X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Fpseries.cpp;h=4491915841b1cd746d32cde71c8effc395257d4c;hp=459b46920b59793071185925a9efd61aa502c107;hb=21ebb806befcb3873d58074454fcf8dcba138fa9;hpb=956eeb82c513a723e864edefa857133282cf692b

diff --git a/ginac/pseries.cpp b/ginac/pseries.cpp
index 459b4692..44919158 100644
--- a/ginac/pseries.cpp
+++ b/ginac/pseries.cpp
@@ -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