* doc improvements in Cwise and PartialRedux:

- 33 new snippets
  - unfuck doxygen output in Cwise (issues with function macros)
  - more see-also links from outside, making Cwise more discoverable
* rename matrixNorm() to operatorNorm(). There are many matrix norms
  (the L2 is another one) but only one is called the operator norm.
  Risk of confusion with keyword operator is not too scary after all.

Eigen/src/Array/CwiseOperators.h

@@ -29,7 +29,13 @@
 
 /** \array_module
   * 
-  * \returns an expression of the coefficient-wise square root of *this. */
+  * \returns an expression of the coefficient-wise square root of *this.
+  *
+  * Example: \include Cwise_sqrt.cpp
+  * Output: \verbinclude Cwise_sqrt.out
+  *
+  * \sa pow(), square()
+  */
 template<typename ExpressionType>
 inline const EIGEN_CWISE_UNOP_RETURN_TYPE(ei_scalar_sqrt_op)
 Cwise<ExpressionType>::sqrt() const
@@ -39,7 +45,13 @@ Cwise<ExpressionType>::sqrt() const
 
 /** \array_module
   * 
-  * \returns an expression of the coefficient-wise exponential of *this. */
+  * \returns an expression of the coefficient-wise exponential of *this.
+  *
+  * Example: \include Cwise_exp.cpp
+  * Output: \verbinclude Cwise_exp.out
+  *
+  * \sa pow(), log(), sin(), cos()
+  */
 template<typename ExpressionType>
 inline const EIGEN_CWISE_UNOP_RETURN_TYPE(ei_scalar_exp_op)
 Cwise<ExpressionType>::exp() const
@@ -49,7 +61,13 @@ Cwise<ExpressionType>::exp() const
 
 /** \array_module
   * 
-  * \returns an expression of the coefficient-wise logarithm of *this. */
+  * \returns an expression of the coefficient-wise logarithm of *this.
+  *
+  * Example: \include Cwise_log.cpp
+  * Output: \verbinclude Cwise_log.out
+  *
+  * \sa exp()
+  */
 template<typename ExpressionType>
 inline const EIGEN_CWISE_UNOP_RETURN_TYPE(ei_scalar_log_op)
 Cwise<ExpressionType>::log() const
@@ -59,7 +77,13 @@ Cwise<ExpressionType>::log() const
 
 /** \array_module
   * 
-  * \returns an expression of the coefficient-wise cosine of *this. */
+  * \returns an expression of the coefficient-wise cosine of *this.
+  *
+  * Example: \include Cwise_cos.cpp
+  * Output: \verbinclude Cwise_cos.out
+  *
+  * \sa sin(), exp()
+  */
 template<typename ExpressionType>
 inline const EIGEN_CWISE_UNOP_RETURN_TYPE(ei_scalar_cos_op)
 Cwise<ExpressionType>::cos() const
@@ -70,7 +94,13 @@ Cwise<ExpressionType>::cos() const
 
 /** \array_module
   * 
-  * \returns an expression of the coefficient-wise sine of *this. */
+  * \returns an expression of the coefficient-wise sine of *this.
+  *
+  * Example: \include Cwise_sin.cpp
+  * Output: \verbinclude Cwise_sin.out
+  *
+  * \sa cos(), exp()
+  */
 template<typename ExpressionType>
 inline const EIGEN_CWISE_UNOP_RETURN_TYPE(ei_scalar_sin_op)
 Cwise<ExpressionType>::sin() const
@@ -81,7 +111,13 @@ Cwise<ExpressionType>::sin() const
 
 /** \array_module
   * 
-  * \returns an expression of the coefficient-wise power of *this to the given exponent. */
+  * \returns an expression of the coefficient-wise power of *this to the given exponent.
+  *
+  * Example: \include Cwise_pow.cpp
+  * Output: \verbinclude Cwise_pow.out
+  *
+  * \sa exp(), log()
+  */
 template<typename ExpressionType>
 inline const EIGEN_CWISE_UNOP_RETURN_TYPE(ei_scalar_pow_op)
 Cwise<ExpressionType>::pow(const Scalar& exponent) const
@@ -92,7 +128,13 @@ Cwise<ExpressionType>::pow(const Scalar& exponent) const
 
