]> www.ginac.de Git - ginac.git/blobdiff - ginac/inifcns_trans.cpp
Added correct series expansion for atan and atanh.
[ginac.git] / ginac / inifcns_trans.cpp
index 8705901464af978c08a8042a5e754ff5903ff921..c7dbfbe6b0508240d0666b1770c18f782568ab0c 100644 (file)
@@ -4,7 +4,7 @@
  *  functions. */
 
 /*
- *  GiNaC Copyright (C) 1999-2000 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2001 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
@@ -44,49 +44,49 @@ namespace GiNaC {
 
 static ex exp_evalf(const ex & x)
 {
-    BEGIN_TYPECHECK
-        TYPECHECK(x,numeric)
-    END_TYPECHECK(exp(x))
-    
-    return exp(ex_to_numeric(x)); // -> numeric exp(numeric)
+       BEGIN_TYPECHECK
+               TYPECHECK(x,numeric)
+       END_TYPECHECK(exp(x))
+       
+       return exp(ex_to_numeric(x)); // -> numeric exp(numeric)
 }
 
 static ex exp_eval(const ex & x)
 {
-    // exp(0) -> 1
-    if (x.is_zero()) {
-        return _ex1();
-    }
-    // exp(n*Pi*I/2) -> {+1|+I|-1|-I}
-    ex TwoExOverPiI=(_ex2()*x)/(Pi*I);
-    if (TwoExOverPiI.info(info_flags::integer)) {
-        numeric z=mod(ex_to_numeric(TwoExOverPiI),_num4());
-        if (z.is_equal(_num0()))
-            return _ex1();
-        if (z.is_equal(_num1()))
-            return ex(I);
-        if (z.is_equal(_num2()))
-            return _ex_1();
-        if (z.is_equal(_num3()))
-            return ex(-I);
-    }
-    // exp(log(x)) -> x
-    if (is_ex_the_function(x, log))
-        return x.op(0);
-    
-    // exp(float)
-    if (x.info(info_flags::numeric) && !x.info(info_flags::crational))
-        return exp_evalf(x);
-    
-    return exp(x).hold();
+       // exp(0) -> 1
+       if (x.is_zero()) {
+               return _ex1();
+       }
+       // exp(n*Pi*I/2) -> {+1|+I|-1|-I}
+       ex TwoExOverPiI=(_ex2()*x)/(Pi*I);
+       if (TwoExOverPiI.info(info_flags::integer)) {
+               numeric z=mod(ex_to_numeric(TwoExOverPiI),_num4());
+               if (z.is_equal(_num0()))
+                       return _ex1();
+               if (z.is_equal(_num1()))
+                       return ex(I);
+               if (z.is_equal(_num2()))
+                       return _ex_1();
+               if (z.is_equal(_num3()))
+                       return ex(-I);
+       }
+       // exp(log(x)) -> x
+       if (is_ex_the_function(x, log))
+               return x.op(0);
+       
+       // exp(float)
+       if (x.info(info_flags::numeric) && !x.info(info_flags::crational))
+               return exp_evalf(x);
+       
+       return exp(x).hold();
 }
 
 static ex exp_deriv(const ex & x, unsigned deriv_param)
 {
-    GINAC_ASSERT(deriv_param==0);
+       GINAC_ASSERT(deriv_param==0);
 
-    // d/dx exp(x) -> exp(x)
-    return exp(x);
+       // d/dx exp(x) -> exp(x)
+       return exp(x);
 }
 
 REGISTER_FUNCTION(exp, eval_func(exp_eval).
@@ -99,82 +99,106 @@ REGISTER_FUNCTION(exp, eval_func(exp_eval).
 
 static ex log_evalf(const ex & x)
 {
-    BEGIN_TYPECHECK
-        TYPECHECK(x,numeric)
-    END_TYPECHECK(log(x))
-    
-    return log(ex_to_numeric(x)); // -> numeric log(numeric)
+       BEGIN_TYPECHECK
+               TYPECHECK(x,numeric)
+       END_TYPECHECK(log(x))
+       
+       return log(ex_to_numeric(x)); // -> numeric log(numeric)
 }
 
 static ex log_eval(const ex & x)
 {
-    if (x.info(info_flags::numeric)) {
-        if (x.is_equal(_ex1()))  // log(1) -> 0
-            return _ex0();
-        if (x.is_equal(_ex_1())) // log(-1) -> I*Pi
-            return (I*Pi);        
-        if (x.is_equal(I))       // log(I) -> Pi*I/2
-            return (Pi*I*_num1_2());
-        if (x.is_equal(-I))      // log(-I) -> -Pi*I/2
-            return (Pi*I*_num_1_2());
-        if (x.is_equal(_ex0()))  // log(0) -> infinity
-            throw(std::domain_error("log_eval(): log(0)"));
-        // log(float)
-        if (!x.info(info_flags::crational))
-            return log_evalf(x);
-    }
-    // log(exp(t)) -> t (if -Pi < t.imag() <= Pi):
-    if (is_ex_the_function(x, exp)) {
-        ex t = x.op(0);
-        if (t.info(info_flags::numeric)) {
-            numeric nt = ex_to_numeric(t);
-            if (nt.is_real())
-                return t;
-        }
-    }
-    
-    return log(x).hold();
+       if (x.info(info_flags::numeric)) {
+               if (x.is_equal(_ex0()))  // log(0) -> infinity
+                       throw(pole_error("log_eval(): log(0)",0));
+               if (x.info(info_flags::real) && x.info(info_flags::negative))
+                       return (log(-x)+I*Pi);
+               if (x.is_equal(_ex1()))  // log(1) -> 0
+                       return _ex0();
+               if (x.is_equal(I))       // log(I) -> Pi*I/2
+                       return (Pi*I*_num1_2());
+               if (x.is_equal(-I))      // log(-I) -> -Pi*I/2
+                       return (Pi*I*_num_1_2());
+               // log(float)
+               if (!x.info(info_flags::crational))
+                       return log_evalf(x);
+       }
+       // log(exp(t)) -> t (if -Pi < t.imag() <= Pi):
+       if (is_ex_the_function(x, exp)) {
+               ex t = x.op(0);
+               if (t.info(info_flags::numeric)) {
+                       numeric nt = ex_to_numeric(t);
+                       if (nt.is_real())
+                               return t;
+               }
+       }
+       
+       return log(x).hold();
 }
 
