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[ginac.git] / ginac / power.cpp

diff --git a/ginac/power.cpp b/ginac/power.cpp
index 2cff577eabdc80e55972a2c18dd68776e08b306e..309d529a69cffebb3825f96e2d1bcd13e6ff0916 100644 (file)
--- a/ginac/power.cpp
+++ b/ginac/power.cpp
@@ -3,7 +3,7 @@
  *  Implementation of GiNaC's symbolic exponentiation (basis^exponent). */
 
 /*
- *  GiNaC Copyright (C) 1999-2003 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2004 Johannes Gutenberg University Mainz, Germany
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -246,7 +246,14 @@ ex power::op(size_t i) const
 
 ex power::map(map_function & f) const
 {
-       return (new power(f(basis), f(exponent)))->setflag(status_flags::dynallocated);
+       const ex &mapped_basis = f(basis);
+       const ex &mapped_exponent = f(exponent);
+
+       if (!are_ex_trivially_equal(basis, mapped_basis)
+        || !are_ex_trivially_equal(exponent, mapped_exponent))
+               return (new power(mapped_basis, mapped_exponent))->setflag(status_flags::dynallocated);
+       else
+               return *this;
 }
 
 int power::degree(const ex & s) const
@@ -558,6 +565,16 @@ ex power::eval_ncmul(const exvector & v) const
        return inherited::eval_ncmul(v);
 }
 
+ex power::conjugate() const
+{
+       ex newbasis = basis.conjugate();
+       ex newexponent = exponent.conjugate();
+       if (are_ex_trivially_equal(basis, newbasis) && are_ex_trivially_equal(exponent, newexponent)) {
+               return *this;
+       }
+       return (new power(newbasis, newexponent))->setflag(status_flags::dynallocated);
+}
+
 // protected
 
 /** Implementation of ex::diff() for a power.
@@ -656,7 +673,7 @@ ex power::expand(unsigned options) const
        
        // (x*y)^n -> x^n * y^n
        if (is_exactly_a<mul>(expanded_basis))
-               return expand_mul(ex_to<mul>(expanded_basis), num_exponent, options);
+               return expand_mul(ex_to<mul>(expanded_basis), num_exponent, options, true);
        
        // cannot expand further
        if (are_ex_trivially_equal(basis,expanded_basis) && are_ex_trivially_equal(exponent,expanded_exponent))
@@ -713,7 +730,7 @@ ex power::expand_add(const add & a, int n, unsigned options) const
                                     !is_exactly_a<mul>(ex_to<power>(b).basis) ||
                                     !is_exactly_a<power>(ex_to<power>(b).basis));
                        if (is_exactly_a<mul>(b))
-                               term.push_back(expand_mul(ex_to<mul>(b), numeric(k[l]), options));
+                               term.push_back(expand_mul(ex_to<mul>(b), numeric(k[l]), options, true));
                        else
                                term.push_back(power(b,k[l]));
                }
@@ -727,7 +744,7 @@ ex power::expand_add(const add & a, int n, unsigned options) const
                             !is_exactly_a<mul>(ex_to<power>(b).basis) ||
                             !is_exactly_a<power>(ex_to<power>(b).basis));
                if (is_exactly_a<mul>(b))
-                       term.push_back(expand_mul(ex_to<mul>(b), numeric(n-k_cum[m-2]), options));
+                       term.push_back(expand_mul(ex_to<mul>(b), numeric(n-k_cum[m-2]), options, true));
                else
                        term.push_back(power(b,n-k_cum[m-2]));
 
@@ -787,7 +804,7 @@ ex power::expand_add_2(const add & a, unsigned options) const
                
                if (c.is_equal(_ex1)) {
                        if (is_exactly_a<mul>(r)) {
-                               sum.push_back(expair(expand_mul(ex_to<mul>(r), _num2, options),
+                               sum.push_back(expair(expand_mul(ex_to<mul>(r), _num2, options, true),
                                                     _ex1));
                        } else {
                                sum.push_back(expair((new power(r,_ex2))->setflag(status_flags::dynallocated),
@@ -795,7 +812,7 @@ ex power::expand_add_2(const add & a, unsigned options) const
                        }
                } else {
                        if (is_exactly_a<mul>(r)) {
-                               sum.push_back(a.combine_ex_with_coeff_to_pair(expand_mul(ex_to<mul>(r), _num2, options),
+                               sum.push_back(a.combine_ex_with_coeff_to_pair(expand_mul(ex_to<mul>(r), _num2, options, true),
                                                     ex_to<numeric>(c).power_dyn(_num2)));
                        } else {
                                sum.push_back(a.combine_ex_with_coeff_to_pair((new power(r,_ex2))->setflag(status_flags::dynallocated),
@@ -830,7 +847,7 @@ ex power::expand_add_2(const add & a, unsigned options) const
 
 /** Expand factors of m in m^n where m is a mul and n is and integer.
  *  @see power::expand */
-ex power::expand_mul(const mul & m, const numeric & n, unsigned options) const
+ex power::expand_mul(const mul & m, const numeric & n, unsigned options, bool from_expand) const
 {
        GINAC_ASSERT(n.is_integer());
 
@@ -850,7 +867,7 @@ ex power::expand_mul(const mul & m, const numeric & n, unsigned options) const
                        // it is safe not to call mul::combine_pair_with_coeff_to_pair()
                        // since n is an integer
                        numeric new_coeff = ex_to<numeric>(cit->coeff).mul(n);
-                       if (is_exactly_a<add>(cit->rest) && new_coeff.is_pos_integer()) {
+                       if (from_expand && is_exactly_a<add>(cit->rest) && new_coeff.is_pos_integer()) {
                                // this happens when e.g. (a+b)^(1/2) gets squared and
                                // the resulting product needs to be reexpanded
                                need_reexpand = true;
@@ -863,8 +880,9 @@ ex power::expand_mul(const mul & m, const numeric & n, unsigned options) const
        const mul & result = static_cast<const mul &>((new mul(distrseq, ex_to<numeric>(m.overall_coeff).power_dyn(n)))->setflag(status_flags::dynallocated));
        if (need_reexpand)
                return ex(result).expand(options);
-       else
+       if (from_expand)
                return result.setflag(status_flags::expanded);
+       return result;
 }
 
 } // namespace GiNaC