* Implementation of GiNaC's non-commutative products of expressions. */
/*
- * GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
+ * GiNaC Copyright (C) 1999-2003 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
#include "matrix.h"
#include "print.h"
#include "archive.h"
-#include "debugmsg.h"
#include "utils.h"
namespace GiNaC {
GINAC_IMPLEMENT_REGISTERED_CLASS(ncmul, exprseq)
//////////
-// default constructor, destructor, copy constructor assignment operator and helpers
+// default ctor, dtor, copy ctor, assignment operator and helpers
//////////
ncmul::ncmul()
{
- debugmsg("ncmul default constructor",LOGLEVEL_CONSTRUCT);
tinfo_key = TINFO_ncmul;
}
ncmul::ncmul(const ex & lh, const ex & rh) : inherited(lh,rh)
{
- debugmsg("ncmul constructor from ex,ex",LOGLEVEL_CONSTRUCT);
tinfo_key = TINFO_ncmul;
}
ncmul::ncmul(const ex & f1, const ex & f2, const ex & f3) : inherited(f1,f2,f3)
{
- debugmsg("ncmul constructor from 3 ex",LOGLEVEL_CONSTRUCT);
tinfo_key = TINFO_ncmul;
}
ncmul::ncmul(const ex & f1, const ex & f2, const ex & f3,
const ex & f4) : inherited(f1,f2,f3,f4)
{
- debugmsg("ncmul constructor from 4 ex",LOGLEVEL_CONSTRUCT);
tinfo_key = TINFO_ncmul;
}
ncmul::ncmul(const ex & f1, const ex & f2, const ex & f3,
const ex & f4, const ex & f5) : inherited(f1,f2,f3,f4,f5)
{
- debugmsg("ncmul constructor from 5 ex",LOGLEVEL_CONSTRUCT);
tinfo_key = TINFO_ncmul;
}
ncmul::ncmul(const ex & f1, const ex & f2, const ex & f3,
const ex & f4, const ex & f5, const ex & f6) : inherited(f1,f2,f3,f4,f5,f6)
{
- debugmsg("ncmul constructor from 6 ex",LOGLEVEL_CONSTRUCT);
tinfo_key = TINFO_ncmul;
}
ncmul::ncmul(const exvector & v, bool discardable) : inherited(v,discardable)
{
- debugmsg("ncmul constructor from exvector,bool",LOGLEVEL_CONSTRUCT);
tinfo_key = TINFO_ncmul;
}
ncmul::ncmul(exvector * vp) : inherited(vp)
{
- debugmsg("ncmul constructor from exvector *",LOGLEVEL_CONSTRUCT);
tinfo_key = TINFO_ncmul;
}
DEFAULT_ARCHIVING(ncmul)
//////////
-// functions overriding virtual functions from bases classes
+// functions overriding virtual functions from base classes
//////////
// public
void ncmul::print(const print_context & c, unsigned level) const
{
- debugmsg("ncmul print", LOGLEVEL_PRINT);
-
- if (is_of_type(c, print_tree)) {
+ if (is_a<print_tree>(c)) {
inherited::print(c, level);
- } else if (is_of_type(c, print_csrc)) {
+ } else if (is_a<print_csrc>(c) || is_a<print_python_repr>(c)) {
- c.s << "ncmul(";
+ c.s << class_name() << "(";
exvector::const_iterator it = seq.begin(), itend = seq.end()-1;
while (it != itend) {
it->print(c, precedence());
bool ncmul::info(unsigned inf) const
{
- throw(std::logic_error("which flags have to be implemented in ncmul::info()?"));
+ return inherited::info(inf);
}
typedef std::vector<int> intvector;
ex ncmul::expand(unsigned options) const
{
- exvector sub_expanded_seq;
- intvector positions_of_adds;
- intvector number_of_add_operands;
-
- exvector expanded_seq=expandchildren(options);
-
- positions_of_adds.resize(expanded_seq.size());
- number_of_add_operands.resize(expanded_seq.size());
+ // First, expand the children
+ exvector expanded_seq = expandchildren(options);
+
+ // Now, look for all the factors that are sums and remember their
+ // position and number of terms.