 static ex log_deriv(const ex & x, unsigned deriv_param)
 {
-    GINAC_ASSERT(deriv_param==0);
-
-    // d/dx log(x) -> 1/x
-    return power(x, _ex_1());
-}
-
-/*static ex log_series(const ex &x, const relational &rel, int order)
-{
-    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()) {
+       GINAC_ASSERT(deriv_param==0);
+       
+       // d/dx log(x) -> 1/x
+       return power(x, _ex_1());
+}
+
+static ex log_series(const ex &arg,
+                     const relational &rel,
+                     int order,
+                     unsigned options)
+{
+       GINAC_ASSERT(is_ex_exactly_of_type(rel.lhs(),symbol));
+       ex arg_pt;
+       bool must_expand_arg = false;
+       // maybe substitution of rel into arg fails because of a pole
+       try {
+               arg_pt = arg.subs(rel);
+       } catch (pole_error) {
+               must_expand_arg = true;
+       }
+       // or we are at the branch cut anyways
+       if (arg_pt.is_zero())
+               must_expand_arg = true;
+       
+       if (must_expand_arg) {
+               // method:
+               // This is the branch point: Series expand the argument first, then
+               // trivially factorize it to isolate that part which has constant
+               // leading coefficient in this fashion:
+               //   x^n + Order(x^(n+m))  ->  x^n * (1 + Order(x^m)).
+               // Return a plain n*log(x) for the x^n part and series expand the
+               // other part.  Add them together and reexpand again in order to have
+               // one unnested pseries object.  All this also works for negative n.
+               const pseries argser = ex_to_pseries(arg.series(rel, order, options));
+               const symbol *s = static_cast<symbol *>(rel.lhs().bp);
+               const ex point = rel.rhs();
+               const int n = argser.ldegree(*s);
                epvector seq;
-               seq.push_back(expair(log(x), _ex0()));
-               return pseries(r, seq);
-       } else
-               throw do_taylor();
+               seq.push_back(expair(n*log(*s-point), _ex0()));
+               if (!argser.is_terminating() || argser.nops()!=1) {
+                       // in this case n more terms are needed
+                       ex newarg = ex_to_pseries(arg.series(rel, order+n, options)).shift_exponents(-n).convert_to_poly(true);
+                       return pseries(rel, seq).add_series(ex_to_pseries(log(newarg).series(rel, order, options)));
+               } else  // it was a monomial
+                       return pseries(rel, seq);
+       }
+       if (!(options & series_options::suppress_branchcut) &&
+                arg_pt.info(info_flags::negative)) {
+               // 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 ex point = rel.rhs();
+               const symbol foo;
+               ex replarg = series(log(arg), *s==foo, order, false).subs(foo==point);
+               epvector seq;
+               seq.push_back(expair(-I*csgn(arg*I)*Pi, _ex0()));
+               seq.push_back(expair(Order(_ex1()), order));
+               return series(replarg - I*Pi + pseries(rel, seq), rel, order);
+       }
+       throw do_taylor();  // caught by function::series()
 }
 
 REGISTER_FUNCTION(log, eval_func(log_eval).
@@ -188,75 +212,75 @@ REGISTER_FUNCTION(log, eval_func(log_eval).
 
 static ex sin_evalf(const ex & x)
 {
-    BEGIN_TYPECHECK
-       TYPECHECK(x,numeric)
-    END_TYPECHECK(sin(x))
-    
-    return sin(ex_to_numeric(x)); // -> numeric sin(numeric)
+       BEGIN_TYPECHECK
+          TYPECHECK(x,numeric)
+       END_TYPECHECK(sin(x))
+       
+       return sin(ex_to_numeric(x)); // -> numeric sin(numeric)
 }
 
 static ex sin_eval(const ex & x)
 {
-    // sin(n/d*Pi) -> { all known non-nested radicals }
-    ex SixtyExOverPi = _ex60()*x/Pi;
-    ex sign = _ex1();
-    if (SixtyExOverPi.info(info_flags::integer)) {
-        numeric z = mod(ex_to_numeric(SixtyExOverPi),_num120());
-        if (z>=_num60()) {
-            // wrap to interval [0, Pi)
-            z -= _num60();
-            sign = _ex_1();
-        }
-        if (z>_num30()) {
-            // wrap to interval [0, Pi/2)
-            z = _num60()-z;
-        }
-        if (z.is_equal(_num0()))  // sin(0)       -> 0
-            return _ex0();
-        if (z.is_equal(_num5()))  // sin(Pi/12)   -> sqrt(6)/4*(1-sqrt(3)/3)
-            return sign*_ex1_4()*power(_ex6(),_ex1_2())*(_ex1()+_ex_1_3()*power(_ex3(),_ex1_2()));
-        if (z.is_equal(_num6()))  // sin(Pi/10)   -> sqrt(5)/4-1/4
-            return sign*(_ex1_4()*power(_ex5(),_ex1_2())+_ex_1_4());
-        if (z.is_equal(_num10())) // sin(Pi/6)    -> 1/2
-            return sign*_ex1_2();
-        if (z.is_equal(_num15())) // sin(Pi/4)    -> sqrt(2)/2
-            return sign*_ex1_2()*power(_ex2(),_ex1_2());
-        if (z.is_equal(_num18())) // sin(3/10*Pi) -> sqrt(5)/4+1/4
-            return sign*(_ex1_4()*power(_ex5(),_ex1_2())+_ex1_4());
-        if (z.is_equal(_num20())) // sin(Pi/3)    -> sqrt(3)/2
-            return sign*_ex1_2()*power(_ex3(),_ex1_2());
-        if (z.is_equal(_num25())) // sin(5/12*Pi) -> sqrt(6)/4*(1+sqrt(3)/3)
-            return sign*_ex1_4()*power(_ex6(),_ex1_2())*(_ex1()+_ex1_3()*power(_ex3(),_ex1_2()));
-        if (z.is_equal(_num30())) // sin(Pi/2)    -> 1
-            return sign*_ex1();
-    }
-    
-    if (is_ex_exactly_of_type(x, function)) {
-        ex t = x.op(0);
-        // sin(asin(x)) -> x
-        if (is_ex_the_function(x, asin))
-            return t;
-        // sin(acos(x)) -> sqrt(1-x^2)
-        if (is_ex_the_function(x, acos))
-            return power(_ex1()-power(t,_ex2()),_ex1_2());
-        // sin(atan(x)) -> x*(1+x^2)^(-1/2)
-        if (is_ex_the_function(x, atan))
-            return t*power(_ex1()+power(t,_ex2()),_ex_1_2());
-    }
-    
-    // sin(float) -> float
-    if (x.info(info_flags::numeric) && !x.info(info_flags::crational))
-        return sin_evalf(x);
-    
-    return sin(x).hold();
+       // sin(n/d*Pi) -> { all known non-nested radicals }
+       ex SixtyExOverPi = _ex60()*x/Pi;
+       ex sign = _ex1();
+       if (SixtyExOverPi.info(info_flags::integer)) {
+               numeric z = mod(ex_to_numeric(SixtyExOverPi),_num120());
+               if (z>=_num60()) {
+                       // wrap to interval [0, Pi)
+                       z -= _num60();
+                       sign = _ex_1();
+               }
+               if (z>_num30()) {
+                       // wrap to interval [0, Pi/2)
+                       z = _num60()-z;
+               }
+               if (z.is_equal(_num0()))  // sin(0)       -> 0
+                       return _ex0();
+               if (z.is_equal(_num5()))  // sin(Pi/12)   -> sqrt(6)/4*(1-sqrt(3)/3)
+                       return sign*_ex1_4()*power(_ex6(),_ex1_2())*(_ex1()+_ex_1_3()*power(_ex3(),_ex1_2()));
+               if (z.is_equal(_num6()))  // sin(Pi/10)   -> sqrt(5)/4-1/4
+                       return sign*(_ex1_4()*power(_ex5(),_ex1_2())+_ex_1_4());
+               if (z.is_equal(_num10())) // sin(Pi/6)    -> 1/2
+                       return sign*_ex1_2();
+               if (z.is_equal(_num15())) // sin(Pi/4)    -> sqrt(2)/2
+                       return sign*_ex1_2()*power(_ex2(),_ex1_2());
+               if (z.is_equal(_num18())) // sin(3/10*Pi) -> sqrt(5)/4+1/4
+                       return sign*(_ex1_4()*power(_ex5(),_ex1_2())+_ex1_4());
+               if (z.is_equal(_num20())) // sin(Pi/3)    -> sqrt(3)/2
+                       return sign*_ex1_2()*power(_ex3(),_ex1_2());
+               if (z.is_equal(_num25())) // sin(5/12*Pi) -> sqrt(6)/4*(1+sqrt(3)/3)
+                       return sign*_ex1_4()*power(_ex6(),_ex1_2())*(_ex1()+_ex1_3()*power(_ex3(),_ex1_2()));
+               if (z.is_equal(_num30())) // sin(Pi/2)    -> 1
+                       return sign*_ex1();
+       }
+       
+       if (is_ex_exactly_of_type(x, function)) {
+               ex t = x.op(0);
+               // sin(asin(x)) -> x
+               if (is_ex_the_function(x, asin))
+                       return t;
+               // sin(acos(x)) -> sqrt(1-x^2)
+               if (is_ex_the_function(x, acos))
+                       return power(_ex1()-power(t,_ex2()),_ex1_2());
+               // sin(atan(x)) -> x*(1+x^2)^(-1/2)
+               if (is_ex_the_function(x, atan))
+                       return t*power(_ex1()+power(t,_ex2()),_ex_1_2());
+       }
+       
+       // sin(float) -> float
+       if (x.info(info_flags::numeric) && !x.info(info_flags::crational))
+               return sin_evalf(x);
+       
+       return sin(x).hold();
 }
 
