Questions tagged [mesh]
Questions on the use and creation of meshes including the use of MeshRegion, ElementMesh, and TetGenLink.
689
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Is it possible to solve a differential equation with a user-defined variable mesh in NDSolve?
For some differential equations, its solution may evolve to a cusp, for example, singular behavior. One may want to introduce additional mesh points near the cusp to accurately follow the solution ...
- 33
8
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3
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325
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How to generate a mesh in an area with curves inside
I would like to know how to generate a mesh inside an area, and be able to find the original curve outline inside the area from the mesh.
For example:
There is a rectangle inside which there is a ...
- 83
4
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2
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151
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For "RegionPlot", how to fill lines, points, or grids in different areas?
For "RegionPlot", how to fill lines, points, or grids in different areas?
I have tried "Mesh", but it fills all region in same mesh.
I want to get the result just like this picture,...
- 41
8
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1
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Quarter a given triangular meshregion
For a given , examplary simple, triangular meshregion
...
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2
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How to do boolean operations between a large amount of regions
I want to do boolean operations between a large amount of regions.
For convenience, I consider a simplified problem.
The problem is as follows, digging out a large number of small hemispheres on the ...
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1
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84
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How to detect neighbours of a MeshRegion?
For a given triangle meshRegion(examplary) \[CapitalDelta]reg
...
- 36.4k
9
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2
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233
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Controlling the discretization of a Tube around a ParametricPlot3D
I am playing around with using Tube as an option under PlotStyle for a ParametricPlot3D ...
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1
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0
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49
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Problem with Mesh in Contour Plot
So I was using ContourPlot to plot an equation and I want to highlight the sampling points of the contour plot. So as written in the Mathematica documentation, I tried using ...
- 21
14
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2
answers
221
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Stretching a mesh
Imagine I want to stretch a mesh with a 'rubberband-type' effect. That is, upon and elastic stretch from both side edges, the mesh centres simply scale as follows
where the points are seeds for ...
- 4,138
4
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3
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154
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Mesh generation for a discrete set of points in ListContourPlot?
Given a (possibly disjoint) region, defined by a discrete set of points, how can I use ListContourPlot[] together with Mesh to ...
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1
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2
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81
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ArrayPlot3D mesh customization
I am trying to visualize a few 2D arrays in ArraryPlot3D. I think I have made it work, however, there is a minor detail on the mesh of the plot I want to improve.
For example, this is what the current ...
- 53
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4
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196
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How to order the coordinates generated by ToBoundaryMesh counterclockwise?
The following code works for polygons. A square 4x4 is tried here:
...
5
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1
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141
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How to combine several surfaces into a solid and compute its volume?
plot1 is taken from the BSplineSurface document. I add two Disk ...
- 231
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1
answer
88
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Coordinates of mesh generated by Mathematica-FEM
MeshCoordinates function yields more nodal coordinates than expected. Can I extract the coordinates of vertices only. Here is an example of a square region with a course mesh to explain the problem. I ...
3
votes
1
answer
82
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The element mesh has insufficient quality
I am quite new at FEM. I was trying to create a triangular mesh of a rectangular region. I wanted to do something very basic: Discretize the domain using squares and then subdivide each square into ...
- 117
0
votes
1
answer
71
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How to get mesh-information from `Plot3D`
In a simple example Plot3D shows a triangular mesh:
pic = Plot3D[Sin[x] Sin[y], {x, 0, 1}, {y, 0, 1}, Mesh -> All]
I know ...
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0
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1
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101
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2nd Order Regular Triangular Mesh on Rectangular domain
I want to create a mesh of 6 noded triangular elements ( 2 nd order element) on a rectangular domain as shown. (0,0) can be seen at left bottom corner with the whole mesh in the positive quadrant.
I ...
12
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1
answer
198
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Smooth refinement for a merged 2D mesh
Thanks to @user21 response and FEMAddOns I have been able to create a multi-region mesh. I am trying to make a smooth transitional mesh refinement with respect to a ...
- 1,554
3
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1
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104
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How to visualize an externally calculated FEM solution
I am trying to make animations of results of a FEM solver from an external model. Basically, I am pre- and post-processing in MMA. As a simple example, let's say I have a mesh such as:
...
- 1,554
3
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1
answer
83
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Finite Element Mesh generation with varying element order
I am trying to do a finiteElement Simulation of the Sun - Earth system for some modified gravity model in cylindrical coordinates. I find that 2nd order elements approximate the gravitational field ...
- 75
4
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2
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175
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Refine a quadrilateral mesh
I have created the following mesh for a slope stability problem:
...
- 2,760
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0
answers
29
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Meshgrid Visible in RegionPlot when Saving Figure as PDF [duplicate]
I have a region and a contour plot. My goal is to superimpose them to compare them. So, I used the Opacity[] on the region plot function but when I save the figure ...
- 367
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0
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69
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Error calculating RegionDifference of two disk sectors
I am trying to implement an exercise that should be straightforward. I have two sectors of disks (in blue and orange below) with an overlap. I am trying to calculate their Region Difference, but it ...
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1
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RegionIntersection for big mesh, AnatomyData["skin","MeshRegion"]
I want to cut a human in half.
Say skin=Entity["AnatomicalStructure","Skin"].
So, ...
- 2,648
3
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4
answers
252
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How can I create a mesh of closed shape?
I have this hexagon that defined according to these points
...
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6
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2
answers
113
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2
votes
1
answer
56
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Disappearing level curves on ParametricPlot3D
The mesh of level curves on ParametricPlot3D[] does not work for some functions.
For many functions it works normally, e.g.:
...
