]> www.ginac.de Git - ginac.git/blobdiff - ginac/inifcns.cpp
cleaned up some is_a<> vs. is_exactly_a<> stuff
[ginac.git] / ginac / inifcns.cpp
index 316eea6c26e621779b23ffc9d64bf15d45987e84..745223062a70a0f0ba9332942bdeece970f7a05f 100644 (file)
@@ -3,7 +3,7 @@
  *  Implementation of GiNaC's initially known functions. */
 
 /*
- *  GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2002 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
@@ -33,6 +33,7 @@
 #include "relational.h"
 #include "pseries.h"
 #include "symbol.h"
+#include "symmetry.h"
 #include "utils.h"
 
 namespace GiNaC {
@@ -43,11 +44,10 @@ namespace GiNaC {
 
 static ex abs_evalf(const ex & arg)
 {
-       BEGIN_TYPECHECK
-               TYPECHECK(arg,numeric)
-       END_TYPECHECK(abs(arg))
+       if (is_exactly_a<numeric>(arg))
+               return abs(ex_to<numeric>(arg));
        
-       return abs(ex_to<numeric>(arg));
+       return abs(arg).hold();
 }
 
 static ex abs_eval(const ex & arg)
@@ -68,11 +68,10 @@ REGISTER_FUNCTION(abs, eval_func(abs_eval).
 
 static ex csgn_evalf(const ex & arg)
 {
-       BEGIN_TYPECHECK
-               TYPECHECK(arg,numeric)
-       END_TYPECHECK(csgn(arg))
+       if (is_exactly_a<numeric>(arg))
+               return csgn(ex_to<numeric>(arg));
        
-       return csgn(ex_to<numeric>(arg));
+       return csgn(arg).hold();
 }
 
 static ex csgn_eval(const ex & arg)
@@ -80,7 +79,7 @@ static ex csgn_eval(const ex & arg)
        if (is_ex_exactly_of_type(arg, numeric))
                return csgn(ex_to<numeric>(arg));
        
-       else if (is_ex_of_type(arg, mul) &&
+       else if (is_ex_exactly_of_type(arg, mul) &&
                 is_ex_of_type(arg.op(arg.nops()-1),numeric)) {
                numeric oc = ex_to<numeric>(arg.op(arg.nops()-1));
                if (oc.is_real()) {
@@ -116,7 +115,7 @@ static ex csgn_series(const ex & arg,
                throw (std::domain_error("csgn_series(): on imaginary axis"));
        
        epvector seq;
-       seq.push_back(expair(csgn(arg_pt), _ex0()));
+       seq.push_back(expair(csgn(arg_pt), _ex0));
        return pseries(rel,seq);
 }
 
@@ -127,6 +126,8 @@ REGISTER_FUNCTION(csgn, eval_func(csgn_eval).
 
 //////////
 // Eta function: eta(x,y) == log(x*y) - log(x) - log(y).
+// This function is closely related to the unwinding number K, sometimes found
+// in modern literature: K(z) == (z-log(exp(z)))/(2*Pi*I).
 //////////
 
 static ex eta_evalf(const ex &x, const ex &y)
@@ -134,7 +135,7 @@ static ex eta_evalf(const ex &x, const ex &y)
        // It seems like we basically have to replicate the eval function here,
        // since the expression might not be fully evaluated yet.
        if (x.info(info_flags::positive) || y.info(info_flags::positive))
-               return _ex0();
+               return _ex0;
 
        if (x.info(info_flags::numeric) &&      y.info(info_flags::numeric)) {
                const numeric nx = ex_to<numeric>(x);
@@ -158,7 +159,7 @@ static ex eta_eval(const ex &x, const ex &y)
 {
        // trivial:  eta(x,c) -> 0  if c is real and positive
        if (x.info(info_flags::positive) || y.info(info_flags::positive))
-               return _ex0();
+               return _ex0;
 
        if (x.info(info_flags::numeric) &&      y.info(info_flags::numeric)) {
                // don't call eta_evalf here because it would call Pi.evalf()!
@@ -191,14 +192,15 @@ static ex eta_series(const ex & x, const ex & y,
            ((x_pt*y_pt).info(info_flags::numeric) && (x_pt*y_pt).info(info_flags::negative)))
                        throw (std::domain_error("eta_series(): on discontinuity"));
        epvector seq;
-       seq.push_back(expair(eta(x_pt,y_pt), _ex0()));
+       seq.push_back(expair(eta(x_pt,y_pt), _ex0));
        return pseries(rel,seq);
 }
 
 REGISTER_FUNCTION(eta, eval_func(eta_eval).
                        evalf_func(eta_evalf).
-                                      series_func(eta_series).
-                       latex_name("\\eta"));
+                       series_func(eta_series).
+                       latex_name("\\eta").
+                       set_symmetry(sy_symm(0, 1)));
 