 static ex sin_deriv(const ex & x, unsigned deriv_param)
 {
-    GINAC_ASSERT(deriv_param==0);
-    
-    // d/dx sin(x) -> cos(x)
-    return cos(x);
+       GINAC_ASSERT(deriv_param==0);
+       
+       // d/dx sin(x) -> cos(x)
+       return cos(x);
 }
 
 REGISTER_FUNCTION(sin, eval_func(sin_eval).
@@ -269,75 +293,75 @@ REGISTER_FUNCTION(sin, eval_func(sin_eval).
 
 static ex cos_evalf(const ex & x)
 {
-    BEGIN_TYPECHECK
-        TYPECHECK(x,numeric)
-    END_TYPECHECK(cos(x))
-    
-    return cos(ex_to_numeric(x)); // -> numeric cos(numeric)
+       BEGIN_TYPECHECK
+               TYPECHECK(x,numeric)
+       END_TYPECHECK(cos(x))
+       
+       return cos(ex_to_numeric(x)); // -> numeric cos(numeric)
 }
 
 static ex cos_eval(const ex & x)
 {
-    // cos(n/d*Pi) -> { all known non-nested radicals }
-    ex SixtyExOverPi = _ex60()*x/Pi;
-    ex sign = _ex1();
-    if (SixtyExOverPi.info(info_flags::integer)) {
-        numeric z = mod(ex_to_numeric(SixtyExOverPi),_num120());
-        if (z>=_num60()) {
-            // wrap to interval [0, Pi)
-            z = _num120()-z;
-        }
-        if (z>=_num30()) {
-            // wrap to interval [0, Pi/2)
-            z = _num60()-z;
-            sign = _ex_1();
-        }
-        if (z.is_equal(_num0()))  // cos(0)       -> 1
-            return sign*_ex1();
-        if (z.is_equal(_num5()))  // cos(Pi/12)   -> sqrt(6)/4*(1+sqrt(3)/3)
-            return sign*_ex1_4()*power(_ex6(),_ex1_2())*(_ex1()+_ex1_3()*power(_ex3(),_ex1_2()));
-        if (z.is_equal(_num10())) // cos(Pi/6)    -> sqrt(3)/2
-            return sign*_ex1_2()*power(_ex3(),_ex1_2());
-        if (z.is_equal(_num12())) // cos(Pi/5)    -> sqrt(5)/4+1/4
-            return sign*(_ex1_4()*power(_ex5(),_ex1_2())+_ex1_4());
-        if (z.is_equal(_num15())) // cos(Pi/4)    -> sqrt(2)/2
-            return sign*_ex1_2()*power(_ex2(),_ex1_2());
-        if (z.is_equal(_num20())) // cos(Pi/3)    -> 1/2
-            return sign*_ex1_2();
-        if (z.is_equal(_num24())) // cos(2/5*Pi)  -> sqrt(5)/4-1/4x
-            return sign*(_ex1_4()*power(_ex5(),_ex1_2())+_ex_1_4());
-        if (z.is_equal(_num25())) // cos(5/12*Pi) -> sqrt(6)/4*(1-sqrt(3)/3)
-            return sign*_ex1_4()*power(_ex6(),_ex1_2())*(_ex1()+_ex_1_3()*power(_ex3(),_ex1_2()));
-        if (z.is_equal(_num30())) // cos(Pi/2)    -> 0
-            return sign*_ex0();
-    }
-    
-    if (is_ex_exactly_of_type(x, function)) {
-        ex t = x.op(0);
-        // cos(acos(x)) -> x
-        if (is_ex_the_function(x, acos))
-            return t;
-        // cos(asin(x)) -> (1-x^2)^(1/2)
-        if (is_ex_the_function(x, asin))
-            return power(_ex1()-power(t,_ex2()),_ex1_2());
-        // cos(atan(x)) -> (1+x^2)^(-1/2)
-        if (is_ex_the_function(x, atan))
-            return power(_ex1()+power(t,_ex2()),_ex_1_2());
-    }
-    
-    // cos(float) -> float
-    if (x.info(info_flags::numeric) && !x.info(info_flags::crational))
-        return cos_evalf(x);
-    
-    return cos(x).hold();
+       // cos(n/d*Pi) -> { all known non-nested radicals }
+       ex SixtyExOverPi = _ex60()*x/Pi;
+       ex sign = _ex1();
+       if (SixtyExOverPi.info(info_flags::integer)) {
+               numeric z = mod(ex_to_numeric(SixtyExOverPi),_num120());
+               if (z>=_num60()) {
+                       // wrap to interval [0, Pi)
+                       z = _num120()-z;
+               }
+               if (z>=_num30()) {
+                       // wrap to interval [0, Pi/2)
+                       z = _num60()-z;
+                       sign = _ex_1();
+               }
+               if (z.is_equal(_num0()))  // cos(0)       -> 1
+                       return sign*_ex1();
+               if (z.is_equal(_num5()))  // cos(Pi/12)   -> sqrt(6)/4*(1+sqrt(3)/3)
+                       return sign*_ex1_4()*power(_ex6(),_ex1_2())*(_ex1()+_ex1_3()*power(_ex3(),_ex1_2()));
+               if (z.is_equal(_num10())) // cos(Pi/6)    -> sqrt(3)/2
+                       return sign*_ex1_2()*power(_ex3(),_ex1_2());
+               if (z.is_equal(_num12())) // cos(Pi/5)    -> sqrt(5)/4+1/4
+                       return sign*(_ex1_4()*power(_ex5(),_ex1_2())+_ex1_4());
+               if (z.is_equal(_num15())) // cos(Pi/4)    -> sqrt(2)/2
+                       return sign*_ex1_2()*power(_ex2(),_ex1_2());
+               if (z.is_equal(_num20())) // cos(Pi/3)    -> 1/2
+                       return sign*_ex1_2();
+               if (z.is_equal(_num24())) // cos(2/5*Pi)  -> sqrt(5)/4-1/4x
+                       return sign*(_ex1_4()*power(_ex5(),_ex1_2())+_ex_1_4());
+               if (z.is_equal(_num25())) // cos(5/12*Pi) -> sqrt(6)/4*(1-sqrt(3)/3)
+                       return sign*_ex1_4()*power(_ex6(),_ex1_2())*(_ex1()+_ex_1_3()*power(_ex3(),_ex1_2()));
+               if (z.is_equal(_num30())) // cos(Pi/2)    -> 0
+                       return sign*_ex0();
+       }
+       
+       if (is_ex_exactly_of_type(x, function)) {
+               ex t = x.op(0);
+               // cos(acos(x)) -> x
+               if (is_ex_the_function(x, acos))
+                       return t;
+               // cos(asin(x)) -> (1-x^2)^(1/2)
+               if (is_ex_the_function(x, asin))
+                       return power(_ex1()-power(t,_ex2()),_ex1_2());
+               // cos(atan(x)) -> (1+x^2)^(-1/2)
+               if (is_ex_the_function(x, atan))
+                       return power(_ex1()+power(t,_ex2()),_ex_1_2());
+       }
+       
+       // cos(float) -> float
+       if (x.info(info_flags::numeric) && !x.info(info_flags::crational))
+               return cos_evalf(x);
+       
+       return cos(x).hold();
 }
 
 static ex cos_deriv(const ex & x, unsigned deriv_param)
 {
-    GINAC_ASSERT(deriv_param==0);
+       GINAC_ASSERT(deriv_param==0);
 
