]> www.ginac.de Git - ginac.git/blobdiff - ginac/power.cpp
Fixed initialization order bug (references to flyweights removed!) [C.Dams].
[ginac.git] / ginac / power.cpp
index a30182ef1b7320d5088d6d3ad542a6336ac33e9c..815c59306accc437a9234707919af9e855e77fe2 100644 (file)
@@ -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) 1999-2005 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
@@ -17,7 +17,7 @@
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
 #include <vector>
 #include "indexed.h"
 #include "symbol.h"
 #include "lst.h"
-#include "print.h"
 #include "archive.h"
 #include "utils.h"
 
 namespace GiNaC {
 
-GINAC_IMPLEMENT_REGISTERED_CLASS(power, basic)
+GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(power, basic,
+  print_func<print_dflt>(&power::do_print_dflt).
+  print_func<print_latex>(&power::do_print_latex).
+  print_func<print_csrc>(&power::do_print_csrc).
+  print_func<print_python>(&power::do_print_python).
+  print_func<print_python_repr>(&power::do_print_python_repr))
 
 typedef std::vector<int> intvector;
 
@@ -85,11 +89,58 @@ DEFAULT_UNARCHIVE(power)
 
 // public
 
+void power::print_power(const print_context & c, const char *powersymbol, const char *openbrace, const char *closebrace, unsigned level) const
+{
+       // Ordinary output of powers using '^' or '**'
+       if (precedence() <= level)
+               c.s << openbrace << '(';
+       basis.print(c, precedence());
+       c.s << powersymbol;
+       c.s << openbrace;
+       exponent.print(c, precedence());
+       c.s << closebrace;
+       if (precedence() <= level)
+               c.s << ')' << closebrace;
+}
+
+void power::do_print_dflt(const print_dflt & c, unsigned level) const
+{
+       if (exponent.is_equal(_ex1_2)) {
+
+               // Square roots are printed in a special way
+               c.s << "sqrt(";
+               basis.print(c);
+               c.s << ')';
+
+       } else
+               print_power(c, "^", "", "", level);
+}
+
+void power::do_print_latex(const print_latex & c, unsigned level) const
+{
+       if (is_exactly_a<numeric>(exponent) && ex_to<numeric>(exponent).is_negative()) {
+
+               // Powers with negative numeric exponents are printed as fractions
+               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 << "\\sqrt{";
+               basis.print(c);
+               c.s << '}';
+
+       } else
+               print_power(c, "^", "{", "}", level);
+}
+
 static void print_sym_pow(const print_context & c, const symbol &x, int exp)
 {
        // Optimal output of integer powers of symbols to aid compiler CSE.
        // C.f. ISO/IEC 14882:1998, section 1.9 [intro execution], paragraph 15
-       // to learn why such a parenthisation is really necessary.
+       // to learn why such a parenthesation is really necessary.
        if (exp == 1) {
                x.print(c);
        } else if (exp == 2) {
@@ -109,96 +160,58 @@ static void print_sym_pow(const print_context & c, const symbol &x, int exp)
        }
 }
 
-void power::print(const print_context & c, unsigned level) const
+void power::do_print_csrc(const print_csrc & c, unsigned level) const
 {
-       if (is_a<print_tree>(c)) {
-
-               inherited::print(c, level);
-
-       } else if (is_a<print_csrc>(c)) {
-
-               // Integer powers of symbols are printed in a special, optimized way
-               if (exponent.info(info_flags::integer)
-                && (is_a<symbol>(basis) || is_a<constant>(basis))) {
-                       int exp = ex_to<numeric>(exponent).to_int();
-                       if (exp > 0)
-                               c.s << '(';
-                       else {
-                               exp = -exp;
-                               if (is_a<print_csrc_cl_N>(c))
-                                       c.s << "recip(";
-                               else
-                                       c.s << "1.0/(";
-                       }
-                       print_sym_pow(c, ex_to<symbol>(basis), exp);
-                       c.s << ')';
-
-               // <expr>^-1 is printed as "1.0/<expr>" or with the recip() function of CLN
-               } else if (exponent.is_equal(_ex_1)) {
+       // Integer powers of symbols are printed in a special, optimized way
+       if (exponent.info(info_flags::integer)
+        && (is_a<symbol>(basis) || is_a<constant>(basis))) {
+               int exp = ex_to<numeric>(exponent).to_int();
+               if (exp > 0)
+                       c.s << '(';
+               else {
+                       exp = -exp;
                        if (is_a<print_csrc_cl_N>(c))
                                c.s << "recip(";
                        else
                                c.s << "1.0/(";
-                       basis.print(c);
-                       c.s << ')';
-
-               // Otherwise, use the pow() or expt() (CLN) functions
-               } else {
-                       if (is_a<print_csrc_cl_N>(c))
-                               c.s << "expt(";
-                       else
-                               c.s << "pow(";
-                       basis.print(c);
-                       c.s << ',';
-                       exponent.print(c);
-                       c.s << ')';
                }
+               print_sym_pow(c, ex_to<symbol>(basis), exp);
+               c.s << ')';
 
