Hi Wolfgang, that is exactly the way how I tried to implement this. For a section of a sphere the approach of step-53 works perfectly well for my case too. But I need a full sphere. For the full sphere the problem is that SphericalManifold (like Manifold) does not have the a function called push_forward anymore. So I tried to overload the functions get_intermediate_point, get_new_point and get_new_points. I am not sure which member functions I need to overload if I derive my from class SphericalManifold. I am also not sure if I should derive my class from SphericalManifold or Manifold. It would be great if you could give some advice.
Best wishes, Sebastian Am Dienstag, 11. Juni 2019 17:39:44 UTC+2 schrieb Wolfgang Bangerth: > > On 6/11/19 1:06 AM, SebG wrote: > > > > actually I was not aware of this class. But this class is unfortunately > only > > implemented in 2D. I am not exactly looking for an ellipsoid but for a > sphere > > with a peturbed radius, where r = R * (1 + e * Y^m_n(\theta, \phi) ). > Here R > > is the reference radius, e > 0 is a scalar and Y^m_n is a real-valued > > spherical harmonic. > > > > To implement this, I thought that I could map a point from the perturbed > > sphere to the reference sphere. Then the updated point is computed on > the > > reference sphere and mapped back to the perturbed one. > > > > As a first step, I tried this approach based on the step-53 tutorial. > But I > > realized that closing the sphere at the poles and in azimuthal direction > does > > not work. Then I thought that it might easier to program the example of > an > > ellipsoid from this discussion. > > > > It would interessting to know why my approach of mapping back to a > reference > > sphere is not working with the updated version of SphericalManifold. But > maybe > > this is worth a new discussion. > > I don't know what the issue is, but the way I would write this is a > concatenation of two operations. The first would be the transformation > from > reference coordinates to the sphere (done by the push_forward() function > of > the SphericalManifold) and the second the scaling in radial direction > (done by > your own code). step-53 does this same kind of 2-step procedure, but > instead > of using the WGS84 transformation used there, you'd just defer to > SphericalManifold::push_forward. > > Best > W. > > > -- > ------------------------------------------------------------------------ > Wolfgang Bangerth email: [email protected] > <javascript:> > www: http://www.math.colostate.edu/~bangerth/ > > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/5d4bb9c2-d11c-4c4f-aaf9-035352f1c839%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
