#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)
ex pseries::coeff(const symbol &s, int n) const
{
if (var.is_equal(s)) {
- epvector::const_iterator it = seq.begin(), itend = seq.end();
- while (it != itend) {
- int pow = ex_to_numeric(it->coeff).to_int();
- if (pow == n)
- return it->rest;
- if (pow > n)
- return _ex0();
- it++;
- }
- return _ex0();
+ if (seq.size() == 0)
+ return _ex0();
+
+ // Binary search in sequence for given power
+ numeric looking_for = numeric(n);
+ int lo = 0, hi = seq.size() - 1;
+ while (lo <= hi) {
+ int mid = (lo + hi) / 2;
+ GINAC_ASSERT(is_ex_exactly_of_type(seq[mid].coeff, numeric));
+ int cmp = ex_to_numeric(seq[mid].coeff).compare(looking_for);
+ switch (cmp) {
+ case -1:
+ lo = mid + 1;
+ break;
+ case 0:
+ return seq[mid].rest;
+ case 1:
+ hi = mid - 1;
+ break;
+ default:
+ throw(std::logic_error("pseries::coeff: compare() didn't return -1, 0 or 1"));
+ }
+ }
+ return _ex0();
} else
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)
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
}
+/** 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
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