-       } else if (is_a<print_python_repr>(c)) {
+       // <expr>^-1 is printed as "1.0/<expr>" or with the recip() function of CLN
+       } else if (exponent.is_equal(_ex_1)) {
+               if (is_a<print_csrc_cl_N>(c))
+                       c.s << "recip(";
+               else
+                       c.s << "1.0/(";
+               basis.print(c);
+               c.s << ')';
 
-               c.s << class_name() << '(';
+       // Otherwise, use the pow() or expt() (CLN) functions
+       } else {
+               if (is_a<print_csrc_cl_N>(c))
+                       c.s << "expt(";
+               else
+                       c.s << "pow(";
                basis.print(c);
                c.s << ',';
                exponent.print(c);
                c.s << ')';
+       }
+}
 
-       } else {
-
-               bool is_tex = is_a<print_latex>(c);
-
-               if (is_tex && is_exactly_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 {
+void power::do_print_python(const print_python & c, unsigned level) const
+{
+       print_power(c, "**", "", "", level);
+}
 
-                       // Ordinary output of powers using '^' or '**'
-                       if (precedence() <= level)
-                               c.s << (is_tex ? "{(" : "(");
-                       basis.print(c, precedence());
-                       if (is_a<print_python>(c))
-                               c.s << "**";
-                       else
-                               c.s << '^';
-                       if (is_tex)
-                               c.s << '{';
-                       exponent.print(c, precedence());
-                       if (is_tex)
-                               c.s << '}';
-                       if (precedence() <= level)
-                               c.s << (is_tex ? ")}" : ")");
-               }
-       }
+void power::do_print_python_repr(const print_python_repr & c, unsigned level) const
+{
+       c.s << class_name() << '(';
+       basis.print(c);
+       c.s << ',';
+       exponent.print(c);
+       c.s << ')';
 }
 
 bool power::info(unsigned inf) const
@@ -209,12 +222,14 @@ bool power::info(unsigned inf) const
                case info_flags::cinteger_polynomial:
                case info_flags::rational_polynomial:
                case info_flags::crational_polynomial:
-                       return exponent.info(info_flags::nonnegint);
+                       return exponent.info(info_flags::nonnegint) &&
+                              basis.info(inf);
                case info_flags::rational_function:
-                       return exponent.info(info_flags::integer);
+                       return exponent.info(info_flags::integer) &&
+                              basis.info(inf);
                case info_flags::algebraic:
-                       return (!exponent.info(info_flags::integer) ||
-                                       basis.info(inf));
+                       return !exponent.info(info_flags::integer) ||
+                              basis.info(inf);
        }
        return inherited::info(inf);
 }
@@ -233,7 +248,14 @@ 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
@@ -426,14 +448,14 @@ ex power::eval(int level) const
                        if (is_exactly_a<numeric>(sub_exponent)) {
                                const numeric & num_sub_exponent = ex_to<numeric>(sub_exponent);
                                GINAC_ASSERT(num_sub_exponent!=numeric(1));
-                               if (num_exponent->is_integer() || (abs(num_sub_exponent) - _num1).is_negative())
+                               if (num_exponent->is_integer() || (abs(num_sub_exponent) - (*_num1_p)).is_negative())
                                        return power(sub_basis,num_sub_exponent.mul(*num_exponent));
                        }
                }
        
                // ^(*(x,y,z),c1) -> *(x^c1,y^c1,z^c1) (c1 integer)
                if (num_exponent->is_integer() && is_exactly_a<mul>(ebasis)) {
-                       return expand_mul(ex_to<mul>(ebasis), *num_exponent);
+                       return expand_mul(ex_to<mul>(ebasis), *num_exponent, 0);
                }
        
