]> www.ginac.de Git - ginac.git/blobdiff - ginac/inifcns_trans.cpp
Fixed a bug in atan2. It gave a division by zero error for calls like
[ginac.git] / ginac / inifcns_trans.cpp
index 364ec55e2bfce859fab2e1ade21eadb3346205e3..3f161d218c068e2a4d016fce5d5cfcb2d32f789e 100644 (file)
@@ -4,7 +4,7 @@
  *  functions. */
 
 /*
- *  GiNaC Copyright (C) 1999-2005 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2010 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
@@ -21,9 +21,6 @@
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-#include <vector>
-#include <stdexcept>
-
 #include "inifcns.h"
 #include "ex.h"
 #include "constant.h"
@@ -35,6 +32,9 @@
 #include "pseries.h"
 #include "utils.h"
 
+#include <stdexcept>
+#include <vector>
+
 namespace GiNaC {
 
 //////////
@@ -89,9 +89,21 @@ static ex exp_deriv(const ex & x, unsigned deriv_param)
        return exp(x);
 }
 
+static ex exp_real_part(const ex & x)
+{
+       return exp(GiNaC::real_part(x))*cos(GiNaC::imag_part(x));
+}
+
+static ex exp_imag_part(const ex & x)
+{
+       return exp(GiNaC::real_part(x))*sin(GiNaC::imag_part(x));
+}
+
 REGISTER_FUNCTION(exp, eval_func(exp_eval).
                        evalf_func(exp_evalf).
                        derivative_func(exp_deriv).
+                       real_part_func(exp_real_part).
+                       imag_part_func(exp_imag_part).
                        latex_name("\\exp"));
 
 //////////
@@ -232,10 +244,26 @@ static ex log_series(const ex &arg,
        throw do_taylor();  // caught by function::series()
 }
 
+static ex log_real_part(const ex & x)
+{
+       if (x.info(info_flags::nonnegative))
+               return log(x).hold();
+       return log(abs(x));
+}
+
+static ex log_imag_part(const ex & x)
+{
+       if (x.info(info_flags::nonnegative))
+               return 0;
+       return atan2(GiNaC::imag_part(x), GiNaC::real_part(x));
+}
+
 REGISTER_FUNCTION(log, eval_func(log_eval).
                        evalf_func(log_evalf).
                        derivative_func(log_deriv).
                        series_func(log_series).
+                       real_part_func(log_real_part).
+                       imag_part_func(log_imag_part).
                        latex_name("\\ln"));
 
 //////////
@@ -321,9 +349,21 @@ static ex sin_deriv(const ex & x, unsigned deriv_param)
        return cos(x);
 }
 
+static ex sin_real_part(const ex & x)
+{
+       return cosh(GiNaC::imag_part(x))*sin(GiNaC::real_part(x));
+}
+
+static ex sin_imag_part(const ex & x)
+{
+       return sinh(GiNaC::imag_part(x))*cos(GiNaC::real_part(x));
+}
+
 REGISTER_FUNCTION(sin, eval_func(sin_eval).
                        evalf_func(sin_evalf).
                        derivative_func(sin_deriv).
+                       real_part_func(sin_real_part).
+                       imag_part_func(sin_imag_part).
                        latex_name("\\sin"));
 
 //////////
@@ -409,9 +449,21 @@ static ex cos_deriv(const ex & x, unsigned deriv_param)
        return -sin(x);
 }
 
+static ex cos_real_part(const ex & x)
+{
+       return cosh(GiNaC::imag_part(x))*cos(GiNaC::real_part(x));
+}
+
+static ex cos_imag_part(const ex & x)
+{
+       return -sinh(GiNaC::imag_part(x))*sin(GiNaC::real_part(x));
+}
+
 REGISTER_FUNCTION(cos, eval_func(cos_eval).
                        evalf_func(cos_evalf).
                        derivative_func(cos_deriv).
+                       real_part_func(cos_real_part).
+                       imag_part_func(cos_imag_part).
                        latex_name("\\cos"));
 
