From: Christian Bauer <Christian.Bauer@uni-mainz.de>
Date: Fri, 25 May 2001 22:32:48 +0000 (+0000)
Subject: - renamed ncpower() to ncpow()
X-Git-Tag: release_0-9-0~33
X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=444d1e293d87b78f0497a55c6a4dabad010f5b62

- renamed ncpower() to ncpow()
- canonicalize_clifford() uses to_rational() now
- minor cleanups
---

diff --git a/ginac/clifford.cpp b/ginac/clifford.cpp
index d520822d..e9b50e9a 100644
--- a/ginac/clifford.cpp
+++ b/ginac/clifford.cpp
@@ -26,6 +26,8 @@
 #include "ncmul.h"
 #include "symbol.h"
 #include "numeric.h" // for I
+#include "lst.h"
+#include "relational.h"
 #include "print.h"
 #include "archive.h"
 #include "debugmsg.h"
@@ -336,6 +338,13 @@ static bool is_clifford_tinfo(unsigned ti, unsigned char rl)
 	return ti == (TINFO_clifford + rl);
 }
 
+/** Check whether a given tinfo key (as returned by return_type_tinfo()
+ *  is that of a clifford object (with an arbitrary representation label). */
+static bool is_clifford_tinfo(unsigned ti)
+{
+	return (ti & ~0xff) == TINFO_clifford;
+}
+
 ex dirac_trace(const ex & e, unsigned char rl, const ex & trONE)
 {
 	if (is_ex_of_type(e, clifford)) {
@@ -439,7 +448,7 @@ ex dirac_trace(const ex & e, unsigned char rl, const ex & trONE)
 							}
 							int sign = permutation_sign(iv);
 							result += sign * eps0123(idx1, idx2, idx3, idx4)
-							        * dirac_trace(ncmul(v), rl, trONE);
+							        * dirac_trace(ncmul(v, true), rl, trONE);
 						}
 					}
 				}
@@ -491,56 +500,54 @@ ex dirac_trace(const ex & e, unsigned char rl, const ex & trONE)
 
 ex canonicalize_clifford(const ex & e)
 {
-	if (is_ex_exactly_of_type(e, add)) {
-
-		ex sum = _ex0();
-		for (unsigned i=0; i<e.nops(); i++)
-			sum += canonicalize_clifford(e.op(i));
-		return sum;
-
-	} else if (is_ex_exactly_of_type(e, mul)) {
-
-		ex prod = _ex1();
-		for (unsigned i=0; i<e.nops(); i++)
-			prod *= canonicalize_clifford(e.op(i));
-		return prod;
-
-	} else if (is_ex_exactly_of_type(e, ncmul)) {
-
-		// Expand product, if necessary
-		ex e_expanded = e.expand();
-		if (!is_ex_of_type(e_expanded, ncmul))
-			return canonicalize_clifford(e_expanded);
-
-		if (!is_ex_of_type(e.op(0), clifford))
-			return e;
-
-		exvector v;
-		v.reserve(e.nops());
-		for (int i=0; i<e.nops(); i++)
-			v.push_back(e.op(i));
-
-		// Stupid bubble sort because we only want to swap adjacent gammas
-		exvector::iterator it = v.begin(), next_to_last = v.end() - 1;
-		if (is_ex_of_type(it->op(0), diracgamma5))
-			it++;
-		while (it != next_to_last) {
-			if (it[0].op(1).compare(it[1].op(1)) > 0) {
-				ex save0 = it[0], save1 = it[1];
-				it[0] = lorentz_g(it[0].op(1), it[1].op(1));
-				it[1] = _ex2();
-				ex sum = ncmul(v);
-				it[0] = save1;
-				it[1] = save0;
-				sum -= ncmul(v);
-				return canonicalize_clifford(sum);
+	// Scan for any ncmul objects
+	lst srl;
+	ex aux = e.to_rational(srl);
+	for (unsigned i=0; i<srl.nops(); i++) {
+
+		ex lhs = srl.op(i).lhs();
+		ex rhs = srl.op(i).rhs();
+
+		if (is_ex_exactly_of_type(rhs, ncmul)
+		 && rhs.return_type() == return_types::noncommutative
+		 && is_clifford_tinfo(rhs.return_type_tinfo())) {
+
+			// Expand product, if necessary
+			ex rhs_expanded = rhs.expand();
+			if (!is_ex_of_type(rhs_expanded, ncmul)) {
+				srl.let_op(i) = (lhs == canonicalize_clifford(rhs_expanded));
+				continue;
+
+			} else if (!is_ex_of_type(rhs.op(0), clifford))
+				continue;
+
+			exvector v;
+			v.reserve(rhs.nops());
+			for (unsigned j=0; j<rhs.nops(); j++)
+				v.push_back(rhs.op(j));
+
+			// Stupid bubble sort because we only want to swap adjacent gammas
+			exvector::iterator it = v.begin(), next_to_last = v.end() - 1;
+			if (is_ex_of_type(it->op(0), diracgamma5))
+				it++;
+			while (it != next_to_last) {
+				if (it[0].op(1).compare(it[1].op(1)) > 0) {
+					ex save0 = it[0], save1 = it[1];
+					it[0] = lorentz_g(it[0].op(1), it[1].op(1));
+					it[1] = _ex2();
+					ex sum = ncmul(v);
+					it[0] = save1;
+					it[1] = save0;
+					sum -= ncmul(v, true);
+					srl.let_op(i) = (lhs == canonicalize_clifford(sum));
+					goto next_sym;
+				}
+				it++;
 			}
-			it++;
+next_sym:	;
 		}
-		return ncmul(v);
 	}
-
-	return e;
+	return aux.subs(srl);
 }
 