 
 //////////
@@ -207,11 +209,10 @@ REGISTER_FUNCTION(eta, eval_func(eta_eval).
 
 static ex Li2_evalf(const ex & x)
 {
-       BEGIN_TYPECHECK
-               TYPECHECK(x,numeric)
-       END_TYPECHECK(Li2(x))
+       if (is_exactly_a<numeric>(x))
+               return Li2(ex_to<numeric>(x));
        
-       return Li2(ex_to<numeric>(x));  // -> numeric Li2(numeric)
+       return Li2(x).hold();
 }
 
 static ex Li2_eval(const ex & x)
@@ -219,25 +220,25 @@ static ex Li2_eval(const ex & x)
        if (x.info(info_flags::numeric)) {
                // Li2(0) -> 0
                if (x.is_zero())
-                       return _ex0();
+                       return _ex0;
                // Li2(1) -> Pi^2/6
-               if (x.is_equal(_ex1()))
-                       return power(Pi,_ex2())/_ex6();
+               if (x.is_equal(_ex1))
+                       return power(Pi,_ex2)/_ex6;
                // Li2(1/2) -> Pi^2/12 - log(2)^2/2
-               if (x.is_equal(_ex1_2()))
-                       return power(Pi,_ex2())/_ex12() + power(log(_ex2()),_ex2())*_ex_1_2();
+               if (x.is_equal(_ex1_2))
+                       return power(Pi,_ex2)/_ex12 + power(log(_ex2),_ex2)*_ex_1_2;
                // Li2(-1) -> -Pi^2/12
-               if (x.is_equal(_ex_1()))
-                       return -power(Pi,_ex2())/_ex12();
+               if (x.is_equal(_ex_1))
+                       return -power(Pi,_ex2)/_ex12;
                // Li2(I) -> -Pi^2/48+Catalan*I
                if (x.is_equal(I))
-                       return power(Pi,_ex2())/_ex_48() + Catalan*I;
+                       return power(Pi,_ex2)/_ex_48 + Catalan*I;
                // Li2(-I) -> -Pi^2/48-Catalan*I
                if (x.is_equal(-I))
-                       return power(Pi,_ex2())/_ex_48() - Catalan*I;
+                       return power(Pi,_ex2)/_ex_48 - Catalan*I;
                // Li2(float)
                if (!x.info(info_flags::crational))
-                       return Li2_evalf(x);
+                       return Li2(ex_to<numeric>(x));
        }
        
        return Li2(x).hold();
@@ -248,7 +249,7 @@ static ex Li2_deriv(const ex & x, unsigned deriv_param)
        GINAC_ASSERT(deriv_param==0);
        
        // d/dx Li2(x) -> -log(1-x)/x
-       return -log(1-x)/x;
+       return -log(_ex1-x)/x;
 }
 