                // ^(*(...,x;c1),c2) -> *(^(*(...,x;1),c2),c1^c2)  (c1, c2 numeric(), c1>0)
@@ -452,8 +474,8 @@ ex power::eval(int level) const
                                                return (new mul(power(*mulp,exponent),
                                                                power(num_coeff,*num_exponent)))->setflag(status_flags::dynallocated);
                                        } else {
-                                               GINAC_ASSERT(num_coeff.compare(_num0)<0);
-                                               if (!num_coeff.is_equal(_num_1)) {
+                                               GINAC_ASSERT(num_coeff.compare(*_num0_p)<0);
+                                               if (!num_coeff.is_equal(*_num_1_p)) {
                                                        mul *mulp = new mul(mulref);
                                                        mulp->overall_coeff = _ex_1;
                                                        mulp->clearflag(status_flags::evaluated);
@@ -527,14 +549,14 @@ ex power::subs(const exmap & m, unsigned options) const
         || !are_ex_trivially_equal(exponent, subsed_exponent)) 
                return power(subsed_basis, subsed_exponent).subs_one_level(m, options);
 
-       if (!(options & subs_options::subs_algebraic))
+       if (!(options & subs_options::algebraic))
                return subs_one_level(m, options);
 
        for (exmap::const_iterator it = m.begin(); it != m.end(); ++it) {
                int nummatches = std::numeric_limits<int>::max();
                lst repls;
                if (tryfactsubs(*this, it->first, nummatches, repls))
-                       return (ex_to<basic>((*this) * power(it->second.subs(ex(repls), subs_options::subs_no_pattern) / it->first.subs(ex(repls), subs_options::subs_no_pattern), nummatches))).subs_one_level(m, options);
+                       return (ex_to<basic>((*this) * power(it->second.subs(ex(repls), subs_options::no_pattern) / it->first.subs(ex(repls), subs_options::no_pattern), nummatches))).subs_one_level(m, options);
        }
 
        return subs_one_level(m, options);
@@ -545,6 +567,16 @@ 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.
@@ -582,7 +614,7 @@ unsigned power::return_type() const
 {
        return basis.return_type();
 }
-   
+
 unsigned power::return_type_tinfo() const
 {
        return basis.return_type_tinfo();
@@ -613,7 +645,7 @@ ex power::expand(unsigned options) const
                        const numeric &num_exponent = ex_to<numeric>(a.overall_coeff);
                        int int_exponent = num_exponent.to_int();
                        if (int_exponent > 0 && is_exactly_a<add>(expanded_basis))
-                               distrseq.push_back(expand_add(ex_to<add>(expanded_basis), int_exponent));
+                               distrseq.push_back(expand_add(ex_to<add>(expanded_basis), int_exponent, options));
                        else
                                distrseq.push_back(power(expanded_basis, a.overall_coeff));
                } else
@@ -621,7 +653,7 @@ ex power::expand(unsigned options) const
                
                // Make sure that e.g. (x+y)^(1+a) -> x*(x+y)^a + y*(x+y)^a
                ex r = (new mul(distrseq))->setflag(status_flags::dynallocated);
-               return r.expand();
+               return r.expand(options);
        }
        
        if (!is_exactly_a<numeric>(expanded_exponent) ||
@@ -639,11 +671,11 @@ ex power::expand(unsigned options) const
        
        // (x+y)^n, n>0
        if (int_exponent > 0 && is_exactly_a<add>(expanded_basis))
-               return expand_add(ex_to<add>(expanded_basis), int_exponent);
+               return expand_add(ex_to<add>(expanded_basis), int_exponent, options);
        
        // (x*y)^n -> x^n * y^n
        if (is_exactly_a<mul>(expanded_basis))
-               return expand_mul(ex_to<mul>(expanded_basis), num_exponent);
+               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))
@@ -664,10 +696,10 @@ ex power::expand(unsigned options) const
 
 /** expand a^n where a is an add and n is a positive integer.
  *  @see power::expand */
-ex power::expand_add(const add & a, int n) const
+ex power::expand_add(const add & a, int n, unsigned options) const
 {
        if (n==2)
-               return expand_add_2(a);
+               return expand_add_2(a, options);
 
        const size_t m = a.nops();
        exvector result;
@@ -700,7 +732,7 @@ ex power::expand_add(const add & a, int n) 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])));
+                               term.push_back(expand_mul(ex_to<mul>(b), numeric(k[l]), options, true));
                        else
                                term.push_back(power(b,k[l]));
                }
@@ -714,7 +746,7 @@ ex power::expand_add(const add & a, int n) 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])));
+                       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]));
 
@@ -724,7 +756,7 @@ ex power::expand_add(const add & a, int n) const
 
                term.push_back(f);
 
-               result.push_back((new mul(term))->setflag(status_flags::dynallocated));
+               result.push_back(ex((new mul(term))->setflag(status_flags::dynallocated)).expand(options));
 
                // increment k[]
                l = m-2;
@@ -751,7 +783,7 @@ ex power::expand_add(const add & a, int n) const
 