-    // d/dx cos(x) -> -sin(x)
-    return _ex_1()*sin(x);
+       // d/dx cos(x) -> -sin(x)
+       return _ex_1()*sin(x);
 }
 
 REGISTER_FUNCTION(cos, eval_func(cos_eval).
@@ -350,84 +374,88 @@ REGISTER_FUNCTION(cos, eval_func(cos_eval).
 
 static ex tan_evalf(const ex & x)
 {
-    BEGIN_TYPECHECK
-       TYPECHECK(x,numeric)
-    END_TYPECHECK(tan(x)) // -> numeric tan(numeric)
-    
-    return tan(ex_to_numeric(x));
+       BEGIN_TYPECHECK
+          TYPECHECK(x,numeric)
+       END_TYPECHECK(tan(x)) // -> numeric tan(numeric)
+       
+       return tan(ex_to_numeric(x));
 }
 
 static ex tan_eval(const ex & x)
 {
-    // tan(n/d*Pi) -> { all known non-nested radicals }
-    ex SixtyExOverPi = _ex60()*x/Pi;
-    ex sign = _ex1();
-    if (SixtyExOverPi.info(info_flags::integer)) {
-        numeric z = mod(ex_to_numeric(SixtyExOverPi),_num60());
-        if (z>=_num60()) {
-            // wrap to interval [0, Pi)
-            z -= _num60();
-        }
-        if (z>=_num30()) {
-            // wrap to interval [0, Pi/2)
-            z = _num60()-z;
-            sign = _ex_1();
-        }
-        if (z.is_equal(_num0()))  // tan(0)       -> 0
-            return _ex0();
-        if (z.is_equal(_num5()))  // tan(Pi/12)   -> 2-sqrt(3)
-            return sign*(_ex2()-power(_ex3(),_ex1_2()));
-        if (z.is_equal(_num10())) // tan(Pi/6)    -> sqrt(3)/3
-            return sign*_ex1_3()*power(_ex3(),_ex1_2());
-        if (z.is_equal(_num15())) // tan(Pi/4)    -> 1
-            return sign*_ex1();
-        if (z.is_equal(_num20())) // tan(Pi/3)    -> sqrt(3)
-            return sign*power(_ex3(),_ex1_2());
-        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"));
-    }
-    
-    if (is_ex_exactly_of_type(x, function)) {
-        ex t = x.op(0);
-        // tan(atan(x)) -> x
-        if (is_ex_the_function(x, atan))
-            return t;
-        // tan(asin(x)) -> x*(1+x^2)^(-1/2)
-        if (is_ex_the_function(x, asin))
-            return t*power(_ex1()-power(t,_ex2()),_ex_1_2());
-        // tan(acos(x)) -> (1-x^2)^(1/2)/x
-        if (is_ex_the_function(x, acos))
-            return power(t,_ex_1())*power(_ex1()-power(t,_ex2()),_ex1_2());
-    }
-    
-    // tan(float) -> float
-    if (x.info(info_flags::numeric) && !x.info(info_flags::crational)) {
-        return tan_evalf(x);
-    }
-    
-    return tan(x).hold();
+       // tan(n/d*Pi) -> { all known non-nested radicals }
+       ex SixtyExOverPi = _ex60()*x/Pi;
+       ex sign = _ex1();
+       if (SixtyExOverPi.info(info_flags::integer)) {
+               numeric z = mod(ex_to_numeric(SixtyExOverPi),_num60());
+               if (z>=_num60()) {
+                       // wrap to interval [0, Pi)
+                       z -= _num60();
+               }
+               if (z>=_num30()) {
+                       // wrap to interval [0, Pi/2)
+                       z = _num60()-z;
+                       sign = _ex_1();
+               }
+               if (z.is_equal(_num0()))  // tan(0)       -> 0
+                       return _ex0();
+               if (z.is_equal(_num5()))  // tan(Pi/12)   -> 2-sqrt(3)
+                       return sign*(_ex2()-power(_ex3(),_ex1_2()));
+               if (z.is_equal(_num10())) // tan(Pi/6)    -> sqrt(3)/3
+                       return sign*_ex1_3()*power(_ex3(),_ex1_2());
+               if (z.is_equal(_num15())) // tan(Pi/4)    -> 1
+                       return sign*_ex1();
+               if (z.is_equal(_num20())) // tan(Pi/3)    -> sqrt(3)
+                       return sign*power(_ex3(),_ex1_2());
+               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 (pole_error("tan_eval(): simple pole",1));
+       }
+       
+       if (is_ex_exactly_of_type(x, function)) {
+               ex t = x.op(0);
+               // tan(atan(x)) -> x
+               if (is_ex_the_function(x, atan))
+                       return t;
+               // tan(asin(x)) -> x*(1+x^2)^(-1/2)
+               if (is_ex_the_function(x, asin))
+                       return t*power(_ex1()-power(t,_ex2()),_ex_1_2());
+               // tan(acos(x)) -> (1-x^2)^(1/2)/x
+               if (is_ex_the_function(x, acos))
+                       return power(t,_ex_1())*power(_ex1()-power(t,_ex2()),_ex1_2());
+       }
+       
+       // tan(float) -> float
+       if (x.info(info_flags::numeric) && !x.info(info_flags::crational)) {
+               return tan_evalf(x);
+       }
+       
+       return tan(x).hold();
 }
 
 static ex tan_deriv(const ex & x, unsigned deriv_param)
 {
-    GINAC_ASSERT(deriv_param==0);
-    
-    // d/dx tan(x) -> 1+tan(x)^2;
-    return (_ex1()+power(tan(x),_ex2()));
+       GINAC_ASSERT(deriv_param==0);
+       
+       // d/dx tan(x) -> 1+tan(x)^2;
+       return (_ex1()+power(tan(x),_ex2()));
 }
 
-static ex tan_series(const ex &x, const relational &rel, int order)
+static ex tan_series(const ex &x,
+                     const relational &rel,
+                     int order,
+                     unsigned options)
 {
-    // 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(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(rel, order+2);
+       GINAC_ASSERT(is_ex_exactly_of_type(rel.lhs(),symbol));
+       // 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(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(rel, order+2, options);
 }
 
 REGISTER_FUNCTION(tan, eval_func(tan_eval).
@@ -441,45 +469,45 @@ REGISTER_FUNCTION(tan, eval_func(tan_eval).
 
