# Tag Info

Accepted

### Unreasonably large deviation in calculations of mean curvature in different algorithms

First of all remember that curvatures, being 2nd order values, can be really sensitive to even very small variations. Moreover, we are speaking about computing differential values in a discrete ...
• 176

### Elements on a triangle (FEM)

Carlos Felippa, in Chapter 24 of the class notes for his introductory FEM class, has an excellent discussion of the formulation of the quadratic, isoparametric triangle element. These notes do not ...
• 5,844
Accepted

### Billiard reflection inside a triangular mesh

Funnily enough, determining the relationship between a point and a triangle is a big part of the work I'm doing right now on supersonic panel methods (check out https://github.com/usuaero/MachLine). ...
• 64
Accepted

### Mesh decomposition using coordinate bisection

You can definitely use coordinate information to inform mesh partitioning, a brief sketch follows. Given some set of elements, you can form a point cloud of their centroids and then apply principal ...
• 4,604

### Node connectivity for regular structured meshes

Supposing that you enumerate first in $r$ and then in $z$, you have the following enumeration $$n_\text{node} = j n + i\, ,$$ assuming zero-indexing. It is a good exercise for you to deduce this ...
• 8,209
Accepted

### mesh dependence of numerical adjoint solution

The issue has been finally settled in https://arxiv.org/abs/2201.08128 https://arxiv.org/abs/2201.08129 It turns out that there is a singularity of the analytic adjoint solution at the wall, which ...
• 51
Accepted

### Gmsh: what is the right syntax to iterate over a list of numbers with a For loop on the native language?

It seems for-loops in gmsh are made for consecutive numbering only, so I would define an array to map from consecutive index numbers to arbitrary entity numbers. ...
Accepted

### Min supporting line of a set of points

Given a set of $n$ points $\mathcal{P}$ in the 2-dimensional plane, consider the convex hull $\text{chull}(\mathcal{P}) = p_1 p_2 \dots p_h p_1$, with the boundary represented as a cycle comprised of \$...
• 3,788
1 vote

### GMSH: How can I extrude a surface in a non-linear way?

As a general suggestion: you can use CAD software (such as FreeCAD) when your geometry starts to get more complex. Gmsh has some CAD capabilities but its main purpose is to create meshes from CAD ...
• 8,209

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