From: Jens Vollinga <vollinga@thep.physik.uni-mainz.de>
Date: Sat, 17 Apr 2004 16:07:14 +0000 (+0000)
Subject: Fixed bug in series expansion of log.
X-Git-Tag: release_1-3-0~88
X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=4405b29465293f3b6ab37745ff601f519b0256e2;hp=655bc31bf06efdea04e4142ceea5bb2cd877e8c3;ds=sidebyside

Fixed bug in series expansion of log.
---

diff --git a/ginac/inifcns_trans.cpp b/ginac/inifcns_trans.cpp
index 7df32121..872308b9 100644
--- a/ginac/inifcns_trans.cpp
+++ b/ginac/inifcns_trans.cpp
@@ -201,6 +201,22 @@ static ex log_series(const ex &arg,
 			// in this case n more (or less) terms are needed
 			// (sadly, to generate them, we have to start from the beginning)
 			const ex newarg = ex_to<pseries>((arg/coeff).series(rel, order+n, options)).shift_exponents(-n).convert_to_poly(true);
+			if (n == 0 && coeff == 1) {
+				epvector epv;
+				ex acc = (new pseries(rel, epv))->setflag(status_flags::dynallocated);
+				epv.reserve(2);
+				epv.push_back(expair(-1, _ex0));
+				epv.push_back(expair(Order(_ex1), order));
+				ex rest = pseries(rel, epv).add_series(argser);
+				for (int i = order-1; i>0; --i) {
+					epvector cterm;
+					cterm.reserve(1);
+					cterm.push_back(expair(i%2 ? _ex1/i : _ex_1/i, _ex0));
+					acc = pseries(rel, cterm).add_series(ex_to<pseries>(acc));
+					acc = (ex_to<pseries>(rest)).mul_series(ex_to<pseries>(acc));
+				}
+				return acc;
+			}
 			return pseries(rel, seq).add_series(ex_to<pseries>(log(newarg).series(rel, order, options)));
 		} else  // it was a monomial
 			return pseries(rel, seq);