* newdvy = minor_mag * minor_unit_y = minor_mag * major_unit_x
*
* and use these tangent vectors as if they were the original ones.
- * This is usually a drastic change in the tangent vectors (even if
- * the singular values are not modified).
+ * Warning: Usually, this is a drastic change in the tangent vectors
+ * even if the singular values are not clamped.
*/
/*
* Discussion:
* V is an orthogonal matrix (that is, it represents a combination
* of a rotation and a reflexion). Consequently, V maps the unit
* circle to itself. For this reason, the exact value of V does not
- * affect the final ellipse, and we choose the identity matrix.
- * That is, we simply set
+ * affect the final ellipse. We consequently set V to be the
+ * identity matrix and set
*
* Jinv = U newSigma,
*
- * omitting the V^T factor altogether. Omitting the "V^T" factor
- * corresponds to moving from the SVD to the left polar
- * decomposition. In the end, we return the two diagonal entries of
- * newSigma together with the two columns of U, for a total of six
- * returned quantities.
+ * omitting the V^T factor altogether. In the end, we return the two
+ * diagonal entries of newSigma together with the two columns of U,
+ * for a total of six returned quantities.
*/
/*
* ClampUpAxes was written by Nicolas Robidoux and Chantal Racette
*
* The astrophysicist Craig DeForest pioneered the use of the SVD to
* clamp up the singular values of the Jacobian matrix of the
- * pullback transformation. It is implemented in his PDL::Transform
- * EWA code (PDL = Perl Data Language).
+ * pullback transformation for EWA resampling. It is implemented in
+ * his PDL::Transform code (PDL = Perl Data Language).
*/
const double a = dux;
const double b = duy;