Re: [eigen] Eigen appears to rock.

["Thomas Vaughan" <tevaughan@xxxxxxxxx>]

On Fri, Aug 22, 2008 at 7:09 AM, Gael Guennebaud
<gael.guennebaud@xxxxxxxxx> wrote:
>
> Thomas Vaughan wrote:
> >
> > > T.affine() is the 3x3 affine part of the above 4x4 matrix (it
> > > represents the rotation + scale + shear)
> >
> > This is a bit confusing because an affine transformation in general
> > combines a linear transformation and a translation.  Perhaps it
> > might be better to make "T*p" be equal to "T.linear()*p +
> > T.translation()", where "T.linear()" returns the appropriate 3x3
> > block of the 4x4 inside T.
>
> this change has been done ;)

I just checked anonymous svn.  All of the lower-case instances of
"affine" seem to have been replaced by "linear".  But how about
something like the attached diff for the rest?

-- 
Thomas E. Vaughan

There are only two kinds of people; those who accept dogma and know it,
and those who accept dogma and don't know it. - G.K. Chesterton

Index: Transform.h
===================================================================
--- Transform.h	(revision 850968)
+++ Transform.h	(working copy)
@@ -66,9 +66,9 @@
   /** type of the matrix used to represent the transformation */
   typedef Matrix<Scalar,HDim,HDim> MatrixType;
   /** type of the matrix used to represent the linear part of the transformation */
-  typedef Matrix<Scalar,Dim,Dim> AffineMatrixType;
+  typedef Matrix<Scalar,Dim,Dim> LinearMatrixType;
   /** type of read/write reference to the linear part of the transformation */
-  typedef Block<MatrixType,Dim,Dim> AffinePart;
+  typedef Block<MatrixType,Dim,Dim> LinearPart;
   /** type of a vector */
   typedef Matrix<Scalar,Dim,1> VectorType;
   /** type of a read/write reference to the translation part of the rotation */
@@ -111,9 +111,9 @@
   inline MatrixType& matrix() { return m_matrix; }
 
   /** \returns a read-only expression of the linear (linear) part of the transformation */
-  inline const AffinePart linear() const { return m_matrix.template block<Dim,Dim>(0,0); }
+  inline const LinearPart linear() const { return m_matrix.template block<Dim,Dim>(0,0); }
   /** \returns a writable expression of the linear (linear) part of the transformation */
-  inline AffinePart linear() { return m_matrix.template block<Dim,Dim>(0,0); }
+  inline LinearPart linear() { return m_matrix.template block<Dim,Dim>(0,0); }
 
   /** \returns a read-only expression of the translation vector of the transformation */
   inline const TranslationPart translation() const { return m_matrix.template block<Dim,1>(0,Dim); }
@@ -162,8 +162,8 @@
   Transform& shear(Scalar sx, Scalar sy);
   Transform& preshear(Scalar sx, Scalar sy);
 
-  AffineMatrixType extractRotation() const;
-  AffineMatrixType extractRotationNoShear() const;
+  LinearMatrixType extractRotation() const;
+  LinearMatrixType extractRotationNoShear() const;
 
   template<typename PositionDerived, typename OrientationType, typename ScaleDerived>
   Transform& fromPositionOrientationScale(const MatrixBase<PositionDerived> &position,
@@ -349,7 +349,7 @@
 Transform<Scalar,Dim>::preshear(Scalar sx, Scalar sy)
 {
   EIGEN_STATIC_ASSERT(int(Dim)==2, you_did_a_programming_error);
-  m_matrix.template block<Dim,HDim>(0,0) = AffineMatrixType(1, sx, sy, 1) * m_matrix.template block<Dim,HDim>(0,0);
+  m_matrix.template block<Dim,HDim>(0,0) = LinearMatrixType(1, sx, sy, 1) * m_matrix.template block<Dim,HDim>(0,0);
   return *this;
 }
 
@@ -357,7 +357,7 @@
   * \sa extractRotationNoShear(), class QR
   */
 template<typename Scalar, int Dim>
-typename Transform<Scalar,Dim>::AffineMatrixType
+typename Transform<Scalar,Dim>::LinearMatrixType
 Transform<Scalar,Dim>::extractRotation() const
 {
   return linear().qr().matrixQ();
@@ -368,7 +368,7 @@
   * \sa extractRotation()
   */
 template<typename Scalar, int Dim>
-typename Transform<Scalar,Dim>::AffineMatrixType
+typename Transform<Scalar,Dim>::LinearMatrixType
 Transform<Scalar,Dim>::extractRotationNoShear() const
 {
   return linear().cwise().abs2()
@@ -421,7 +421,7 @@
 {
   typedef typename Other::Scalar Scalar;
   typedef Transform<Scalar,Dim> TransformType;
-  typedef typename TransformType::AffinePart MatrixType;
+  typedef typename TransformType::LinearPart MatrixType;
   typedef const CwiseUnaryOp<
       ei_scalar_multiple_op<Scalar>,
       NestByValue<CwiseBinaryOp<