 /** \array_module
   * 
-  * \returns an expression of the coefficient-wise inverse of *this. */
+  * \returns an expression of the coefficient-wise inverse of *this.
+  *
+  * Example: \include Cwise_inverse.cpp
+  * Output: \verbinclude Cwise_inverse.out
+  *
+  * \sa operator/(), operator*()
+  */
 template<typename ExpressionType>
 inline const EIGEN_CWISE_UNOP_RETURN_TYPE(ei_scalar_inverse_op)
 Cwise<ExpressionType>::inverse() const
@@ -102,7 +144,13 @@ Cwise<ExpressionType>::inverse() const
 
 /** \array_module
   *
-  * \returns an expression of the coefficient-wise square of *this. */
+  * \returns an expression of the coefficient-wise square of *this.
+  *
+  * Example: \include Cwise_square.cpp
+  * Output: \verbinclude Cwise_square.out
+  *
+  * \sa operator/(), operator*(), abs2()
+  */
 template<typename ExpressionType>
 inline const EIGEN_CWISE_UNOP_RETURN_TYPE(ei_scalar_square_op)
 Cwise<ExpressionType>::square() const
@@ -112,7 +160,13 @@ Cwise<ExpressionType>::square() const
 
 /** \array_module
   *
-  * \returns an expression of the coefficient-wise cube of *this. */
+  * \returns an expression of the coefficient-wise cube of *this.
+  *
+  * Example: \include Cwise_cube.cpp
+  * Output: \verbinclude Cwise_cube.out
+  *
+  * \sa square(), pow()
+  */
 template<typename ExpressionType>
 inline const EIGEN_CWISE_UNOP_RETURN_TYPE(ei_scalar_cube_op)
 Cwise<ExpressionType>::cube() const
@@ -127,9 +181,10 @@ Cwise<ExpressionType>::cube() const
   * 
   * \returns an expression of the coefficient-wise \< operator of *this and \a other
   *
-  * See MatrixBase::all() for an example.
+  * Example: \include Cwise_less.cpp
+  * Output: \verbinclude Cwise_less.out
   *
-  * \sa class CwiseBinaryOp
+  * \sa MatrixBase::all(), MatrixBase::any(), operator>(), operator<=()
   */
 template<typename ExpressionType>
 template<typename OtherDerived>
@@ -143,7 +198,10 @@ Cwise<ExpressionType>::operator<(const MatrixBase<OtherDerived> &other) const
   * 
   * \returns an expression of the coefficient-wise \<= operator of *this and \a other
   *
-  * \sa class CwiseBinaryOp
+  * Example: \include Cwise_less_equal.cpp
+  * Output: \verbinclude Cwise_less_equal.out
+  *
+  * \sa MatrixBase::all(), MatrixBase::any(), operator>=(), operator<()
   */
 template<typename ExpressionType>
 template<typename OtherDerived>
@@ -157,9 +215,10 @@ Cwise<ExpressionType>::operator<=(const MatrixBase<OtherDerived> &other) const
   * 
   * \returns an expression of the coefficient-wise \> operator of *this and \a other
   *
-  * See MatrixBase::all() for an example.
+  * Example: \include Cwise_greater.cpp
+  * Output: \verbinclude Cwise_greater.out
   *
-  * \sa class CwiseBinaryOp
+  * \sa MatrixBase::all(), MatrixBase::any(), operator>=(), operator<()
   */
 template<typename ExpressionType>
 template<typename OtherDerived>
@@ -173,7 +232,10 @@ Cwise<ExpressionType>::operator>(const MatrixBase<OtherDerived> &other) const
   * 
   * \returns an expression of the coefficient-wise \>= operator of *this and \a other
   *
-  * \sa class CwiseBinaryOp
+  * Example: \include Cwise_greater_equal.cpp
+  * Output: \verbinclude Cwise_greater_equal.out
+  *
+  * \sa MatrixBase::all(), MatrixBase::any(), operator>(), operator<=()
   */
 template<typename ExpressionType>
 template<typename OtherDerived>
@@ -187,7 +249,15 @@ Cwise<ExpressionType>::operator>=(const MatrixBase<OtherDerived> &other) const
   * 
   * \returns an expression of the coefficient-wise == operator of *this and \a other
   *
-  * \sa class CwiseBinaryOp
+  * \warning this performs an exact comparison, which is generally a bad idea with floating-point types.
+  * In order to check for equality between two vectors or matrices with floating-point coefficients, it is
+  * generally a far better idea to use a fuzzy comparison as provided by MatrixBase::isApprox() and
+  * MatrixBase::isMuchSmallerThan().
+  *
+  * Example: \include Cwise_equal_equal.cpp
+  * Output: \verbinclude Cwise_equal_equal.out
+  *
+  * \sa MatrixBase::all(), MatrixBase::any(), MatrixBase::isApprox(), MatrixBase::isMuchSmallerThan()
   */
 template<typename ExpressionType>
 template<typename OtherDerived>
@@ -201,7 +271,15 @@ Cwise<ExpressionType>::operator==(const MatrixBase<OtherDerived> &other) const
   * 
   * \returns an expression of the coefficient-wise != operator of *this and \a other
   *
-  * \sa class CwiseBinaryOp
+  * \warning this performs an exact comparison, which is generally a bad idea with floating-point types.
+  * In order to check for equality between two vectors or matrices with floating-point coefficients, it is
+  * generally a far better idea to use a fuzzy comparison as provided by MatrixBase::isApprox() and
+  * MatrixBase::isMuchSmallerThan().
+  *
+  * Example: \include Cwise_not_equal.cpp
+  * Output: \verbinclude Cwise_not_equal.out
+  *
+  * \sa MatrixBase::all(), MatrixBase::any(), MatrixBase::isApprox(), MatrixBase::isMuchSmallerThan()
   */
 template<typename ExpressionType>
 template<typename OtherDerived>
@@ -213,7 +291,14 @@ Cwise<ExpressionType>::operator!=(const MatrixBase<OtherDerived> &other) const
 
