num = *num_it++, den = *den_it++;
+ while (num_it != num_itend) {
+//std::clog << " num = " << *num_it << ", den = " << *den_it << endl;
+ ex co_den1, co_den2;
+ ex g = gcd(den, *den_it, &co_den1, &co_den2, false);
+ num = (num * co_den2) + (*num_it * co_den1);
+ den *= co_den2; // this is the lcm(den, *den_it)
+ num_it++; den_it++;
}
//std::clog << " common denominator = " << den << endl;
- // Add fractions
- if (den.is_equal(_ex1())) {
-
- // Common denominator is 1, simply add all fractions
- exvector num_seq;
- for (ait=o.begin(); ait!=aitend; ait++) {
- num_seq.push_back(ait->op(0) / ait->op(1));
- }
- return (new lst((new add(num_seq))->setflag(status_flags::dynallocated), den))->setflag(status_flags::dynallocated);
-
- } else {
-
- // Perform fractional addition
- exvector num_seq;
- for (ait=o.begin(); ait!=aitend; ait++) {
- ex q;
- if (!divide(den, ait->op(1), q, false)) {
- // should not happen
- throw(std::runtime_error("invalid expression in add::normal, division failed"));
- }
- num_seq.push_back((ait->op(0) * q).expand());
- }
- ex num = (new add(num_seq))->setflag(status_flags::dynallocated);
-
- // Cancel common factors from num/den
- return frac_cancel(num, den);
- }
+ // Cancel common factors from num/den
+ return frac_cancel(num, den);
}