- configure.in: bumped up version.

[ginac.git] / ginac / ncmul.cpp

diff --git a/ginac/ncmul.cpp b/ginac/ncmul.cpp
index c4cfe69cb2a93fd3b8afe03f2e571c9a1ba0e34e..eecafef4f3fb5af7661f9a667ce576778ffff0aa 100644 (file)
--- a/ginac/ncmul.cpp
+++ b/ginac/ncmul.cpp
@@ -109,7 +109,7 @@ ncmul::ncmul(exvector * vp) : inherited(vp)
 DEFAULT_ARCHIVING(ncmul)
        
 //////////
-// functions overriding virtual functions from bases classes
+// functions overriding virtual functions from base classes
 //////////
 
 // public
@@ -140,7 +140,7 @@ void ncmul::print(const print_context & c, unsigned level) const
 
 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;
@@ -149,14 +149,9 @@ ex ncmul::expand(unsigned options) const
 {
        // 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. One remark is in order here: we do not
-       // take into account the overall_coeff of the add objects. This is
-       // because in GiNaC, all terms of a sum must be of the same type, so
-       // a non-zero overall_coeff (which can only be numeric) would imply that
-       // the sum only has commutative terms. But then it would never appear
-       // as a factor of an ncmul.
+       // position and number of terms.
        intvector positions_of_adds(expanded_seq.size());
        intvector number_of_add_operands(expanded_seq.size());
 
@@ -166,14 +161,14 @@ ex ncmul::expand(unsigned options) const
        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)) {
+               if (is_exactly_a<add>(*cit)) {
                        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();
+                       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 there are no sums, we are done
@@ -190,11 +185,8 @@ ex ncmul::expand(unsigned options) const
 
        while (true) {
                exvector term = expanded_seq;
-               for (int i=0; i<number_of_adds; i++) {
-                       GINAC_ASSERT(is_ex_exactly_of_type(expanded_seq[positions_of_adds[i]], add));
-                       const add & addref = ex_to<add>(expanded_seq[positions_of_adds[i]]);
-                       term[positions_of_adds[i]] = addref.recombine_pair_to_ex(addref.seq[k[i]]);
-               }
+               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)));
 
@@ -296,18 +288,20 @@ void ncmul::append_factors(exvector & v, 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,...) ->
@@ -321,7 +315,7 @@ ex ncmul::eval(int level) const
        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)