 
 /** \array_module
-  * \returns an expression of \c *this with each coeff incremented by the constant \a scalar */
+  *
+  * \returns an expression of \c *this with each coeff incremented by the constant \a scalar
+  *
+  * Example: \include Cwise_plus.cpp
+  * Output: \verbinclude Cwise_plus.out
+  *
+  * \sa operator+=(), operator-()
+  */
 template<typename ExpressionType>
 inline const typename Cwise<ExpressionType>::ScalarAddReturnType
 Cwise<ExpressionType>::operator+(const Scalar& scalar) const
@@ -222,7 +307,14 @@ Cwise<ExpressionType>::operator+(const Scalar& scalar) const
 }
 
 /** \array_module
-  * \see operator+() */
+  *
+  * Adds the given \a scalar to each coeff of this expression.
+  *
+  * Example: \include Cwise_plus_equal.cpp
+  * Output: \verbinclude Cwise_plus_equal.out
+  *
+  * \sa operator+(), operator-=()
+  */
 template<typename ExpressionType>
 inline ExpressionType& Cwise<ExpressionType>::operator+=(const Scalar& scalar)
 {
@@ -230,7 +322,14 @@ inline ExpressionType& Cwise<ExpressionType>::operator+=(const Scalar& scalar)
 }
 
 /** \array_module
-  * \returns an expression of \c *this with each coeff decremented by the constant \a scalar */
+  *
+  * \returns an expression of \c *this with each coeff decremented by the constant \a scalar
+  *
+  * Example: \include Cwise_minus.cpp
+  * Output: \verbinclude Cwise_minus.out
+  *
+  * \sa operator+(), operator-=()
+  */
 template<typename ExpressionType>
 inline const typename Cwise<ExpressionType>::ScalarAddReturnType
 Cwise<ExpressionType>::operator-(const Scalar& scalar) const
@@ -239,7 +338,15 @@ Cwise<ExpressionType>::operator-(const Scalar& scalar) const
 }
 
 /** \array_module
-  * \see operator- */
+  *
+  * Substracts the given \a scalar from each coeff of this expression.
+  *
+  * Example: \include Cwise_minus_equal.cpp
+  * Output: \verbinclude Cwise_minus_equal.out
+  *
+  * \sa operator+=(), operator-()
+  */
+
 template<typename ExpressionType>
 inline ExpressionType& Cwise<ExpressionType>::operator-=(const Scalar& scalar)
 {