From: Stefan Weinzierl <stefanw@thep.physik.uni-mainz.de>
Date: Tue, 28 Jan 2014 06:58:06 +0000 (+0200)
Subject: Li_eval(): avoid the "numeric::operator>(): complex inequality" exception.
X-Git-Tag: release_1-6-3~25
X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?a=commitdiff_plain;h=5acfced77964d811d66f83e83b8fa06d77f3edd0;p=ginac.git

Li_eval(): avoid the "numeric::operator>(): complex inequality" exception.

Basically the problem is that 1 + 0.0*I is equal to 1, but checking if
the former is positive results in the the "numeric::operator>(): complex
inequality" exception. This behavior is definitely inconsistent and should
be fixed.

As a work around teach Li_eval and convert_parameter_Li_to_H to explicitly
convert 1 + 0.0*I to 1 (and -1 + 0.0*I to -1, respectively).

[Alexei Sheplyakov: comment the code a little bit, otherwise it looks weird]
---

diff --git a/ginac/inifcns_nstdsums.cpp b/ginac/inifcns_nstdsums.cpp
index 9876075c..975a81e6 100644
--- a/ginac/inifcns_nstdsums.cpp
+++ b/ginac/inifcns_nstdsums.cpp
@@ -1577,7 +1577,17 @@ static ex Li_eval(const ex& m_, const ex& x_)
 				}
 			}
 			if (is_zeta) {
-				return zeta(m_,x_);
+				lst newx;
+				for (lst::const_iterator itx = x.begin(); itx != x.end(); ++itx) {
+					GINAC_ASSERT((*itx == _ex1) || (*itx == _ex_1));
+					// XXX: 1 + 0.0*I is considered equal to 1. However
+					// the former is a not automatically converted
+					// to a real number. Do the conversion explicitly
+					// to avoid the "numeric::operator>(): complex inequality"
+					// exception (and similar problems).
+					newx.append(*itx != _ex_1 ? _ex1 : _ex_1);
+				}
+				return zeta(m_, newx);
 			}
 			if (is_H) {
 				ex prefactor;
@@ -2494,7 +2504,12 @@ lst convert_parameter_Li_to_H(const lst& m, const lst& x, ex& pf)
 	res.append(*itm);
 	itm++;
 	while (itx != x.end()) {
-		signum *= (*itx > 0) ? 1 : -1;
+		GINAC_ASSERT((*itx == _ex1) || (*itx == _ex_1));
+		// XXX: 1 + 0.0*I is considered equal to 1. However the former
+		// is not automatically converted to a real number.
+		// Do the conversion explicitly to avoid the
+		// "numeric::operator>(): complex inequality" exception.
+		signum *= (*itx != _ex_1) ? 1 : -1;
 		pf *= signum;
 		res.append((*itm) * signum);
 		itm++;