- collect() works better

[ginac.git] / ginac / pseries.cpp

diff --git a/ginac/pseries.cpp b/ginac/pseries.cpp
index 0f29e5f547698e08323e31525f6dc451a4ec49cc..4491915841b1cd746d32cde71c8effc395257d4c 100644 (file)
--- a/ginac/pseries.cpp
+++ b/ginac/pseries.cpp
@@ -35,9 +35,9 @@
 #include "utils.h"
 #include "debugmsg.h"
 
-#ifndef NO_GINAC_NAMESPACE
+#ifndef NO_NAMESPACE_GINAC
 namespace GiNaC {
-#endif // ndef NO_GINAC_NAMESPACE
+#endif // ndef NO_NAMESPACE_GINAC
 
 GINAC_IMPLEMENT_REGISTERED_CLASS(pseries, basic)
 
@@ -256,6 +256,14 @@ ex pseries::coeff(const symbol &s, int n) const
         return convert_to_poly().coeff(s, n);
 }
 
+ex pseries::collect(const symbol &s) const
+{
+       if (var.is_equal(s))
+               return convert_to_poly();
+       else
+               return inherited::collect(s);
+}
+
 ex pseries::eval(int level) const
 {
     if (level == 1)
@@ -298,6 +306,32 @@ ex pseries::subs(const lst & ls, const lst & lr) const
     return (new pseries(var, point.subs(ls, lr), new_seq))->setflag(status_flags::dynallocated);
 }
 
+/** Implementation of ex::diff() for a power series.  It treats the series as a
+ *  polynomial.
+ *  @see ex::diff */
+ex pseries::derivative(const symbol & s) const
+{
+    if (s == var) {
+        epvector new_seq;
+        epvector::const_iterator it = seq.begin(), itend = seq.end();
+        
+        // FIXME: coeff might depend on var
+        while (it != itend) {
+            if (is_order_function(it->rest)) {
+                new_seq.push_back(expair(it->rest, it->coeff - 1));
+            } else {
+                ex c = it->rest * it->coeff;
+                if (!c.is_zero())
+                    new_seq.push_back(expair(c, it->coeff - 1));
+            }
+            it++;
+        }
+        return pseries(var, point, new_seq);
+    } else {
+        return *this;
+    }
+}
+
 
 /*
  *  Construct ordinary polynomial out of series
@@ -663,6 +697,31 @@ ex power::series(const symbol & s, const ex & point, int order) const
 }
 
 
+/** Re-expansion of a pseries object. */
+ex pseries::series(const symbol & s, const ex & p, int order) const
+{
+       if (var.is_equal(s) && point.is_equal(p)) {
+               if (order > degree(s))
+                       return *this;
+               else {
+               epvector new_seq;
+               epvector::const_iterator it = seq.begin(), itend = seq.end();
+                       while (it != itend) {
+                               int o = ex_to_numeric(it->coeff).to_int();
+                               if (o >= order) {
+                                       new_seq.push_back(expair(Order(_ex1()), o));
+                                       break;
+                               }
+                               new_seq.push_back(*it);
+                               it++;
+                       }
+                       return pseries(var, point, new_seq);
+               }
+       } else
+               return convert_to_poly().series(s, p, order);
+}
+
+
 /** Compute the truncated series expansion of an expression.
  *  This function returns an expression containing an object of class pseries to
  *  represent the series. If the series does not terminate within the given
@@ -683,6 +742,6 @@ ex ex::series(const symbol &s, const ex &point, int order) const
 const pseries some_pseries;
 const type_info & typeid_pseries = typeid(some_pseries);
 
-#ifndef NO_GINAC_NAMESPACE
+#ifndef NO_NAMESPACE_GINAC
 } // namespace GiNaC
-#endif // ndef NO_GINAC_NAMESPACE
+#endif // ndef NO_NAMESPACE_GINAC