 /** Special case of power::expand_add. Expands a^2 where a is an add.
  *  @see power::expand_add */
-ex power::expand_add_2(const add & a) const
+ex power::expand_add_2(const add & a, unsigned options) const
 {
        epvector sum;
        size_t a_nops = a.nops();
@@ -774,7 +806,7 @@ ex power::expand_add_2(const add & a) const
                
                if (c.is_equal(_ex1)) {
                        if (is_exactly_a<mul>(r)) {
-                               sum.push_back(expair(expand_mul(ex_to<mul>(r),_num2),
+                               sum.push_back(expair(expand_mul(ex_to<mul>(r), *_num2_p, options, true),
                                                     _ex1));
                        } else {
                                sum.push_back(expair((new power(r,_ex2))->setflag(status_flags::dynallocated),
@@ -782,11 +814,11 @@ ex power::expand_add_2(const add & a) 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),
-                                                    ex_to<numeric>(c).power_dyn(_num2)));
+                               sum.push_back(a.combine_ex_with_coeff_to_pair(expand_mul(ex_to<mul>(r), *_num2_p, options, true),
+                                                    ex_to<numeric>(c).power_dyn(*_num2_p)));
                        } else {
                                sum.push_back(a.combine_ex_with_coeff_to_pair((new power(r,_ex2))->setflag(status_flags::dynallocated),
-                                                    ex_to<numeric>(c).power_dyn(_num2)));
+                                                    ex_to<numeric>(c).power_dyn(*_num2_p)));
                        }
                }
 
@@ -794,7 +826,7 @@ ex power::expand_add_2(const add & a) const
                        const ex & r1 = cit1->rest;
                        const ex & c1 = cit1->coeff;
                        sum.push_back(a.combine_ex_with_coeff_to_pair((new mul(r,r1))->setflag(status_flags::dynallocated),
-                                                                     _num2.mul(ex_to<numeric>(c)).mul_dyn(ex_to<numeric>(c1))));
+                                                                     _num2_p->mul(ex_to<numeric>(c)).mul_dyn(ex_to<numeric>(c1))));
                }
        }
        
@@ -804,10 +836,10 @@ ex power::expand_add_2(const add & a) const
        if (!a.overall_coeff.is_zero()) {
                epvector::const_iterator i = a.seq.begin(), end = a.seq.end();
                while (i != end) {
-                       sum.push_back(a.combine_pair_with_coeff_to_pair(*i, ex_to<numeric>(a.overall_coeff).mul_dyn(_num2)));
+                       sum.push_back(a.combine_pair_with_coeff_to_pair(*i, ex_to<numeric>(a.overall_coeff).mul_dyn(*_num2_p)));
                        ++i;
                }
-               sum.push_back(expair(ex_to<numeric>(a.overall_coeff).power_dyn(_num2),_ex1));
+               sum.push_back(expair(ex_to<numeric>(a.overall_coeff).power_dyn(*_num2_p),_ex1));
        }
        
        GINAC_ASSERT(sum.size()==(a_nops*(a_nops+1))/2);
@@ -817,15 +849,26 @@ ex power::expand_add_2(const add & a) 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) const
+ex power::expand_mul(const mul & m, const numeric & n, unsigned options, bool from_expand) const
 {
        GINAC_ASSERT(n.is_integer());
 
-       if (n.is_zero())
+       if (n.is_zero()) {
                return _ex1;
+       }
+
+       // Leave it to multiplication since dummy indices have to be renamed
+       if (get_all_dummy_indices(m).size() > 0) {
+               ex result = m;
+               for (int i=1; i < n.to_int(); i++)
+                       result *= rename_dummy_indices_uniquely(m,m);
+               return result;
+       }
 
        epvector distrseq;
        distrseq.reserve(m.seq.size());
+       bool need_reexpand = false;
+
        epvector::const_iterator last = m.seq.end();
        epvector::const_iterator cit = m.seq.begin();
        while (cit!=last) {
@@ -834,11 +877,23 @@ ex power::expand_mul(const mul & m, const numeric & n) const
                } else {
                        // it is safe not to call mul::combine_pair_with_coeff_to_pair()
                        // since n is an integer
-                       distrseq.push_back(expair(cit->rest, ex_to<numeric>(cit->coeff).mul(n)));
+                       numeric new_coeff = ex_to<numeric>(cit->coeff).mul(n);
+                       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;
+                       }
+                       distrseq.push_back(expair(cit->rest, new_coeff));
                }
                ++cit;
        }
-       return (new mul(distrseq, ex_to<numeric>(m.overall_coeff).power_dyn(n)))->setflag(status_flags::dynallocated);
+
+       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);
+       if (from_expand)
+               return result.setflag(status_flags::expanded);
+       return result;
 }
 
 } // namespace GiNaC