+ intvector positions_of_adds(expanded_seq.size());
+ intvector number_of_add_operands(expanded_seq.size());
- int number_of_adds=0;
- int number_of_expanded_terms=1;
+ int number_of_adds = 0;
+ int number_of_expanded_terms = 1;
- unsigned current_position=0;
- exvector::const_iterator last=expanded_seq.end();
+ unsigned current_position = 0;
+ exvector::const_iterator last = expanded_seq.end();
for (exvector::const_iterator cit=expanded_seq.begin(); cit!=last; ++cit) {
- if (is_ex_exactly_of_type((*cit),add)) {
- positions_of_adds[number_of_adds]=current_position;
- const add & expanded_addref=ex_to<add>(*cit);
- number_of_add_operands[number_of_adds]=expanded_addref.seq.size();
- number_of_expanded_terms *= expanded_addref.seq.size();
+ if (is_exactly_a<add>(*cit)) {
+ positions_of_adds[number_of_adds] = current_position;
+ unsigned num_ops = cit->nops();
+ number_of_add_operands[number_of_adds] = num_ops;
+ number_of_expanded_terms *= num_ops;
number_of_adds++;
}
- current_position++;
+ ++current_position;
}
- if (number_of_adds==0) {
- return (new ncmul(expanded_seq,1))->setflag(status_flags::dynallocated ||
- status_flags::expanded);
- }
+ // If there are no sums, we are done
+ if (number_of_adds == 0)
+ return (new ncmul(expanded_seq, true))->
+ setflag(status_flags::dynallocated | (options == 0 ? status_flags::expanded : 0));
+ // Now, form all possible products of the terms of the sums with the
+ // remaining factors, and add them together
exvector distrseq;
distrseq.reserve(number_of_expanded_terms);
- intvector k;
- k.resize(number_of_adds);
-
- int l;
- for (l=0; l<number_of_adds; l++) {
- k[l]=0;
- }
+ intvector k(number_of_adds);
- while (1) {
- exvector term;
- term=expanded_seq;
- for (l=0; l<number_of_adds; l++) {
- GINAC_ASSERT(is_ex_exactly_of_type(expanded_seq[positions_of_adds[l]],add));
- const add & addref=ex_to<add>(expanded_seq[positions_of_adds[l]]);
- term[positions_of_adds[l]]=addref.recombine_pair_to_ex(addref.seq[k[l]]);
- }
- distrseq.push_back((new ncmul(term,1))->setflag(status_flags::dynallocated |
- status_flags::expanded));
+ while (true) {
+ exvector term = expanded_seq;
+ for (int i=0; i<number_of_adds; i++)
+ term[positions_of_adds[i]] = expanded_seq[positions_of_adds[i]].op(k[i]);
+ distrseq.push_back((new ncmul(term, true))->
+ setflag(status_flags::dynallocated | (options == 0 ? status_flags::expanded : 0)));
// increment k[]
- l=number_of_adds-1;
- while ((l>=0)&&((++k[l])>=number_of_add_operands[l])) {
- k[l]=0;
+ int l = number_of_adds-1;
+ while ((l>=0) && ((++k[l]) >= number_of_add_operands[l])) {
+ k[l] = 0;
l--;
}
- if (l<0) break;
+ if (l<0)
+ break;
}
- return (new add(distrseq))->setflag(status_flags::dynallocated |
- status_flags::expanded);
+ return (new add(distrseq))->
+ setflag(status_flags::dynallocated | (options == 0 ? status_flags::expanded : 0));
}
int ncmul::degree(const ex & s) const
if (coeff_found) return (new ncmul(coeffseq,1))->setflag(status_flags::dynallocated);
- return _ex0();
+ return _ex0;
}
unsigned ncmul::count_factors(const ex & e) const
typedef std::vector<unsigned> unsignedvector;
typedef std::vector<exvector> exvectorvector;
+/** Perform automatic term rewriting rules in this class. In the following
+ * x, x1, x2,... stand for a symbolic variables of type ex and c, c1, c2...
+ * stand for such expressions that contain a plain number.
+ * - ncmul(...,*(x1,x2),...,ncmul(x3,x4),...) -> ncmul(...,x1,x2,...,x3,x4,...) (associativity)
+ * - ncmul(x) -> x
+ * - ncmul() -> 1
+ * - ncmul(...,c1,...,c2,...) -> *(c1,c2,ncmul(...)) (pull out commutative elements)
+ * - ncmul(x1,y1,x2,y2) -> *(ncmul(x1,x2),ncmul(y1,y2)) (collect elements of same type)
+ * - ncmul(x1,x2,x3,...) -> x::simplify_ncmul(x1,x2,x3,...)
+ *
+ * @param level cut-off in recursive evaluation */
ex ncmul::eval(int level) const
{
- // simplifications: ncmul(...,*(x1,x2),...,ncmul(x3,x4),...) ->
- // ncmul(...,x1,x2,...,x3,x4,...) (associativity)
- // ncmul(x) -> x
- // ncmul() -> 1
- // ncmul(...,c1,...,c2,...)
- // *(c1,c2,ncmul(...)) (pull out commutative elements)
- // ncmul(x1,y1,x2,y2) -> *(ncmul(x1,x2),ncmul(y1,y2))
- // (collect elements of same type)
- // ncmul(x1,x2,x3,...) -> x::simplify_ncmul(x1,x2,x3,...)
- // the following rule would be nice, but produces a recursion,
+ // The following additional rule would be nice, but produces a recursion,
// which must be trapped by introducing a flag that the sub-ncmuls()
// are already evaluated (maybe later...)
// ncmul(x1,x2,...,X,y1,y2,...) ->
exvector evaledseq=evalchildren(level);
// ncmul(...,*(x1,x2),...,ncmul(x3,x4),...) ->
- // ncmul(...,x1,x2,...,x3,x4,...) (associativity)
+ // ncmul(...,x1,x2,...,x3,x4,...) (associativity)
unsigned factors = 0;
exvector::const_iterator cit = evaledseq.begin(), citend = evaledseq.end();
while (cit != citend)
if (assocseq.size()==1) return *(seq.begin());
// ncmul() -> 1
- if (assocseq.empty()) return _ex1();
+ if (assocseq.empty()) return _ex1;
// determine return types
unsignedvector rettypes;
ex simplified_ncmul(const exvector & v)
{
if (v.empty())
- return _ex1();
+ return _ex1;
else if (v.size() == 1)
return v[0];
else
git://www.ginac.de / ginac.git / blobdiff