- atanh_series(): corrected an oops.

[ginac.git] / ginac / inifcns_trans.cpp

diff --git a/ginac/inifcns_trans.cpp b/ginac/inifcns_trans.cpp
index 87a77cb2b97e1c0a42755b09ec2184f7923b920f..924d195e7f44187eb8c6e427fa4e65166bfc46b3 100644 (file)
--- a/ginac/inifcns_trans.cpp
+++ b/ginac/inifcns_trans.cpp
@@ -144,12 +144,35 @@ static ex log_deriv(const ex & x, unsigned deriv_param)
     return power(x, _ex_1());
 }
 
-static ex log_series(const ex & x, const symbol & s, const ex & pt, int order)
+/*static ex log_series(const ex &x, const relational &rel, int order)
 {
-       if (x.subs(s == pt).is_zero()) {
+    const ex x_pt = x.subs(rel);
+    if (!x_pt.info(info_flags::negative) && !x_pt.is_zero())
+        throw do_taylor();  // caught by function::series()
+    // now we either have to care for the branch cut or the branch point:
+    if (x_pt.is_zero()) {  // branch point: return a plain log(x).
+        epvector seq;
+        seq.push_back(expair(log(x), _ex0()));
+        return pseries(rel, seq);
+    } // the branch cut:
+    const ex point = rel.rhs();
+    const symbol *s = static_cast<symbol *>(rel.lhs().bp);
+    const symbol foo;
+    // compute the formal series:
+    ex replx = series(log(x),*s==foo,order).subs(foo==point);
+    epvector seq;
+    // FIXME: this is probably off by 2 or so:
+    seq.push_back(expair(-I*csgn(x*I)*Pi,_ex0()));
+    seq.push_back(expair(Order(_ex1()),order));
+    return series(replx + pseries(rel, seq),rel,order);
+}*/
+
+static ex log_series(const ex &x, const relational &r, int order)
+{
+       if (x.subs(r).is_zero()) {
                epvector seq;
                seq.push_back(expair(log(x), _ex0()));
-               return pseries(s, pt, seq);
+               return pseries(r, seq);
        } else
                throw do_taylor();
 }
@@ -363,7 +386,7 @@ static ex tan_eval(const ex & x)
         if (z.is_equal(_num25())) // tan(5/12*Pi) -> 2+sqrt(3)
             return sign*(power(_ex3(),_ex1_2())+_ex2());
         if (z.is_equal(_num30())) // tan(Pi/2)    -> infinity
-            throw (std::domain_error("tan_eval(): infinity"));
+            throw (std::domain_error("tan_eval(): simple pole"));
     }
     
     if (is_ex_exactly_of_type(x, function)) {
@@ -395,16 +418,16 @@ static ex tan_deriv(const ex & x, unsigned deriv_param)
     return (_ex1()+power(tan(x),_ex2()));
 }
 
-static ex tan_series(const ex & x, const symbol & s, const ex & pt, int order)
+static ex tan_series(const ex &x, const relational &rel, int order)
 {
     // method:
     // Taylor series where there is no pole falls back to tan_deriv.
     // On a pole simply expand sin(x)/cos(x).
-    const ex x_pt = x.subs(s==pt);
+    const ex x_pt = x.subs(rel);
     if (!(2*x_pt/Pi).info(info_flags::odd))
         throw do_taylor();  // caught by function::series()
     // if we got here we have to care for a simple pole
-    return (sin(x)/cos(x)).series(s, pt, order+2);
+    return (sin(x)/cos(x)).series(rel, order+2);
 }
 
 REGISTER_FUNCTION(tan, eval_func(tan_eval).
@@ -752,16 +775,16 @@ static ex tanh_deriv(const ex & x, unsigned deriv_param)
     return _ex1()-power(tanh(x),_ex2());
 }
 
-static ex tanh_series(const ex & x, const symbol & s, const ex & pt, int order)
+static ex tanh_series(const ex &x, const relational &rel, int order)
 {
     // method:
     // Taylor series where there is no pole falls back to tanh_deriv.
     // On a pole simply expand sinh(x)/cosh(x).
-    const ex x_pt = x.subs(s==pt);
+    const ex x_pt = x.subs(rel);
     if (!(2*I*x_pt/Pi).info(info_flags::odd))
         throw do_taylor();  // caught by function::series()
     // if we got here we have to care for a simple pole
-    return (sinh(x)/cosh(x)).series(s, pt, order+2);
+    return (sinh(x)/cosh(x)).series(rel, order+2);
 }
 
 REGISTER_FUNCTION(tanh, eval_func(tanh_eval).
@@ -873,8 +896,8 @@ static ex atanh_eval(const ex & x)
         if (x.is_zero())
             return _ex0();
         // atanh({+|-}1) -> throw
-        if (x.is_equal(_ex1()) || x.is_equal(_ex1()))
-            throw (std::domain_error("atanh_eval(): infinity"));
+        if (x.is_equal(_ex1()) || x.is_equal(_ex_1()))
+            throw (std::domain_error("atanh_eval(): logarithmic pole"));
         // atanh(float) -> float
         if (!x.info(info_flags::crational))
             return atanh_evalf(x);