 static ex asin_evalf(const ex & x)
 {
-    BEGIN_TYPECHECK
-       TYPECHECK(x,numeric)
-    END_TYPECHECK(asin(x))
-    
-    return asin(ex_to_numeric(x)); // -> numeric asin(numeric)
+       BEGIN_TYPECHECK
+          TYPECHECK(x,numeric)
+       END_TYPECHECK(asin(x))
+       
+       return asin(ex_to_numeric(x)); // -> numeric asin(numeric)
 }
 
 static ex asin_eval(const ex & x)
 {
-    if (x.info(info_flags::numeric)) {
-        // asin(0) -> 0
-        if (x.is_zero())
-            return x;
-        // asin(1/2) -> Pi/6
-        if (x.is_equal(_ex1_2()))
-            return numeric(1,6)*Pi;
-        // asin(1) -> Pi/2
-        if (x.is_equal(_ex1()))
-            return _num1_2()*Pi;
-        // asin(-1/2) -> -Pi/6
-        if (x.is_equal(_ex_1_2()))
-            return numeric(-1,6)*Pi;
-        // asin(-1) -> -Pi/2
-        if (x.is_equal(_ex_1()))
-            return _num_1_2()*Pi;
-        // asin(float) -> float
-        if (!x.info(info_flags::crational))
-            return asin_evalf(x);
-    }
-    
-    return asin(x).hold();
+       if (x.info(info_flags::numeric)) {
+               // asin(0) -> 0
+               if (x.is_zero())
+                       return x;
+               // asin(1/2) -> Pi/6
+               if (x.is_equal(_ex1_2()))
+                       return numeric(1,6)*Pi;
+               // asin(1) -> Pi/2
+               if (x.is_equal(_ex1()))
+                       return _num1_2()*Pi;
+               // asin(-1/2) -> -Pi/6
+               if (x.is_equal(_ex_1_2()))
+                       return numeric(-1,6)*Pi;
+               // asin(-1) -> -Pi/2
+               if (x.is_equal(_ex_1()))
+                       return _num_1_2()*Pi;
+               // asin(float) -> float
+               if (!x.info(info_flags::crational))
+                       return asin_evalf(x);
+       }
+       
+       return asin(x).hold();
 }
 
 static ex asin_deriv(const ex & x, unsigned deriv_param)
 {
-    GINAC_ASSERT(deriv_param==0);
-    
-    // d/dx asin(x) -> 1/sqrt(1-x^2)
-    return power(1-power(x,_ex2()),_ex_1_2());
+       GINAC_ASSERT(deriv_param==0);
+       
+       // d/dx asin(x) -> 1/sqrt(1-x^2)
+       return power(1-power(x,_ex2()),_ex_1_2());
 }
 
 REGISTER_FUNCTION(asin, eval_func(asin_eval).
@@ -492,45 +520,45 @@ REGISTER_FUNCTION(asin, eval_func(asin_eval).
 
 static ex acos_evalf(const ex & x)
 {
-    BEGIN_TYPECHECK
-       TYPECHECK(x,numeric)
-    END_TYPECHECK(acos(x))
-    
-    return acos(ex_to_numeric(x)); // -> numeric acos(numeric)
+       BEGIN_TYPECHECK
+          TYPECHECK(x,numeric)
+       END_TYPECHECK(acos(x))
+       
+       return acos(ex_to_numeric(x)); // -> numeric acos(numeric)
 }
 
 static ex acos_eval(const ex & x)
 {
-    if (x.info(info_flags::numeric)) {
-        // acos(1) -> 0
-        if (x.is_equal(_ex1()))
-            return _ex0();
-        // acos(1/2) -> Pi/3
-        if (x.is_equal(_ex1_2()))
-            return _ex1_3()*Pi;
-        // acos(0) -> Pi/2
-        if (x.is_zero())
-            return _ex1_2()*Pi;
-        // acos(-1/2) -> 2/3*Pi
-        if (x.is_equal(_ex_1_2()))
-            return numeric(2,3)*Pi;
-        // acos(-1) -> Pi
-        if (x.is_equal(_ex_1()))
-            return Pi;
-        // acos(float) -> float
-        if (!x.info(info_flags::crational))
-            return acos_evalf(x);
-    }
-    
-    return acos(x).hold();
+       if (x.info(info_flags::numeric)) {
+               // acos(1) -> 0
+               if (x.is_equal(_ex1()))
+                       return _ex0();
+               // acos(1/2) -> Pi/3
+               if (x.is_equal(_ex1_2()))
+                       return _ex1_3()*Pi;
+               // acos(0) -> Pi/2
+               if (x.is_zero())
+                       return _ex1_2()*Pi;
+               // acos(-1/2) -> 2/3*Pi
+               if (x.is_equal(_ex_1_2()))
+                       return numeric(2,3)*Pi;
+               // acos(-1) -> Pi
+               if (x.is_equal(_ex_1()))
+                       return Pi;
+               // acos(float) -> float
+               if (!x.info(info_flags::crational))
+                       return acos_evalf(x);
+       }
+       
+       return acos(x).hold();
 }
 
 static ex acos_deriv(const ex & x, unsigned deriv_param)
 {
-    GINAC_ASSERT(deriv_param==0);
-    
-    // d/dx acos(x) -> -1/sqrt(1-x^2)
-    return _ex_1()*power(1-power(x,_ex2()),_ex_1_2());
+       GINAC_ASSERT(deriv_param==0);
+       
+       // d/dx acos(x) -> -1/sqrt(1-x^2)
+       return _ex_1()*power(1-power(x,_ex2()),_ex_1_2());
 }
 
 REGISTER_FUNCTION(acos, eval_func(acos_eval).
@@ -543,38 +571,71 @@ REGISTER_FUNCTION(acos, eval_func(acos_eval).
 
 static ex atan_evalf(const ex & x)
 {
-    BEGIN_TYPECHECK
-        TYPECHECK(x,numeric)
-    END_TYPECHECK(atan(x))
-    
-    return atan(ex_to_numeric(x)); // -> numeric atan(numeric)
+       BEGIN_TYPECHECK
+               TYPECHECK(x,numeric)
+       END_TYPECHECK(atan(x))
+       
+       return atan(ex_to_numeric(x)); // -> numeric atan(numeric)
 }
 
 static ex atan_eval(const ex & x)
 {
-    if (x.info(info_flags::numeric)) {
-        // atan(0) -> 0
-        if (x.is_equal(_ex0()))
-            return _ex0();
-        // atan(float) -> float
-        if (!x.info(info_flags::crational))
-            return atan_evalf(x);
-    }
-    
-    return atan(x).hold();
-}    
+       if (x.info(info_flags::numeric)) {
+               // atan(0) -> 0
+               if (x.is_equal(_ex0()))
+                       return _ex0();
+               // atan(1) -> Pi/4
+               if (x.is_equal(_ex1()))
+                       return _ex1_4()*Pi;
+               // atan(-1) -> -Pi/4
+               if (x.is_equal(_ex_1()))
+                       return _ex_1_4()*Pi;
+               if (x.is_equal(I) || x.is_equal(-I))
+                       throw (pole_error("atan_eval(): logarithmic pole",0));
+               // atan(float) -> float
+               if (!x.info(info_flags::crational))
+                       return atan_evalf(x);
+       }
+       
+       return atan(x).hold();
+}
 
 static ex atan_deriv(const ex & x, unsigned deriv_param)
 {
-    GINAC_ASSERT(deriv_param==0);
+       GINAC_ASSERT(deriv_param==0);
 
