- fixed differentiation of gamma(x)

[ginac.git] / ginac / numeric.cpp

diff --git a/ginac/numeric.cpp b/ginac/numeric.cpp
index cc4faf3027d890e4e5876f272cd507ffbc9541e3..ef2784172107f22965381b271e2fafcd92d7bbca 100644 (file)
--- a/ginac/numeric.cpp
+++ b/ginac/numeric.cpp
@@ -519,7 +519,7 @@ numeric const & numeric::operator=(char const * s)
  *  csgn(x)==0 for x==0, csgn(x)==1 for Re(x)>0 or Re(x)=0 and Im(x)>0,
  *  csgn(x)==-1 for Re(x)<0 or Re(x)=0 and Im(x)<0.
  *
  *  csgn(x)==0 for x==0, csgn(x)==1 for Re(x)>0 or Re(x)=0 and Im(x)>0,
  *  csgn(x)==-1 for Re(x)<0 or Re(x)=0 and Im(x)<0.
  *

- *  @see numeric::compare(numeric const @ other) */
+ *  @see numeric::compare(numeric const & other) */

 int numeric::csgn(void) const
 {
     if (is_zero())
 int numeric::csgn(void) const
 {
     if (is_zero())


@@ -1063,10 +1063,18 @@ numeric atanh(numeric const & x)
 }
 
 /** The gamma function.
 }
 
 /** The gamma function.

- *  stub stub stub stub stub stub! */
+ *  This is only a stub! */

 numeric gamma(numeric const & x)
 {
 numeric gamma(numeric const & x)
 {

-    clog << "gamma(): Nobody expects the Spanish inquisition" << endl;
+    clog << "gamma(): Does anybody know good way to calculate this numerically?" << endl;
+    return numeric(0);
+}
+
+/** The psi function (aka polygamma function).
+ *  This is only a stub! */
+numeric psi(numeric const & n, numeric const & x)
+{
+    clog << "psi(): Does anybody know good way to calculate this numerically?" << endl;

     return numeric(0);
 }
 
     return numeric(0);
 }