* add .imag() function

* fix a very old bug in EigenSolver that I had completely forgotten
  (thanks to Timothy to refresh my mind)
* fix doc of Matrix::Map

Eigen/src/Core/CwiseUnaryOp.h

@@ -174,13 +174,17 @@ MatrixBase<Derived>::conjugate() const
 
 /** \returns an expression of the real part of \c *this.
   *
-  * \sa adjoint() */
+  * \sa imag() */
 template<typename Derived>
 inline const typename MatrixBase<Derived>::RealReturnType
-MatrixBase<Derived>::real() const
-{
-  return derived();
-}
+MatrixBase<Derived>::real() const { return derived(); }
+
+/** \returns an expression of the imaginary part of \c *this.
+  *
+  * \sa real() */
+template<typename Derived>
+inline const typename MatrixBase<Derived>::ImagReturnType
+MatrixBase<Derived>::imag() const { return derived(); }
 
 /** \returns an expression of *this with the \a Scalar type casted to
   * \a NewScalar.

Eigen/src/Core/Functors.h

@@ -240,7 +240,21 @@ struct ei_scalar_real_op EIGEN_EMPTY_STRUCT {
 };
 template<typename Scalar>
 struct ei_functor_traits<ei_scalar_real_op<Scalar> >
-{ enum { Cost =  0, PacketAccess = false }; };
+{ enum { Cost = 0, PacketAccess = false }; };
+
+/** \internal
+  * \brief Template functor to extract the imaginary part of a complex
+  *
+  * \sa class CwiseUnaryOp, MatrixBase::imag()
+  */
+template<typename Scalar>
+struct ei_scalar_imag_op EIGEN_EMPTY_STRUCT {
+  typedef typename NumTraits<Scalar>::Real result_type;
+  inline result_type operator() (const Scalar& a) const { return ei_imag(a); }
+};
+template<typename Scalar>
+struct ei_functor_traits<ei_scalar_imag_op<Scalar> >
+{ enum { Cost = 0, PacketAccess = false }; };
 
 /** \internal
   * \brief Template functor to multiply a scalar by a fixed other one

Eigen/src/Core/Matrix.h

@@ -437,14 +437,14 @@ class Matrix
         this->Base::swap(other);
     }
 
-    /**
+    /** \name Map
       * These are convenience functions returning Map objects. The Map() static functions return unaligned Map objects,
       * while the AlignedMap() functions return aligned Map objects and thus should be called only with 16-byte-aligned
       * \a data pointers.
-      * 
+      *
       * \see class Map
       */
-    //@}
+    //@{
     inline static const UnalignedMapType Map(const Scalar* data)
     { return UnalignedMapType(data); }
     inline static UnalignedMapType Map(Scalar* data)

Eigen/src/Core/MatrixBase.h

@@ -189,6 +189,8 @@ template<typename Derived> class MatrixBase
                      >::ret ConjugateReturnType;
     /** \internal the return type of MatrixBase::real() */
     typedef CwiseUnaryOp<ei_scalar_real_op<Scalar>, Derived> RealReturnType;
+    /** \internal the return type of MatrixBase::imag() */
+    typedef CwiseUnaryOp<ei_scalar_imag_op<Scalar>, Derived> ImagReturnType;
     /** \internal the return type of MatrixBase::adjoint() */
     typedef Eigen::Transpose<NestByValue<typename ei_cleantype<ConjugateReturnType>::type> >
             AdjointReturnType;
@@ -496,6 +498,7 @@ template<typename Derived> class MatrixBase
 
     ConjugateReturnType conjugate() const;
     const RealReturnType real() const;
+    const ImagReturnType imag() const;
 
     template<typename CustomUnaryOp>
     const CwiseUnaryOp<CustomUnaryOp, Derived> unaryExpr(const CustomUnaryOp& func = CustomUnaryOp()) const;

Eigen/src/Core/util/ForwardDeclarations.h

@@ -64,6 +64,7 @@ template<typename Scalar> struct ei_scalar_quotient_op;
 template<typename Scalar> struct ei_scalar_opposite_op;
 template<typename Scalar> struct ei_scalar_conjugate_op;
 template<typename Scalar> struct ei_scalar_real_op;
+template<typename Scalar> struct ei_scalar_imag_op;
 template<typename Scalar> struct ei_scalar_abs_op;
 template<typename Scalar> struct ei_scalar_abs2_op;
 template<typename Scalar> struct ei_scalar_sqrt_op;