 static ex Li2_series(const ex &x, const relational &rel, int order, unsigned options)
@@ -273,12 +274,12 @@ static ex Li2_series(const ex &x, const relational &rel, int order, unsigned opt
                        ex ser;
                        // manually construct the primitive expansion
                        for (int i=1; i<order; ++i)
-                               ser += pow(s,i) / pow(numeric(i), _num2());
+                               ser += pow(s,i) / pow(numeric(i), _num2);
                        // substitute the argument's series expansion
                        ser = ser.subs(s==x.series(rel, order));
                        // maybe that was terminating, so add a proper order term
                        epvector nseq;
-                       nseq.push_back(expair(Order(_ex1()), order));
+                       nseq.push_back(expair(Order(_ex1), order));
                        ser += pseries(rel, nseq);
                        // reexpanding it will collapse the series again
                        return ser.series(rel, order);
@@ -291,11 +292,11 @@ static ex Li2_series(const ex &x, const relational &rel, int order, unsigned opt
                        // obsolete!
                }
                // second special case: x==1 (branch point)
-               if (x_pt == _ex1()) {
+               if (x_pt.is_equal(_ex1)) {
                        // method:
                        // construct series manually in a dummy symbol s
                        const symbol s;
-                       ex ser = zeta(_ex2());
+                       ex ser = zeta(_ex2);
                        // manually construct the primitive expansion
                        for (int i=1; i<order; ++i)
                                ser += pow(1-s,i) * (numeric(1,i)*(I*Pi+log(s-1)) - numeric(1,i*i));
@@ -303,7 +304,7 @@ static ex Li2_series(const ex &x, const relational &rel, int order, unsigned opt
                        ser = ser.subs(s==x.series(rel, order));
                        // maybe that was terminating, so add a proper order term
                        epvector nseq;
-                       nseq.push_back(expair(Order(_ex1()), order));
+                       nseq.push_back(expair(Order(_ex1), order));
                        ser += pseries(rel, nseq);
                        // reexpanding it will collapse the series again
                        return ser.series(rel, order);
@@ -314,18 +315,18 @@ static ex Li2_series(const ex &x, const relational &rel, int order, unsigned opt
                        // method:
                        // This is the branch cut: assemble the primitive series manually
                        // and then add the corresponding complex step function.
-                       const symbol *s = static_cast<symbol *>(rel.lhs().bp);
+                       const symbol &s = ex_to<symbol>(rel.lhs());
                        const ex point = rel.rhs();
                        const symbol foo;
                        epvector seq;
                        // zeroth order term:
-                       seq.push_back(expair(Li2(x_pt), _ex0()));
+                       seq.push_back(expair(Li2(x_pt), _ex0));
                        // compute the intermediate terms:
-                       ex replarg = series(Li2(x), *s==foo, order);
+                       ex replarg = series(Li2(x), s==foo, order);
                        for (unsigned i=1; i<replarg.nops()-1; ++i)
-                               seq.push_back(expair((replarg.op(i)/power(*s-foo,i)).series(foo==point,1,options).op(0).subs(foo==*s),i));
+                               seq.push_back(expair((replarg.op(i)/power(s-foo,i)).series(foo==point,1,options).op(0).subs(foo==s),i));
                        // append an order term:
-                       seq.push_back(expair(Order(_ex1()), replarg.nops()-1));
+                       seq.push_back(expair(Order(_ex1), replarg.nops()-1));
                        return pseries(rel, seq);
                }
        }
@@ -402,14 +403,14 @@ static ex Order_eval(const ex & x)
        if (is_ex_exactly_of_type(x, numeric)) {
                // O(c) -> O(1) or 0
                if (!x.is_zero())
-                       return Order(_ex1()).hold();
+                       return Order(_ex1).hold();
                else
-                       return _ex0();
+                       return _ex0;
        } else if (is_ex_exactly_of_type(x, mul)) {
-               mul *m = static_cast<mul *>(x.bp);
+               const mul &m = ex_to<mul>(x);
                // O(c*expr) -> O(expr)
-               if (is_ex_exactly_of_type(m->op(m->nops() - 1), numeric))
-                       return Order(x / m->op(m->nops() - 1)).hold();
+               if (is_ex_exactly_of_type(m.op(m.nops() - 1), numeric))
+                       return Order(x / m.op(m.nops() - 1)).hold();
        }
        return Order(x).hold();
 }
@@ -418,9 +419,9 @@ static ex Order_series(const ex & x, const relational & r, int order, unsigned o
 {
        // Just wrap the function into a pseries object
        epvector new_seq;
-       GINAC_ASSERT(is_ex_exactly_of_type(r.lhs(),symbol));
-       const symbol *s = static_cast<symbol *>(r.lhs().bp);
-       new_seq.push_back(expair(Order(_ex1()), numeric(std::min(x.ldegree(*s), order))));
+       GINAC_ASSERT(is_a<symbol>(r.lhs()));
+       const symbol &s = ex_to<symbol>(r.lhs());
+       new_seq.push_back(expair(Order(_ex1), numeric(std::min(x.ldegree(s), order))));
        return pseries(r, new_seq);
 }
 
@@ -434,7 +435,7 @@ REGISTER_FUNCTION(Order, eval_func(Order_eval).
 // Solve linear system
 //////////
 
-ex lsolve(const ex &eqns, const ex &symbols)
+ex lsolve(const ex &eqns, const ex &symbols, unsigned options)
 {
        // solve a system of linear equations
        if (eqns.info(info_flags::relation_equal)) {
@@ -443,7 +444,7 @@ ex lsolve(const ex &eqns, const ex &symbols)
                const ex sol = lsolve(lst(eqns),lst(symbols));
                
                GINAC_ASSERT(sol.nops()==1);
-               GINAC_ASSERT(is_ex_exactly_of_type(sol.op(0),relational));
+               GINAC_ASSERT(is_exactly_a<relational>(sol.op(0)));
                
                return sol.op(0).op(1); // return rhs of first solution
        }
@@ -494,12 +495,12 @@ ex lsolve(const ex &eqns, const ex &symbols)
        
        matrix solution;
        try {
-               solution = sys.solve(vars,rhs);
+               solution = sys.solve(vars,rhs,options);
        } catch (const std::runtime_error & e) {
                // Probably singular matrix or otherwise overdetermined system:
                // It is consistent to return an empty list
                return lst();
-       }    
+       }
        GINAC_ASSERT(solution.cols()==1);
        GINAC_ASSERT(solution.rows()==symbols.nops());