Improve doc of special math functions

1 files changed, 22 insertions, 4 deletions

diff --git a/Eigen/src/Core/GlobalFunctions.h b/Eigen/src/Core/GlobalFunctions.h
index 2173e026d..c7d73ff66 100644
--- a/Eigen/src/Core/GlobalFunctions.h
+++ b/Eigen/src/Core/GlobalFunctions.h
@@ -117,8 +117,8 @@ namespace Eigen
   }
   
   /**
-  * \brief Component-wise division of a scalar by array elements.
-  **/
+    * \brief Component-wise division of a scalar by array elements.
+    **/
   template <typename Derived>
   inline const Eigen::CwiseUnaryOp<Eigen::internal::scalar_inverse_mult_op<typename Derived::Scalar>, const Derived>
     operator/(const typename Derived::Scalar& s, const Eigen::ArrayBase<Derived>& a)
@@ -129,10 +129,15 @@ namespace Eigen
     );
   }
 
-  /** \returns an expression of the coefficient-wise igamma(\a a, \a x) to the given arrays.
+  /** \cpp11 \returns an expression of the coefficient-wise igamma(\a a, \a x) to the given arrays.
     *
     * This function computes the coefficient-wise incomplete gamma function.
     *
+    * \note This function supports only float and double scalar types in c++11 mode. To support other scalar types,
+    * or float/double in non c++11 mode, the user has to provide implementations of igammac(T,T) for any scalar
+    * type T to be supported.
+    *
+    * \sa Eigen::igammac(), Eigen::lgamma()
     */
   template<typename Derived,typename ExponentDerived>
   inline const Eigen::CwiseBinaryOp<Eigen::internal::scalar_igamma_op<typename Derived::Scalar>, const Derived, const ExponentDerived>
@@ -144,10 +149,15 @@ namespace Eigen
     );
   }
 
-  /** \returns an expression of the coefficient-wise igammac(\a a, \a x) to the given arrays.
+  /** \cpp11 \returns an expression of the coefficient-wise igammac(\a a, \a x) to the given arrays.
     *
     * This function computes the coefficient-wise complementary incomplete gamma function.
     *
+    * \note This function supports only float and double scalar types in c++11 mode. To support other scalar types,
+    * or float/double in non c++11 mode, the user has to provide implementations of igammac(T,T) for any scalar
+    * type T to be supported.
+    *
+    * \sa Eigen::igamma(), Eigen::lgamma()
     */
   template<typename Derived,typename ExponentDerived>
   inline const Eigen::CwiseBinaryOp<Eigen::internal::scalar_igammac_op<typename Derived::Scalar>, const Derived, const ExponentDerived>
@@ -163,6 +173,11 @@ namespace Eigen
     *
     * It returns the \a n -th derivative of the digamma(psi) evaluated at \c x.
     *
+    * \note This function supports only float and double scalar types in c++11 mode. To support other scalar types,
+    * or float/double in non c++11 mode, the user has to provide implementations of polygamma(T,T) for any scalar
+    * type T to be supported.
+    *
+    * \sa Eigen::digamma()
     */
   // * \warning Be careful with the order of the parameters: x.polygamma(n) is equivalent to polygamma(n,x)
   // * \sa ArrayBase::polygamma()
@@ -183,6 +198,9 @@ namespace Eigen
     * \param x is the exposent, it must be > 1
     * \param q is the shift, it must be > 0
     *
+    * \note This function supports only float and double scalar types. To support other scalar types, the user has
+    * to provide implementations of zeta(T,T) for any scalar type T to be supported.
+    *
     * \sa ArrayBase::zeta()
     */
   template<typename DerivedX,typename DerivedQ>