-    // d/dx atan(x) -> 1/(1+x^2)
-    return power(_ex1()+power(x,_ex2()), _ex_1());
+       // d/dx atan(x) -> 1/(1+x^2)
+       return power(_ex1()+power(x,_ex2()), _ex_1());
+}
+
+static ex atan_series(const ex &x,
+                      const relational &rel,
+                      int order,
+                      unsigned options)
+{
+       GINAC_ASSERT(is_ex_exactly_of_type(rel.lhs(),symbol));
+       // method:
+       // Taylor series where there is no pole or cut falls back to atan_deriv.
+       // There are two branch cuts, one runnig from I up the imaginary axis and
+       // one running from -I down the imaginary axis.  The points I and -I are
+       // poles.
+       // On the branch cuts and the poles series expand
+       //     log((1+I*x)/(1-I*x))/(2*I)
+       // instead.
+       // (The constant term on the cut itself could be made simpler.)
+       const ex x_pt = x.subs(rel);
+       if (!(I*x_pt).info(info_flags::real))
+               throw do_taylor();     // Re(x) != 0
+       if ((I*x_pt).info(info_flags::real) && abs(I*x_pt)<_ex1())
+               throw do_taylor();     // Re(x) == 0, but abs(x)<1
+       // if we got here we have to care for cuts and poles
+       return (log((1+I*x)/(1-I*x))/(2*I)).series(rel, order, options);
 }
 
 REGISTER_FUNCTION(atan, eval_func(atan_eval).
                         evalf_func(atan_evalf).
-                        derivative_func(atan_deriv));
+                        derivative_func(atan_deriv).
+                        series_func(atan_series));
 
 //////////
 // inverse tangent (atan2(y,x))
@@ -582,34 +643,34 @@ REGISTER_FUNCTION(atan, eval_func(atan_eval).
 
 static ex atan2_evalf(const ex & y, const ex & x)
 {
-    BEGIN_TYPECHECK
-        TYPECHECK(y,numeric)
-        TYPECHECK(x,numeric)
-    END_TYPECHECK(atan2(y,x))
-    
-    return atan(ex_to_numeric(y),ex_to_numeric(x)); // -> numeric atan(numeric)
+       BEGIN_TYPECHECK
+               TYPECHECK(y,numeric)
+               TYPECHECK(x,numeric)
+       END_TYPECHECK(atan2(y,x))
+       
+       return atan(ex_to_numeric(y),ex_to_numeric(x)); // -> numeric atan(numeric)
 }
 
 static ex atan2_eval(const ex & y, const ex & x)
 {
-    if (y.info(info_flags::numeric) && !y.info(info_flags::crational) &&
-        x.info(info_flags::numeric) && !x.info(info_flags::crational)) {
-        return atan2_evalf(y,x);
-    }
-    
-    return atan2(y,x).hold();
+       if (y.info(info_flags::numeric) && !y.info(info_flags::crational) &&
+               x.info(info_flags::numeric) && !x.info(info_flags::crational)) {
+               return atan2_evalf(y,x);
+       }
+       
+       return atan2(y,x).hold();
 }    
 
 static ex atan2_deriv(const ex & y, const ex & x, unsigned deriv_param)
 {
-    GINAC_ASSERT(deriv_param<2);
-    
-    if (deriv_param==0) {
-        // d/dy atan(y,x)
-        return x*power(power(x,_ex2())+power(y,_ex2()),_ex_1());
-    }
-    // d/dx atan(y,x)
-    return -y*power(power(x,_ex2())+power(y,_ex2()),_ex_1());
+       GINAC_ASSERT(deriv_param<2);
+       
+       if (deriv_param==0) {
+               // d/dy atan(y,x)
+               return x*power(power(x,_ex2())+power(y,_ex2()),_ex_1());
+       }
+       // d/dx atan(y,x)
+       return -y*power(power(x,_ex2())+power(y,_ex2()),_ex_1());
 }
 
 REGISTER_FUNCTION(atan2, eval_func(atan2_eval).
@@ -622,48 +683,48 @@ REGISTER_FUNCTION(atan2, eval_func(atan2_eval).
 
 static ex sinh_evalf(const ex & x)
 {
-    BEGIN_TYPECHECK
-       TYPECHECK(x,numeric)
-    END_TYPECHECK(sinh(x))
-    
-    return sinh(ex_to_numeric(x)); // -> numeric sinh(numeric)
+       BEGIN_TYPECHECK
+          TYPECHECK(x,numeric)
+       END_TYPECHECK(sinh(x))
+       
+       return sinh(ex_to_numeric(x)); // -> numeric sinh(numeric)
 }
 
 static ex sinh_eval(const ex & x)
 {
-    if (x.info(info_flags::numeric)) {
-        if (x.is_zero())  // sinh(0) -> 0
-            return _ex0();        
-        if (!x.info(info_flags::crational))  // sinh(float) -> float
-            return sinh_evalf(x);
-    }
-    
-    if ((x/Pi).info(info_flags::numeric) &&
-        ex_to_numeric(x/Pi).real().is_zero())  // sinh(I*x) -> I*sin(x)
-        return I*sin(x/I);
-    
-    if (is_ex_exactly_of_type(x, function)) {
-        ex t = x.op(0);
-        // sinh(asinh(x)) -> x
-        if (is_ex_the_function(x, asinh))
-            return t;
-        // sinh(acosh(x)) -> (x-1)^(1/2) * (x+1)^(1/2)
-        if (is_ex_the_function(x, acosh))
-            return power(t-_ex1(),_ex1_2())*power(t+_ex1(),_ex1_2());
-        // sinh(atanh(x)) -> x*(1-x^2)^(-1/2)
-        if (is_ex_the_function(x, atanh))
-            return t*power(_ex1()-power(t,_ex2()),_ex_1_2());
-    }
-    
-    return sinh(x).hold();
+       if (x.info(info_flags::numeric)) {
+               if (x.is_zero())  // sinh(0) -> 0
+                       return _ex0();        
+               if (!x.info(info_flags::crational))  // sinh(float) -> float
+                       return sinh_evalf(x);
+       }
+       
+       if ((x/Pi).info(info_flags::numeric) &&
+               ex_to_numeric(x/Pi).real().is_zero())  // sinh(I*x) -> I*sin(x)
+               return I*sin(x/I);
+       
+       if (is_ex_exactly_of_type(x, function)) {
+               ex t = x.op(0);
+               // sinh(asinh(x)) -> x
+               if (is_ex_the_function(x, asinh))
+                       return t;
+               // sinh(acosh(x)) -> (x-1)^(1/2) * (x+1)^(1/2)
+               if (is_ex_the_function(x, acosh))
+                       return power(t-_ex1(),_ex1_2())*power(t+_ex1(),_ex1_2());
+               // sinh(atanh(x)) -> x*(1-x^2)^(-1/2)
+               if (is_ex_the_function(x, atanh))
+                       return t*power(_ex1()-power(t,_ex2()),_ex_1_2());
+       }
+       
+       return sinh(x).hold();
 }
 
 static ex sinh_deriv(const ex & x, unsigned deriv_param)
 {
-    GINAC_ASSERT(deriv_param==0);
-    
-    // d/dx sinh(x) -> cosh(x)
-    return cosh(x);
+       GINAC_ASSERT(deriv_param==0);
+       
+       // d/dx sinh(x) -> cosh(x)
+       return cosh(x);
 }
 
 REGISTER_FUNCTION(sinh, eval_func(sinh_eval).
@@ -676,48 +737,48 @@ REGISTER_FUNCTION(sinh, eval_func(sinh_eval).
 