- 365
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0
answers
50
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TriangulateMesh failed at this kind mesh
mesh = ImageMesh@ImageResize[imgB, 512]
TriangulateMesh or DiscreteRegion failed at mesh,...
- 8,085
3
votes
1
answer
78
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FEM in 3D: assigning proper mesh for NDSolveValue
I am trying to compute electric potential in a simple 3D geometry containing (in a simplied version) 3 conductive rings (2 outer rings at 0 V, and the inner at 1 V) in different planes and I don't get ...
- 33
0
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0
answers
49
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Umbilic torus - Export to stl format produces bad mesh in MeshLab
I am interested to 3d print the following structure from this link. I assigned FaceForm and Thickness to check check for orientations and to give some thickness for printing. The resulting stl is ...
- 175
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2
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I need to make a Hexolnikov grid from a 2-D array AND in the row and column refer to the corresponding hexagon by painting over it
I'm new to mathematika. I need to access the hexagon by the index of the two-dimensional array that I set. This hexagon needs to be painted over, I was able to find how to set the grid only with a one-...
5
votes
1
answer
117
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Avoiding Concave Polygons
In a vertex model, vertices in a lattice are modelled by a set of ODEs. A T1 transition is the following: when a certain edge becomes small enough (given a threshold), two cells stop being connected, ...
- 4,138
7
votes
4
answers
619
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Problem with exporting RegionPlot as PDF
I have the following RegionPlot (which code I don't present since it comes from a long expression):
When I right click on it (within the notebook) and try to save ...
- 4,138
3
votes
1
answer
208
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3D FEM Mesh - Accessing values of individual boundary elements
I have 3D mesh and calculate the heat equation using NDSolve. I want to access the temperature values on the individual boundary elements to solve another problem (...
- 563
7
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1
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104
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FEM Mesh - how to get elements belonging to ElementMarker
I want to get a list of all boundary elements belonging to a certain ElementMarker of a boundary mesh.
This code creates a simple mesh and allows to inspect the <...
- 563
3
votes
1
answer
87
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FEM Meshrefinement for 1D Interval and Elements of order 2
I would like to create a 1D mesh of the intervall (-pi/2,pi/2) for solving a DE with FEM, with more elements close to +-1 - these elements should be of order 2, since order 1 elements yield too low ...
- 75
5
votes
1
answer
98
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3D FEM - How to use element markers for boundary integration
I am having trouble integrating over some curved boundaries and was thinking about using the element markers of the boundary mesh for integration rather than conditionals.
Is it possible to use ...
- 563
2
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0
answers
150
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NURBS model from a entire mesh
I have a mesh in STL file format and imported it into Mathematica.
data=Import["mesh.stl"];
or
...
- 29
2
votes
0
answers
95
views
Mesh Control Problem
I am having trouble combining two graphical objects. The problem has to do with controlling mesh lines. The simplest failing example is combining a circle graphics primitive with a RegionPlot. Either ...
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0
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79
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Custom mesh to help with a Fokker Planck eqn (refined rectangular mesh?)
Physicist here, new to SE and fairly new to MMA. I'm looking to solve a Brownian motion problem with inertia (m ≠ 0) and a velocity dependent diffusion coefficient, which in dimensionless units and ...
- 31
0
votes
0
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73
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Solving differential equation system with FEM when the equations depend on the mesh cell size
I am trying to implement Large eddy simulation with FEM for solving air flow simulation using Smagorinsky sub-grid stress model. In order to implement this there is a parameter (filter size) in the ...
- 9
5
votes
2
answers
234
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Modified Heat Transfer in Fluid Flow
I am trying to simulate Modified Heat Transfer in Fluid Flow (based on Buoyancy-Driven Flow in a Square Cavity ).
The modified heat transfer takes the form:
with the solid volume fraction:
The ...
- 1,624
8
votes
3
answers
304
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Smoother boundaries between components of segmented image
I'd like to use boundaries between components of a segmented image to create a mesh for finite elements, as described in Mesh for Images for three materials and meshes with multiple regions from 2D ...
- 1,110
1
vote
1
answer
55
views
Two figures in same graph, how to add mesh to figure 1 but not figure 2?
I plot two figures on the same graph. The following code adds mesh to both figures. But how do I add mesh to the first figure only (not to the second figure)?
...
- 39
8
votes
4
answers
646
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Mesh from Images for three materials
I want to mesh a figure which contains three different materials (organic-based materials and polymers) using Mathematica.
Namely:
Black color: material A
White color: material B
Grey color: material ...
- 91
2
votes
2
answers
214
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How to create a 2D mesh along a specified path?
I am trying to create a mesh along specific lines connecting specific points. Here I used Subdivide to create n steps along the ...
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2
votes
2
answers
117
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Parametric Plot: different coordinates for texture and mesh
I try to create a parametric plot which maps from the complex unit circle to a different region in the complex plane. That works fine but I have one problem:
I want to see the images of a mesh with ...
- 23
4
votes
1
answer
134
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How to create a 2D mesh and obtain all the coordinates and connectivity
I know this is a really amateur question, but I´m kind of new in here. Though I´ve been trying for the last few days I simply cannot convert a set of points (well actually a region) to a mesh. But ...
6
votes
1
answer
153
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3D FEM Mesh problem - either bad mesh or inaccurate geometry
I am having trouble obtaining a good 3D mesh. I have tried lots of stuff, either resulting in a bad mesh or inaccurate geometry.
My geometry consists of a cuboid with a quarter cylinder cut out on a ...
- 563
3
votes
1
answer
116
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Lighting/Mesh problem after GeometricTransform
This is probably a silly question but...
Context
I have gathered from this site Functions to draw sets of concentric 3D rings
as follows:
...
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