 } // namespace GiNaC
diff --git a/ginac/fail.cpp b/ginac/fail.cpp
index 3818538f..4c3090fb 100644
--- a/ginac/fail.cpp
+++ b/ginac/fail.cpp
@@ -1,7 +1,7 @@
 /** @file fail.cpp
  *
- *  Implementation of class signaling failure of operation. Considered
- *  obsolete all this stuff ought to be replaced by exceptions. */
+ *  Implementation of class signaling failure of operation. Considered obsolete
+ *  (all of this is replaced by exceptions). */
 
 /*
  *  GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
diff --git a/ginac/fail.h b/ginac/fail.h
index fdab60c7..5b9c2147 100644
--- a/ginac/fail.h
+++ b/ginac/fail.h
@@ -1,7 +1,7 @@
 /** @file fail.h
  *
- *  Interface to class signaling failure of operation. Considered obsolete all
- *  this stuff ought to be replaced by exceptions. */
+ *  Interface to class signaling failure of operation. Considered obsolete
+ *  (all of this is replaced by exceptions). */
 
 /*
  *  GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
diff --git a/ginac/indexed.cpp b/ginac/indexed.cpp
index acbf7d48..9ddff040 100644
--- a/ginac/indexed.cpp
+++ b/ginac/indexed.cpp
@@ -710,7 +710,7 @@ contraction_done:
 					// Non-commutative products are always re-expanded to give
 					// simplify_ncmul() the chance to re-order and canonicalize
 					// the product
-					ex r = (non_commutative ? ex(ncmul(v)) : ex(mul(v)));
+					ex r = (non_commutative ? ex(ncmul(v, true)) : ex(mul(v)));
 					return simplify_indexed(r, free_indices, dummy_indices, sp);
 				}
 
@@ -744,7 +744,7 @@ contraction_done:
 
 	ex r;
 	if (something_changed)
-		r = non_commutative ? ex(ncmul(v)) : ex(mul(v));
+		r = non_commutative ? ex(ncmul(v, true)) : ex(mul(v));
 	else
 		r = e;
 
diff --git a/ginac/inifcns.cpp b/ginac/inifcns.cpp
index 3bf0b2f7..b55261eb 100644
--- a/ginac/inifcns.cpp
+++ b/ginac/inifcns.cpp
@@ -510,19 +510,17 @@ ex lsolve(const ex &eqns, const ex &symbols)
 }
 
 /** non-commutative power. */
-ex ncpower(const ex &basis, unsigned exponent)
+ex ncpow(const ex & basis, unsigned exponent)
 {
-	if (exponent==0) {
+	if (exponent == 0)
 		return _ex1();
-	}
 
 	exvector v;
 	v.reserve(exponent);
-	for (unsigned i=0; i<exponent; ++i) {
+	for (unsigned i=0; i<exponent; ++i)
 		v.push_back(basis);
-	}
 
-	return ncmul(v,1);
+	return ncmul(v, true);
 }
 
 /** Force inclusion of functions from initcns_gamma and inifcns_zeta
diff --git a/ginac/inifcns.h b/ginac/inifcns.h
index 73fff216..985b50ff 100644
--- a/ginac/inifcns.h
+++ b/ginac/inifcns.h
@@ -133,7 +133,8 @@ DECLARE_FUNCTION_2P(Derivative)
 
 ex lsolve(const ex &eqns, const ex &symbols);
 
-ex ncpower(const ex &basis, unsigned exponent);
+/** Power of non-commutative basis. */
+ex ncpow(const ex & basis, unsigned exponent);
 
 inline bool is_order_function(const ex & e)
 {
diff --git a/ginac/power.cpp b/ginac/power.cpp
index 15fed248..9d4b0c86 100644
--- a/ginac/power.cpp
+++ b/ginac/power.cpp
@@ -796,31 +796,6 @@ ex power::expand_mul(const mul & m, const numeric & n) const
 	return (new mul(distrseq,ex_to_numeric(m.overall_coeff).power_dyn(n)))->setflag(status_flags::dynallocated);
 }
 
-/*
-ex power::expand_commutative_3(const ex & basis, const numeric & exponent,
-                               unsigned options) const
-{
-	// obsolete
-
-	exvector distrseq;
-	epvector splitseq;
-
-	const add & addref=static_cast<const add &>(*basis.bp);
-
-	splitseq=addref.seq;
-	splitseq.pop_back();
-	ex first_operands=add(splitseq);
-	ex last_operand=addref.recombine_pair_to_ex(*(addref.seq.end()-1));
-	
-	int n=exponent.to_int();
-	for (int k=0; k<=n; k++) {
-		distrseq.push_back(binomial(n,k) * power(first_operands,numeric(k))
-		                                 * power(last_operand,numeric(n-k)));
-	}
-	return ex((new add(distrseq))->setflag(status_flags::expanded | status_flags::dynallocated)).expand(options);
-}
-*/
-
 /*
 ex power::expand_noncommutative(const ex & basis, const numeric & exponent,
 								unsigned options) const