 //////////
@@ -494,6 +546,20 @@ static ex tan_deriv(const ex & x, unsigned deriv_param)
        return (_ex1+power(tan(x),_ex2));
 }
 
+static ex tan_real_part(const ex & x)
+{
+       ex a = GiNaC::real_part(x);
+       ex b = GiNaC::imag_part(x);
+       return tan(a)/(1+power(tan(a),2)*power(tan(b),2));
+}
+
+static ex tan_imag_part(const ex & x)
+{
+       ex a = GiNaC::real_part(x);
+       ex b = GiNaC::imag_part(x);
+       return tanh(b)/(1+power(tan(a),2)*power(tan(b),2));
+}
+
 static ex tan_series(const ex &x,
                      const relational &rel,
                      int order,
@@ -514,6 +580,8 @@ REGISTER_FUNCTION(tan, eval_func(tan_eval).
                        evalf_func(tan_evalf).
                        derivative_func(tan_deriv).
                        series_func(tan_series).
+                       real_part_func(tan_real_part).
+                       imag_part_func(tan_imag_part).
                        latex_name("\\tan"));
 
 //////////
@@ -752,69 +820,67 @@ static ex atan2_evalf(const ex &y, const ex &x)
 
 static ex atan2_eval(const ex & y, const ex & x)
 {
-       if (y.info(info_flags::numeric) && x.info(info_flags::numeric)) {
+       if (y.is_zero()) {
 
-               if (y.is_zero()) {
+               // atan(0, 0) -> 0
+               if (x.is_zero())
+                       return _ex0;
 
-                       // atan(0, 0) -> 0
-                       if (x.is_zero())
-                               return _ex0;
+               // atan(0, x), x real and positive -> 0
+               if (x.info(info_flags::positive))
+                       return _ex0;
 
-                       // atan(0, x), x real and positive -> 0
-                       if (x.info(info_flags::positive))
-                               return _ex0;
+               // atan(0, x), x real and negative -> Pi
+               if (x.info(info_flags::negative))
+                       return Pi;
+       }
 
-                       // atan(0, x), x real and negative -> -Pi
-                       if (x.info(info_flags::negative))
-                               return _ex_1*Pi;
-               }
+       if (x.is_zero()) {
 
-               if (x.is_zero()) {
+               // atan(y, 0), y real and positive -> Pi/2
+               if (y.info(info_flags::positive))
+                       return _ex1_2*Pi;
 
-                       // atan(y, 0), y real and positive -> Pi/2
-                       if (y.info(info_flags::positive))
-                               return _ex1_2*Pi;
+               // atan(y, 0), y real and negative -> -Pi/2
+               if (y.info(info_flags::real) && !y.is_zero())
+                       return _ex_1_2*Pi;
+       }
 
-                       // atan(y, 0), y real and negative -> -Pi/2
-                       if (y.info(info_flags::negative))
-                               return _ex_1_2*Pi;
-               }
+       if (y.is_equal(x)) {
 
-               if (y.is_equal(x)) {
+               // atan(y, y), y real and positive -> Pi/4
+               if (y.info(info_flags::positive))
+                       return _ex1_4*Pi;
 
-                       // atan(y, y), y real and positive -> Pi/4
-                       if (y.info(info_flags::positive))
-                               return _ex1_4*Pi;
+               // atan(y, y), y real and negative -> -3/4*Pi
+               if (y.info(info_flags::negative))
+                       return numeric(-3, 4)*Pi;
+       }
 
-                       // atan(y, y), y real and negative -> -3/4*Pi
-                       if (y.info(info_flags::negative))
-                               return numeric(-3, 4)*Pi;
-               }
+       if (y.is_equal(-x)) {
 
-               if (y.is_equal(-x)) {
+               // atan(y, -y), y real and positive -> 3*Pi/4
+               if (y.info(info_flags::positive))
+                       return numeric(3, 4)*Pi;
 
-                       // atan(y, -y), y real and positive -> 3*Pi/4
-                       if (y.info(info_flags::positive))
-                               return numeric(3, 4)*Pi;
+               // atan(y, -y), y real and negative -> -Pi/4
+               if (y.info(info_flags::negative))
+                       return _ex_1_4*Pi;
+       }
 