 static ex cosh_evalf(const ex & x)
 {
-    BEGIN_TYPECHECK
-       TYPECHECK(x,numeric)
-    END_TYPECHECK(cosh(x))
-    
-    return cosh(ex_to_numeric(x)); // -> numeric cosh(numeric)
+       BEGIN_TYPECHECK
+          TYPECHECK(x,numeric)
+       END_TYPECHECK(cosh(x))
+       
+       return cosh(ex_to_numeric(x)); // -> numeric cosh(numeric)
 }
 
 static ex cosh_eval(const ex & x)
 {
-    if (x.info(info_flags::numeric)) {
-        if (x.is_zero())  // cosh(0) -> 1
-            return _ex1();
-        if (!x.info(info_flags::crational))  // cosh(float) -> float
-            return cosh_evalf(x);
-    }
-    
-    if ((x/Pi).info(info_flags::numeric) &&
-        ex_to_numeric(x/Pi).real().is_zero())  // cosh(I*x) -> cos(x)
-        return cos(x/I);
-    
-    if (is_ex_exactly_of_type(x, function)) {
-        ex t = x.op(0);
-        // cosh(acosh(x)) -> x
-        if (is_ex_the_function(x, acosh))
-            return t;
-        // cosh(asinh(x)) -> (1+x^2)^(1/2)
-        if (is_ex_the_function(x, asinh))
-            return power(_ex1()+power(t,_ex2()),_ex1_2());
-        // cosh(atanh(x)) -> (1-x^2)^(-1/2)
-        if (is_ex_the_function(x, atanh))
-            return power(_ex1()-power(t,_ex2()),_ex_1_2());
-    }
-    
-    return cosh(x).hold();
+       if (x.info(info_flags::numeric)) {
+               if (x.is_zero())  // cosh(0) -> 1
+                       return _ex1();
+               if (!x.info(info_flags::crational))  // cosh(float) -> float
+                       return cosh_evalf(x);
+       }
+       
+       if ((x/Pi).info(info_flags::numeric) &&
+               ex_to_numeric(x/Pi).real().is_zero())  // cosh(I*x) -> cos(x)
+               return cos(x/I);
+       
+       if (is_ex_exactly_of_type(x, function)) {
+               ex t = x.op(0);
+               // cosh(acosh(x)) -> x
+               if (is_ex_the_function(x, acosh))
+                       return t;
+               // cosh(asinh(x)) -> (1+x^2)^(1/2)
+               if (is_ex_the_function(x, asinh))
+                       return power(_ex1()+power(t,_ex2()),_ex1_2());
+               // cosh(atanh(x)) -> (1-x^2)^(-1/2)
+               if (is_ex_the_function(x, atanh))
+                       return power(_ex1()-power(t,_ex2()),_ex_1_2());
+       }
+       
+       return cosh(x).hold();
 }
 
 static ex cosh_deriv(const ex & x, unsigned deriv_param)
 {
-    GINAC_ASSERT(deriv_param==0);
-    
-    // d/dx cosh(x) -> sinh(x)
-    return sinh(x);
+       GINAC_ASSERT(deriv_param==0);
+       
+       // d/dx cosh(x) -> sinh(x)
+       return sinh(x);
 }
 
 REGISTER_FUNCTION(cosh, eval_func(cosh_eval).
@@ -731,60 +792,64 @@ REGISTER_FUNCTION(cosh, eval_func(cosh_eval).
 
 static ex tanh_evalf(const ex & x)
 {
-    BEGIN_TYPECHECK
-       TYPECHECK(x,numeric)
-    END_TYPECHECK(tanh(x))
-    
-    return tanh(ex_to_numeric(x)); // -> numeric tanh(numeric)
+       BEGIN_TYPECHECK
+          TYPECHECK(x,numeric)
+       END_TYPECHECK(tanh(x))
+       
+       return tanh(ex_to_numeric(x)); // -> numeric tanh(numeric)
 }
 
 static ex tanh_eval(const ex & x)
 {
-    if (x.info(info_flags::numeric)) {
-        if (x.is_zero())  // tanh(0) -> 0
-            return _ex0();
-        if (!x.info(info_flags::crational))  // tanh(float) -> float
-            return tanh_evalf(x);
-    }
-    
-    if ((x/Pi).info(info_flags::numeric) &&
-        ex_to_numeric(x/Pi).real().is_zero())  // tanh(I*x) -> I*tan(x);
-        return I*tan(x/I);
-    
-    if (is_ex_exactly_of_type(x, function)) {
-        ex t = x.op(0);
-        // tanh(atanh(x)) -> x
-        if (is_ex_the_function(x, atanh))
-            return t;
-        // tanh(asinh(x)) -> x*(1+x^2)^(-1/2)
-        if (is_ex_the_function(x, asinh))
-            return t*power(_ex1()+power(t,_ex2()),_ex_1_2());
-        // tanh(acosh(x)) -> (x-1)^(1/2)*(x+1)^(1/2)/x
-        if (is_ex_the_function(x, acosh))
-            return power(t-_ex1(),_ex1_2())*power(t+_ex1(),_ex1_2())*power(t,_ex_1());
-    }
-    
-    return tanh(x).hold();
+       if (x.info(info_flags::numeric)) {
+               if (x.is_zero())  // tanh(0) -> 0
+                       return _ex0();
+               if (!x.info(info_flags::crational))  // tanh(float) -> float
+                       return tanh_evalf(x);
+       }
+       
+       if ((x/Pi).info(info_flags::numeric) &&
+               ex_to_numeric(x/Pi).real().is_zero())  // tanh(I*x) -> I*tan(x);
+               return I*tan(x/I);
+       
+       if (is_ex_exactly_of_type(x, function)) {
+               ex t = x.op(0);
+               // tanh(atanh(x)) -> x
+               if (is_ex_the_function(x, atanh))
+                       return t;
+               // tanh(asinh(x)) -> x*(1+x^2)^(-1/2)
+               if (is_ex_the_function(x, asinh))
+                       return t*power(_ex1()+power(t,_ex2()),_ex_1_2());
+               // tanh(acosh(x)) -> (x-1)^(1/2)*(x+1)^(1/2)/x
+               if (is_ex_the_function(x, acosh))
+                       return power(t-_ex1(),_ex1_2())*power(t+_ex1(),_ex1_2())*power(t,_ex_1());
+       }
+       
+       return tanh(x).hold();
 }
 
 static ex tanh_deriv(const ex & x, unsigned deriv_param)
 {
-    GINAC_ASSERT(deriv_param==0);
-    
-    // d/dx tanh(x) -> 1-tanh(x)^2
-    return _ex1()-power(tanh(x),_ex2());
+       GINAC_ASSERT(deriv_param==0);
+       
+       // d/dx tanh(x) -> 1-tanh(x)^2
+       return _ex1()-power(tanh(x),_ex2());
 }
 
-static ex tanh_series(const ex &x, const relational &rel, int order)
+static ex tanh_series(const ex &x,
+                      const relational &rel,
+                      int order,
+                      unsigned options)
 {
-    // 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(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(rel, order+2);
+       GINAC_ASSERT(is_ex_exactly_of_type(rel.lhs(),symbol));
+       // 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(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(rel, order+2, options);
 }
 
 REGISTER_FUNCTION(tanh, eval_func(tanh_eval).
@@ -798,33 +863,33 @@ REGISTER_FUNCTION(tanh, eval_func(tanh_eval).
 
