From: Christian Bauer <Christian.Bauer@uni-mainz.de>
Date: Tue, 27 Feb 2001 19:54:38 +0000 (+0000)
Subject: when there are multiple variables with the same maximum degree, the one with
X-Git-Tag: release_0-7-3~9
X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=867d2fdc427b4f24c7755f9f5b953988575d03d0

when there are multiple variables with the same maximum degree, the one with
the least number of terms in the leading coefficient is chosen as the main
variable in GCD computations
---

diff --git a/ginac/normal.cpp b/ginac/normal.cpp
index 0832688d..3eaf4206 100644
--- a/ginac/normal.cpp
+++ b/ginac/normal.cpp
@@ -34,7 +34,6 @@
 #include "constant.h"
 #include "expairseq.h"
 #include "fail.h"
-#include "indexed.h"
 #include "inifcns.h"
 #include "lst.h"
 #include "mul.h"
@@ -140,8 +139,17 @@ struct sym_desc {
 	/** Maximum of deg_a and deg_b (Used for sorting) */
 	int max_deg;
 
+	/** Maximum number of terms of leading coefficient of symbol in both polynomials */
+	int max_lcnops;
+
 	/** Commparison operator for sorting */
-	bool operator<(const sym_desc &x) const {return max_deg < x.max_deg;}
+	bool operator<(const sym_desc &x) const
+	{
+		if (max_deg == x.max_deg)
+			return max_lcnops < x.max_lcnops;
+		else
+			return max_deg < x.max_deg;
+	}
 };
 
 // Vector of sym_desc structures
@@ -196,7 +204,8 @@ static void get_symbol_stats(const ex &a, const ex &b, sym_desc_vec &v)
 		int deg_b = b.degree(*(it->sym));
 		it->deg_a = deg_a;
 		it->deg_b = deg_b;
-		it->max_deg = std::max(deg_a,deg_b);
+		it->max_deg = std::max(deg_a, deg_b);
+		it->max_lcnops = std::max(a.lcoeff(*(it->sym)).nops(), b.lcoeff(*(it->sym)).nops());
 		it->ldeg_a = a.ldegree(*(it->sym));
 		it->ldeg_b = b.ldegree(*(it->sym));
 		it++;
@@ -206,7 +215,7 @@ static void get_symbol_stats(const ex &a, const ex &b, sym_desc_vec &v)
 	std::clog << "Symbols:\n";
 	it = v.begin(); itend = v.end();
 	while (it != itend) {
-		std::clog << " " << *it->sym << ": deg_a=" << it->deg_a << ", deg_b=" << it->deg_b << ", ldeg_a=" << it->ldeg_a << ", ldeg_b=" << it->ldeg_b << ", max_deg=" << it->max_deg << endl;
+		std::clog << " " << *it->sym << ": deg_a=" << it->deg_a << ", deg_b=" << it->deg_b << ", ldeg_a=" << it->ldeg_a << ", ldeg_b=" << it->ldeg_b << ", max_deg=" << it->max_deg << ", max_lcnops=" << it->max_lcnops << endl;
 		std::clog << "  lcoeff_a=" << a.lcoeff(*(it->sym)) << ", lcoeff_b=" << b.lcoeff(*(it->sym)) << endl;
 		it++;
 	}