-                       // atan(y, -y), y real and negative -> -Pi/4
-                       if (y.info(info_flags::negative))
-                               return _ex_1_4*Pi;
-               }
+       // atan(float, float) -> float
+       if (is_a<numeric>(y) && !y.info(info_flags::crational) &&
+           is_a<numeric>(x) && !x.info(info_flags::crational))
+               return atan(ex_to<numeric>(y), ex_to<numeric>(x));
 
-               // atan(float, float) -> float
-               if (!y.info(info_flags::crational) && !x.info(info_flags::crational))
-                       return atan(ex_to<numeric>(y), ex_to<numeric>(x));
-
-               // atan(real, real) -> atan(y/x) +/- Pi
-               if (y.info(info_flags::real) && x.info(info_flags::real)) {
-                       if (x.info(info_flags::positive))
-                               return atan(y/x);
-                       else if(y.info(info_flags::positive))
-                               return atan(y/x)+Pi;
-                       else
-                               return atan(y/x)-Pi;
-               }
+       // atan(real, real) -> atan(y/x) +/- Pi
+       if (y.info(info_flags::real) && x.info(info_flags::real)) {
+               if (x.info(info_flags::positive))
+                       return atan(y/x);
+               else if (y.info(info_flags::positive))
+                       return atan(y/x)+Pi;
+               else
+                       return atan(y/x)-Pi;
        }
 
        return atan2(y, x).hold();
@@ -896,9 +962,21 @@ static ex sinh_deriv(const ex & x, unsigned deriv_param)
        return cosh(x);
 }
 
+static ex sinh_real_part(const ex & x)
+{
+       return sinh(GiNaC::real_part(x))*cos(GiNaC::imag_part(x));
+}
+
+static ex sinh_imag_part(const ex & x)
+{
+       return cosh(GiNaC::real_part(x))*sin(GiNaC::imag_part(x));
+}
+
 REGISTER_FUNCTION(sinh, eval_func(sinh_eval).
                         evalf_func(sinh_evalf).
                         derivative_func(sinh_deriv).
+                        real_part_func(sinh_real_part).
+                        imag_part_func(sinh_imag_part).
                         latex_name("\\sinh"));
 
 //////////
@@ -961,9 +1039,21 @@ static ex cosh_deriv(const ex & x, unsigned deriv_param)
        return sinh(x);
 }
 
+static ex cosh_real_part(const ex & x)
+{
+       return cosh(GiNaC::real_part(x))*cos(GiNaC::imag_part(x));
+}
+
+static ex cosh_imag_part(const ex & x)
+{
+       return sinh(GiNaC::real_part(x))*sin(GiNaC::imag_part(x));
+}
+
 REGISTER_FUNCTION(cosh, eval_func(cosh_eval).
                         evalf_func(cosh_evalf).
                         derivative_func(cosh_deriv).
+                        real_part_func(cosh_real_part).
+                        imag_part_func(cosh_imag_part).
                         latex_name("\\cosh"));
 
 //////////
@@ -1042,10 +1132,26 @@ static ex tanh_series(const ex &x,
        return (sinh(x)/cosh(x)).series(rel, order, options);
 }
 
+static ex tanh_real_part(const ex & x)
+{
+       ex a = GiNaC::real_part(x);
+       ex b = GiNaC::imag_part(x);
+       return tanh(a)/(1+power(tanh(a),2)*power(tan(b),2));
+}
+
+static ex tanh_imag_part(const ex & x)
+{
+       ex a = GiNaC::real_part(x);
+       ex b = GiNaC::imag_part(x);
+       return tan(b)/(1+power(tanh(a),2)*power(tan(b),2));
+}
+
 REGISTER_FUNCTION(tanh, eval_func(tanh_eval).
                         evalf_func(tanh_evalf).
                         derivative_func(tanh_deriv).
                         series_func(tanh_series).
+                        real_part_func(tanh_real_part).
+                        imag_part_func(tanh_imag_part).
                         latex_name("\\tanh"));
 
 //////////