From: Stefan Weinzierl <stefanw@thep.physik.uni-mainz.de>
Date: Sun, 12 Jan 2014 22:19:56 +0000 (+0000)
Subject: Fix G3_evalf and G3_eval for real and negative x.
X-Git-Tag: release_1-6-3~27
X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=22dbae3e0d20ffd06e405100c295aeabfc0dfa5a;ds=sidebyside

Fix G3_evalf and G3_eval for real and negative x.

The user supplied signs of the imaginary parts are only relevant for x real
and positive. A negative sign in the case of x real and negative is irrelevant
(there is no branch cut) and led to wrong results. This is now avoided.
---

diff --git a/ginac/inifcns_nstdsums.cpp b/ginac/inifcns_nstdsums.cpp
index 043d93a8..c33a4cf8 100644
--- a/ginac/inifcns_nstdsums.cpp
+++ b/ginac/inifcns_nstdsums.cpp
@@ -1360,12 +1360,16 @@ static ex G3_evalf(const ex& x_, const ex& s_, const ex& y)
 			all_zero = false;
 		}
 		if ( ex_to<numeric>(*itx).is_real() ) {
-			if ( *its >= 0 ) {
+			if ( ex_to<numeric>(*itx).is_positive() ) {
+				if ( *its >= 0 ) {
+					sn.push_back(1);
+				}
+				else {
+					sn.push_back(-1);
+				}
+			} else {
 				sn.push_back(1);
 			}
-			else {
-				sn.push_back(-1);
-			}
 		}
 		else {
 			if ( ex_to<numeric>(*itx).imag() > 0 ) {
@@ -1424,12 +1428,16 @@ static ex G3_eval(const ex& x_, const ex& s_, const ex& y)
 			all_zero = false;
 		}
 		if ( ex_to<numeric>(*itx).is_real() ) {
-			if ( *its >= 0 ) {
+			if ( ex_to<numeric>(*itx).is_positive() ) {
+				if ( *its >= 0 ) {
+					sn.push_back(1);
+				}
+				else {
+					sn.push_back(-1);
+				}
+			} else {
 				sn.push_back(1);
 			}
-			else {
-				sn.push_back(-1);
-			}
 		}
 		else {
 			if ( ex_to<numeric>(*itx).imag() > 0 ) {