some question about dfsu 3D

[lezhongwen]

Hello developers, this library has helped me solve a lot of problems recently, thank you for your contributions. I had some problems with reading and writing files.

1. The mesh data extracted from DFSU 3D files cannot be written to a mesh file, and i got ValueError: All elements must have 3 or 4 nodes. Element number 1 has 6 nodes.
2. After I wrote the regular mesh file(it can correspond to dfsu 2d) and the dataset extracted from DFSU 3D into a new DFSU file, the data became DFSU 2D. After checking, I found that not only the data quantity has decreased, but also the geometry attribute has changed.
   I would be grateful for your reply~

[jsmariegaard]

Hi @lezhongwen - I am now back from vacation and will have a look at these issues. Thanks for reporting!

[jsmariegaard]

To write the mesh from a dfsu3d, the following can be used:

 fn = "../tests/testdata/oresund_sigma_z.dfsu"
 dfs = mikeio.open(fn)
 dfs.to_mesh("oresund_sigma_z.mesh")

This should be equivalent to using to_mesh() method on the geometry, e.g. by

 ds = mikeio.read(fn)
 ds.geometry.to_mesh("oresund_sigma_z.mesh")   # will fail

But this was not possible forr dfsu3d - I am fixing this in #392.

[lezhongwen]

Thank you very much for your reply and contribution, and I am looking forward to the new version of Mikeio!!

[jsmariegaard]

@lezhongwen could you please elaborate on your 2nd point. I don't quite understand what you mean by "I found that not only the data quantity has decreased, but also the geometry attribute has changed" - could you please show an example?

[lezhongwen]

Dfsu3d should hold multiple layers of data in each grid of mesh. After I saved the data read from dfsu file with a mesh file(i am sure the mesh file can be matched with the data), I got a file with only one layer of data. And when the newly obtained file is read in, we can see its geometry attribute becomes dfSU2D.