* Implementation of GiNaC's products of expressions. */
/*
- * GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
+ * GiNaC Copyright (C) 1999-2002 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
while (it != itend) {
// If the first argument is a negative integer power, it gets printed as "1.0/<expr>"
- if (it == seq.begin() && ex_to<numeric>(it->coeff).is_integer() && it->coeff.compare(_num0) < 0) {
+ if (it == seq.begin() && ex_to<numeric>(it->coeff).is_integer() && it->coeff.info(info_flags::negative)) {
if (is_a<print_csrc_cl_N>(c))
c.s << "recip(";
else
}
// If the exponent is 1 or -1, it is left out
- if (it->coeff.compare(_ex1) == 0 || it->coeff.compare(_num_1) == 0)
+ if (it->coeff.is_equal(_ex1) || it->coeff.is_equal(_ex_1))
it->rest.print(c, precedence());
else {
// Outer parens around ex needed for broken gcc-2.95 parser:
// Separator is "/" for negative integer powers, "*" otherwise
++it;
if (it != itend) {
- if (ex_to<numeric>(it->coeff).is_integer() && it->coeff.compare(_num0) < 0)
+ if (ex_to<numeric>(it->coeff).is_integer() && it->coeff.info(info_flags::negative))
c.s << "/";
else
c.s << "*";
if (precedence() <= level)
c.s << ")";
+ } else if (is_a<print_python_repr>(c)) {
+ c.s << class_name() << '(';
+ op(0).print(c);
+ for (unsigned i=1; i<nops(); ++i) {
+ c.s << ',';
+ op(i).print(c);
+ }
+ c.s << ')';
} else {
if (precedence() <= level) {
(cit->coeff.is_equal(_ex1))) {
++number_of_adds;
if (is_ex_exactly_of_type(last_expanded, add)) {
+#if 1
+ // Expand a product of two sums, simple and robust version.
const add & add1 = ex_to<add>(last_expanded);
const add & add2 = ex_to<add>(cit->rest);
- int n1 = add1.nops();
- int n2 = add2.nops();
+ const int n1 = add1.nops();
+ const int n2 = add2.nops();
+ ex tmp_accu;
exvector distrseq;
- distrseq.reserve(n1*n2);
+ distrseq.reserve(n2);
for (int i1=0; i1<n1; ++i1) {
- for (int i2=0; i2<n2; ++i2) {
- distrseq.push_back(add1.op(i1) * add2.op(i2));
+ // cache the first operand (for efficiency):
+ const ex op1 = add1.op(i1);
+ for (int i2=0; i2<n2; ++i2)
+ distrseq.push_back(op1 * add2.op(i2));
+ tmp_accu += (new add(distrseq))->
+ setflag(status_flags::dynallocated);
+ distrseq.clear();
+ }
+ last_expanded = tmp_accu;
+#else
+ // Expand a product of two sums, aggressive version.
+ // Caring for the overall coefficients in separate loops can give
+ // a performance gain of up to 20%!
+ const add & add1 = ex_to<add>(last_expanded);
+ const add & add2 = ex_to<add>(cit->rest);
+ const epvector::const_iterator add1begin = add1.seq.begin();
+ const epvector::const_iterator add1end = add1.seq.end();
+ const epvector::const_iterator add2begin = add2.seq.begin();
+ 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))
+ distrseq.insert(distrseq.end(),add2begin,add2end);
+ else
+ for (epvector::const_iterator i=add2begin; i!=add2end; ++i)
+ distrseq.push_back(expair(i->rest, ex_to<numeric>(i->coeff).mul_dyn(ex_to<numeric>(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))
+ distrseq.insert(distrseq.end(),add1begin,add1end);
+ else
+ for (epvector::const_iterator i=add1begin; i!=add1end; ++i)
+ distrseq.push_back(expair(i->rest, ex_to<numeric>(i->coeff).mul_dyn(ex_to<numeric>(add2.overall_coeff))));
+ }
+ // Compute the new overall coefficient and put it together:
+ ex tmp_accu = (new add(distrseq, ex_to<numeric>(add1.overall_coeff).mul(ex_to<numeric>(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
+ // the result. Otherwise it would become waayy tooo bigg.
+ numeric oc;
+ distrseq.clear();
+ for (epvector::const_iterator i2=add2begin; i2!=add2end; ++i2) {
+ // Don't push_back expairs which might have a rest that evaluates to a numeric,
+ // since that would violate an invariant of expairseq:
+ const ex rest = (new mul(i1->rest, i2->rest))->setflag(status_flags::dynallocated);
+ if (is_ex_exactly_of_type(rest, numeric))
+ oc *= ex_to<numeric>(rest).mul_dyn(ex_to<numeric>(i1->coeff).mul_dyn(ex_to<numeric>(i2->coeff)));
+ else
+ distrseq.push_back(expair(rest, ex_to<numeric>(i1->coeff).mul_dyn(ex_to<numeric>(i2->coeff))));
}
+ tmp_accu += (new add(distrseq, oc))->setflag(status_flags::dynallocated);
}
- last_expanded = (new add(distrseq))->
- setflag(status_flags::dynallocated | (options == 0 ? status_flags::expanded : 0));
+ last_expanded = tmp_accu;
+#endif
} else {
non_adds.push_back(split_ex_to_pair(last_expanded));
last_expanded = cit->rest;
git://www.ginac.de / ginac.git / blobdiff