 static ex asinh_evalf(const ex & x)
 {
-    BEGIN_TYPECHECK
-       TYPECHECK(x,numeric)
-    END_TYPECHECK(asinh(x))
-    
-    return asinh(ex_to_numeric(x)); // -> numeric asinh(numeric)
+       BEGIN_TYPECHECK
+          TYPECHECK(x,numeric)
+       END_TYPECHECK(asinh(x))
+       
+       return asinh(ex_to_numeric(x)); // -> numeric asinh(numeric)
 }
 
 static ex asinh_eval(const ex & x)
 {
-    if (x.info(info_flags::numeric)) {
-        // asinh(0) -> 0
-        if (x.is_zero())
-            return _ex0();
-        // asinh(float) -> float
-        if (!x.info(info_flags::crational))
-            return asinh_evalf(x);
-    }
-    
-    return asinh(x).hold();
+       if (x.info(info_flags::numeric)) {
+               // asinh(0) -> 0
+               if (x.is_zero())
+                       return _ex0();
+               // asinh(float) -> float
+               if (!x.info(info_flags::crational))
+                       return asinh_evalf(x);
+       }
+       
+       return asinh(x).hold();
 }
 
 static ex asinh_deriv(const ex & x, unsigned deriv_param)
 {
-    GINAC_ASSERT(deriv_param==0);
-    
-    // d/dx asinh(x) -> 1/sqrt(1+x^2)
-    return power(_ex1()+power(x,_ex2()),_ex_1_2());
+       GINAC_ASSERT(deriv_param==0);
+       
+       // d/dx asinh(x) -> 1/sqrt(1+x^2)
+       return power(_ex1()+power(x,_ex2()),_ex_1_2());
 }
 
 REGISTER_FUNCTION(asinh, eval_func(asinh_eval).
@@ -837,39 +902,39 @@ REGISTER_FUNCTION(asinh, eval_func(asinh_eval).
 
 static ex acosh_evalf(const ex & x)
 {
-    BEGIN_TYPECHECK
-       TYPECHECK(x,numeric)
-    END_TYPECHECK(acosh(x))
-    
-    return acosh(ex_to_numeric(x)); // -> numeric acosh(numeric)
+       BEGIN_TYPECHECK
+          TYPECHECK(x,numeric)
+       END_TYPECHECK(acosh(x))
+       
+       return acosh(ex_to_numeric(x)); // -> numeric acosh(numeric)
 }
 
 static ex acosh_eval(const ex & x)
 {
-    if (x.info(info_flags::numeric)) {
-        // acosh(0) -> Pi*I/2
-        if (x.is_zero())
-            return Pi*I*numeric(1,2);
-        // acosh(1) -> 0
-        if (x.is_equal(_ex1()))
-            return _ex0();
-        // acosh(-1) -> Pi*I
-        if (x.is_equal(_ex_1()))
-            return Pi*I;
-        // acosh(float) -> float
-        if (!x.info(info_flags::crational))
-            return acosh_evalf(x);
-    }
-    
-    return acosh(x).hold();
+       if (x.info(info_flags::numeric)) {
+               // acosh(0) -> Pi*I/2
+               if (x.is_zero())
+                       return Pi*I*numeric(1,2);
+               // acosh(1) -> 0
+               if (x.is_equal(_ex1()))
+                       return _ex0();
+               // acosh(-1) -> Pi*I
+               if (x.is_equal(_ex_1()))
+                       return Pi*I;
+               // acosh(float) -> float
+               if (!x.info(info_flags::crational))
+                       return acosh_evalf(x);
+       }
+       
+       return acosh(x).hold();
 }
 
 static ex acosh_deriv(const ex & x, unsigned deriv_param)
 {
-    GINAC_ASSERT(deriv_param==0);
-    
-    // d/dx acosh(x) -> 1/(sqrt(x-1)*sqrt(x+1))
-    return power(x+_ex_1(),_ex_1_2())*power(x+_ex1(),_ex_1_2());
+       GINAC_ASSERT(deriv_param==0);
+       
+       // d/dx acosh(x) -> 1/(sqrt(x-1)*sqrt(x+1))
+       return power(x+_ex_1(),_ex_1_2())*power(x+_ex1(),_ex_1_2());
 }
 
 REGISTER_FUNCTION(acosh, eval_func(acosh_eval).
@@ -882,41 +947,66 @@ REGISTER_FUNCTION(acosh, eval_func(acosh_eval).
 
 static ex atanh_evalf(const ex & x)
 {
-    BEGIN_TYPECHECK
-       TYPECHECK(x,numeric)
-    END_TYPECHECK(atanh(x))
-    
-    return atanh(ex_to_numeric(x)); // -> numeric atanh(numeric)
+       BEGIN_TYPECHECK
+          TYPECHECK(x,numeric)
+       END_TYPECHECK(atanh(x))
+       
+       return atanh(ex_to_numeric(x)); // -> numeric atanh(numeric)
 }
 
 static ex atanh_eval(const ex & x)
 {
-    if (x.info(info_flags::numeric)) {
-        // atanh(0) -> 0
-        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"));
-        // atanh(float) -> float
-        if (!x.info(info_flags::crational))
-            return atanh_evalf(x);
-    }
-    
-    return atanh(x).hold();
+       if (x.info(info_flags::numeric)) {
+               // atanh(0) -> 0
+               if (x.is_zero())
+                       return _ex0();
+               // atanh({+|-}1) -> throw
+               if (x.is_equal(_ex1()) || x.is_equal(_ex_1()))
+                       throw (pole_error("atanh_eval(): logarithmic pole",0));
+               // atanh(float) -> float
+               if (!x.info(info_flags::crational))
+                       return atanh_evalf(x);
+       }
+       
+       return atanh(x).hold();
 }
 
 static ex atanh_deriv(const ex & x, unsigned deriv_param)
 {
-    GINAC_ASSERT(deriv_param==0);
-    
-    // d/dx atanh(x) -> 1/(1-x^2)
-    return power(_ex1()-power(x,_ex2()),_ex_1());
+       GINAC_ASSERT(deriv_param==0);
+       
+       // d/dx atanh(x) -> 1/(1-x^2)
+       return power(_ex1()-power(x,_ex2()),_ex_1());
+}
+
+static ex atanh_series(const ex &x,
+                       const relational &rel,
+                       int order,
+                       unsigned options)
+{
+       GINAC_ASSERT(is_ex_exactly_of_type(rel.lhs(),symbol));
+       // method:
+       // Taylor series where there is no pole or cut falls back to atan_deriv.
+       // There are two branch cuts, one runnig from 1 up the real axis and one
+       // one running from -1 down the real axis.  The points 1 and -1 are poles
+       // On the branch cuts and the poles series expand
+       //     log((1+x)/(1-x))/(2*I)
+       // instead.
+       // (The constant term on the cut itself could be made simpler.)
+       const ex x_pt = x.subs(rel);
+       if (!(x_pt).info(info_flags::real))
+               throw do_taylor();     // Im(x) != 0
+       if ((x_pt).info(info_flags::real) && abs(x_pt)<_ex1())
+               throw do_taylor();     // Im(x) == 0, but abs(x)<1
+       // if we got here we have to care for cuts and poles
+       return (log((1+x)/(1-x))/2).series(rel, order, options);
 }
 
 REGISTER_FUNCTION(atanh, eval_func(atanh_eval).
                          evalf_func(atanh_evalf).
-                         derivative_func(atanh_deriv));
+                         derivative_func(atanh_deriv).
+                         series_func(atanh_series));
+
 
 #ifndef NO_NAMESPACE_GINAC
 } // namespace GiNaC