From: Christian Bauer <Christian.Bauer@uni-mainz.de>
Date: Thu, 21 Nov 2002 19:16:01 +0000 (+0000)
Subject: - powers with negative exponents are printed as fractions in the LaTeX output
X-Git-Tag: release_1-0-13~19
X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=0f617ea4ea1dc6a33cae5e2ce518b26d8055c177

- powers with negative exponents are printed as fractions in the LaTeX output
- fixed some source code formatting in clifford.cpp
---

diff --git a/ginac/clifford.cpp b/ginac/clifford.cpp
index c7499db6..0a10d452 100644
--- a/ginac/clifford.cpp
+++ b/ginac/clifford.cpp
@@ -43,9 +43,9 @@ GINAC_IMPLEMENT_REGISTERED_CLASS(clifford, indexed)
 GINAC_IMPLEMENT_REGISTERED_CLASS(diracone, tensor)
 GINAC_IMPLEMENT_REGISTERED_CLASS(diracgamma, tensor)
 GINAC_IMPLEMENT_REGISTERED_CLASS(diracgamma5, tensor)
-
 GINAC_IMPLEMENT_REGISTERED_CLASS(diracgammaL, tensor)
 GINAC_IMPLEMENT_REGISTERED_CLASS(diracgammaR, tensor)
+
 //////////
 // default ctor, dtor, copy ctor, assignment operator and helpers
 //////////
@@ -65,9 +65,9 @@ DEFAULT_DESTROY(clifford)
 DEFAULT_CTORS(diracone)
 DEFAULT_CTORS(diracgamma)
 DEFAULT_CTORS(diracgamma5)
-
 DEFAULT_CTORS(diracgammaL)
 DEFAULT_CTORS(diracgammaR)
+
 //////////
 // other constructors
 //////////
@@ -120,9 +120,9 @@ DEFAULT_UNARCHIVE(clifford)
 DEFAULT_ARCHIVING(diracone)
 DEFAULT_ARCHIVING(diracgamma)
 DEFAULT_ARCHIVING(diracgamma5)
-
 DEFAULT_ARCHIVING(diracgammaL)
 DEFAULT_ARCHIVING(diracgammaR)
+
 //////////
 // functions overriding virtual functions from base classes
 //////////
diff --git a/ginac/mul.cpp b/ginac/mul.cpp
index 211855a6..f6093706 100644
--- a/ginac/mul.cpp
+++ b/ginac/mul.cpp
@@ -193,8 +193,6 @@ void mul::print(const print_context & c, unsigned level) const
 				c.s << "(";
 		}
 
-		bool first = true;
-
 		// First print the overall numeric coefficient
 		numeric coeff = ex_to<numeric>(overall_coeff);
 		if (coeff.csgn() == -1)
@@ -220,17 +218,51 @@ void mul::print(const print_context & c, unsigned level) const
 
 		// Then proceed with the remaining factors
 		epvector::const_iterator it = seq.begin(), itend = seq.end();
-		while (it != itend) {
-			if (!first) {
-				if (is_a<print_latex>(c))
-					c.s << ' ';
+		if (is_a<print_latex>(c)) {
+
+			// Separate factors into those with negative numeric exponent
+			// and all others
+			exvector neg_powers, others;
+			while (it != itend) {
+				GINAC_ASSERT(is_a<numeric>(it->coeff));
+				if (ex_to<numeric>(it->coeff).is_negative())
+					neg_powers.push_back(recombine_pair_to_ex(expair(it->rest, -(it->coeff))));
 				else
-					c.s << '*';
+					others.push_back(recombine_pair_to_ex(*it));
+				++it;
+			}
+
+			if (!neg_powers.empty()) {
+
+				// Factors with negative exponent are printed as a fraction
+				c.s << "\\frac{";
+				mul(others).eval().print(c);
+				c.s << "}{";
+				mul(neg_powers).eval().print(c);
+				c.s << "}";
+
 			} else {
-				first = false;
+
+				// All other factors are printed in the ordinary way
+				exvector::const_iterator vit = others.begin(), vitend = others.end();
+				while (vit != vitend) {
+					c.s << ' ';
+					vit->print(c, precedence());
+					++vit;
+				}
+			}
+
+		} else {
+
+			bool first = true;
+			while (it != itend) {
+				if (!first)
+					c.s << '*';
+				else
+					first = false;
+				recombine_pair_to_ex(*it).print(c, precedence());
+				++it;
 			}
-			recombine_pair_to_ex(*it).print(c, precedence());
-			++it;
 		}
 
 		if (precedence() <= level) {
diff --git a/ginac/power.cpp b/ginac/power.cpp
index 85e5bd6c..32473bd4 100644
--- a/ginac/power.cpp
+++ b/ginac/power.cpp
@@ -172,11 +172,23 @@ void power::print(const print_context & c, unsigned level) const
 
 		bool is_tex = is_a<print_latex>(c);
 
-		if (exponent.is_equal(_ex1_2)) {
+		if (is_tex && is_a<numeric>(exponent) && ex_to<numeric>(exponent).is_negative()) {
+
+			// Powers with negative numeric exponents are printed as fractions in TeX
+			c.s << "\\frac{1}{";
+			power(basis, -exponent).eval().print(c);
+			c.s << "}";
+
+		} else if (exponent.is_equal(_ex1_2)) {
+
+			// Square roots are printed in a special way
 			c.s << (is_tex ? "\\sqrt{" : "sqrt(");
 			basis.print(c);
 			c.s << (is_tex ? '}' : ')');
+
 		} else {
+
+			// Ordinary output of powers using '^' or '**'
 			if (precedence() <= level)
 				c.s << (is_tex ? "{(" : "(");
 			basis.print(c, precedence());