- Banned exZERO(), exONE(), exMINUSHALF() and all this from the interface.

[ginac.git] / ginac / inifcns_zeta.cpp

diff --git a/ginac/inifcns_zeta.cpp b/ginac/inifcns_zeta.cpp
index ae58ec1630cb103a6e2898ee0690386364e79294..9fdce1e84d69eec301b8a32ba1a0d38ec9b283f1 100644 (file)
--- a/ginac/inifcns_zeta.cpp
+++ b/ginac/inifcns_zeta.cpp
@@ -29,60 +29,89 @@
 #include "numeric.h"
 #include "power.h"
 #include "symbol.h"
+#include "utils.h"
 
+#ifndef NO_GINAC_NAMESPACE
 namespace GiNaC {
+#endif // ndef NO_GINAC_NAMESPACE
 
 //////////
 // Riemann's Zeta-function
 //////////
 
-static ex zeta_eval(ex const & x)
+static ex zeta1_evalf(ex const & x)
+{
+    BEGIN_TYPECHECK
+        TYPECHECK(x,numeric)
+    END_TYPECHECK(zeta(x))
+        
+    return zeta(ex_to_numeric(x));
+}
+
+static ex zeta1_eval(ex const & x)
 {
     if (x.info(info_flags::numeric)) {
         numeric y = ex_to_numeric(x);
         // trap integer arguments:
         if (y.is_integer()) {
             if (y.is_zero())
-                return -exHALF();
-            if (!x.compare(exONE()))
+                return -_ex1_2();
+            if (x.is_equal(_ex1()))
                 throw(std::domain_error("zeta(1): infinity"));
             if (x.info(info_flags::posint)) {
                 if (x.info(info_flags::odd))
                     return zeta(x).hold();
                 else
-                    return abs(bernoulli(y))*pow(Pi,x)*numTWO().power(y-numONE())/factorial(y);
+                    return abs(bernoulli(y))*pow(Pi,x)*_num2().power(y-_num1())/factorial(y);
             } else {
                 if (x.info(info_flags::odd))
-                    return -bernoulli(numONE()-y)/(numONE()-y);
+                    return -bernoulli(_num1()-y)/(_num1()-y);
                 else
-                    return numZERO();
+                    return _num0();
             }
         }
     }
     return zeta(x).hold();
 }
 
-static ex zeta_evalf(ex const & x)
+static ex zeta1_diff(ex const & x, unsigned diff_param)
 {
-    BEGIN_TYPECHECK
-        TYPECHECK(x,numeric)
-    END_TYPECHECK(zeta(x))
+    GINAC_ASSERT(diff_param==0);
     
-    return zeta(ex_to_numeric(x));
+    return zeta(_ex1(), x);
 }
 
-static ex zeta_diff(ex const & x, unsigned diff_param)
+const unsigned function_index_zeta1 = function::register_new("zeta", zeta1_eval, zeta1_evalf, zeta1_diff, NULL);
+
+//////////
+// Derivatives of Riemann's Zeta-function  zeta(0,x)==zeta(x)
+//////////
+
+static ex zeta2_eval(ex const & n, ex const & x)
 {
-    ASSERT(diff_param==0);
+    if (n.info(info_flags::numeric)) {
+        // zeta(0,x) -> zeta(x)
+        if (n.is_zero())
+            return zeta(x);
+    }
     
-    return exZERO();  // should return zeta(numONE(),x);
+    return zeta(n, x).hold();
 }
 
-static ex zeta_series(ex const & x, symbol const & s, ex const & point, int order)
+static ex zeta2_diff(ex const & n, ex const & x, unsigned diff_param)
 {
-    throw(std::logic_error("don't know the series expansion of the zeta function"));
+    GINAC_ASSERT(diff_param<2);
+    
+    if (diff_param==0) {
+        // d/dn zeta(n,x)
+        throw(std::logic_error("cannot diff zeta(n,x) with respect to n"));
+    }
+    // d/dx psi(n,x)
+    return zeta(n+1,x);
 }
 
-REGISTER_FUNCTION(zeta, zeta_eval, zeta_evalf, zeta_diff, zeta_series);
+const unsigned function_index_zeta2 = function::register_new("zeta", zeta2_eval, NULL, zeta2_diff, NULL);
 
+#ifndef NO_GINAC_NAMESPACE
 } // namespace GiNaC
+#endif // ndef NO_GINAC_NAMESPACE