- minor fix in error log.

[ginac.git] / ginac / pseries.cpp

diff --git a/ginac/pseries.cpp b/ginac/pseries.cpp
index 0fae94bc7360f348879ef3caff8be1e8f0c7eb10..b348fd313046c8aad838655672514116fd0446b7 100644 (file)
--- a/ginac/pseries.cpp
+++ b/ginac/pseries.cpp
@@ -208,7 +208,7 @@ void pseries::print(const print_context & c, unsigned level) const
 
 int pseries::compare_same_type(const basic & other) const
 {
-       GINAC_ASSERT(is_of_type(other, pseries));
+       GINAC_ASSERT(is_a<pseries>(other));
        const pseries &o = static_cast<const pseries &>(other);
        
        // first compare the lengths of the series...
@@ -489,7 +489,7 @@ bool pseries::is_terminating(void) const
 ex basic::series(const relational & r, int order, unsigned options) const
 {
        epvector seq;
-       numeric fac(1);
+       numeric fac = 1;
        ex deriv = *this;
        ex coeff = deriv.subs(r);
        const symbol &s = ex_to<symbol>(r.lhs());
@@ -499,21 +499,23 @@ ex basic::series(const relational & r, int order, unsigned options) const
        
        int n;
        for (n=1; n<order; ++n) {
-               fac = fac.mul(numeric(n));
+               fac = fac.mul(n);
+               // We need to test for zero in order to see if the series terminates.
+               // The problem is that there is no such thing as a perfect test for
+               // zero.  Expanding the term occasionally helps a little...
                deriv = deriv.diff(s).expand();
-               if (deriv.is_zero()) {
-                       // Series terminates
+               if (deriv.is_zero())  // Series terminates
                        return pseries(r, seq);
-               }
+
                coeff = deriv.subs(r);
                if (!coeff.is_zero())
-                       seq.push_back(expair(fac.inverse() * coeff, numeric(n)));
+                       seq.push_back(expair(fac.inverse() * coeff, n));
        }
        
        // Higher-order terms, if present
        deriv = deriv.diff(s);
        if (!deriv.expand().is_zero())
-               seq.push_back(expair(Order(_ex1()), numeric(n)));
+               seq.push_back(expair(Order(_ex1()), n));
        return pseries(r, seq);
 }