Questions tagged [discretization]

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Discretisation of region intersection in 3D

If I try to discretise the intersection (BoundaryDiscretizeRegion), of a shell in a cuboid, some of the regions (that are found with RegionIntersection) are lost in the discretising process. I tried ...
73 views

Errors from NDSolve [closed]

I'm trying to solve a system of PDEs with periodic boundary conditions using NDSolve. This works if I don't specify an initial condition (but is uninteresting, ...
43 views

Is there a way to automatically use triangular elements in ToElementMesh [closed]

I have some simple code to generate a mesh over a rectangle. ...
46 views

Discretize Graphics3D with Scale and Rotate?

How can I discretize a Graphics3D object that makes use of Scale and Rotate? When I try <...
79 views

(Updated) How do I fix a Discretization error?

I am attempting to model a cross section problem from Calculus II using the general slicing method. Below is the working code to generate the "slices" of the defined problem; however, I would like to ...
218 views

Generating a grid such that the elements in each row add up to one

I'd like to generate a grid such that each element is a dimension $d$ vector ($\vec v$) of non negative components that add up to one. I could use the approach in this post and then choose among the ...
69 views

Perpendicular chord lengths from the boundary points of an arbitary 2D shape

Let's generate an arbitrary convex domain with smooth boundaries: Graphics[BSplineCurve[{{1, 4}, {5, 3}, {9, 4}, {5, 5}, {8, 7}}, SplineClosed -> True]] I'...
112 views

Randomly distributed circles inside an annulus

With the following code: ...
55 views

Creating Voronoi Mesh Region Bounded by Convex Hull (Possible problem with DiscretizeGraphics)

I want to create a MeshRegion that is VoronoiMesh bounded by the associated ConvexHullMesh. I followed the procedure in the answer for this post, but the resulting MeshRegion is very wrong. This is ...
47 views

How to get a “smoother” curve for a “discrete”-type curve?

A very interesting problem from here. I got the algebra in less than a minute with all 6 solutions (integers). But was puzzled a bit that the graph only gives 4. As now I have waken up and tried it ...
187 views

DiscretizeRegion was unable to discretize the region ImplicitRegion

I'm trying to model a 3D die with ImplicitRegion[] in order to find out its center of mass. However, when I apply ...
128 views

Converting 3D graphics primitives to 3D image data

My goal is to produce a 3D dataset, from a scene of simple transformed shapes. The idea is that this data serves as a ground truth for some tomographic reconstruction problems. (For this, it is ...
590 views

How to Discretize a Tube

In Is there a way to outline text?, I was amazed that BoundaryDiscretizeGraphics can discretize a Text primitive. So in a ...
186 views

using a custom method to discretize functions with 3 variables to be used in NDSolve

I was using the pdetoode function that @xzczd made: Dynamic Euler–Bernoulli beam equation But it only works for functions with 2 variables, I was wondering if it ...
91 views

DiscretizeGraphics on a RegionDifference not returning a MeshRegion

I want to take region difference of a sub-mesh of a Delaunay Mesh and a discretized ImplicitRegion. However, Mathematica does not recognize the return as a MeshRegion. Moreover, Discretizing the ...
156 views

Problem with ToBoundaryMesh

Bug introduced in 11.1.0 and fixed in 11.2.0 I have a problem that occurs in ToBoundaryMesh in Mathematica version 11.1, whereas in 11.0 it worked fine. I defined <...
77 views

Unexpected DiscretizeGraphics behaviour

One way to generate an annulus is by using ChartElementData: ...
169 views

Collision between a point and a square

Suppose we have a point of time laws: xP[t_] := 0.40 + 0.51 t; yP[t_] := 0.41 + 0.42 t; and a square with side: L := 2.01 ...
144 views

RegionPlot of DiscretizeRegion of ImplicitRegion

Writing: A = ImplicitRegion[Max[Abs[x - 1 + 2 y], Abs[y - 1 - 2 x]] == 1, {x, y}]; RegionPlot[DiscretizeRegion[A]] I get: while writing: ...
37 views

Loops and guesses

I have to solve a system of equations in the following way: I first guess a value for a variable, let's call it y, calculate another variable ...
239 views

How to discretize parametric curves for FEM analysis

I would like to know if there is anything available in order to discretize a 3D curve given by parametric equations in order to apply FEM analysis, e.g. to solve the wave equation on a thin wire ...
207 views

A simple way to discretize a linear region

I have a few hundred linear regions of dimensions 0, 1, 2 and 3 embedded in $R^3$ that I need to discretise. DiscretizeRegion does a good job with most of them, but ...
232 views

Discretize chart in a given interval

Using the following code: plot = Plot[Sin[x], {x, -Pi, Pi}]; points = Cases[plot // Normal, Line[{x__}] -> x, Infinity]; ListPlot[points] I get: Question: Is ...
91 views

Discretize a Graphics3D object over a given 3D lattice

Is there a way to discretize a Graphics3D object using a regular lattice with a given lattice spacing. For example: ...
98 views

Unexpected behavior of DiscretizeGraphics

As this code,we can visualize the "Test text" Graphics[Text[Style["Test text",20],{0,0}],Axes->True,AxesOrigin->{0,0}] I try to use ...
175 views

How to get a larger triangle when we discretize a sphere?

In order to solve this problem,I want to get larger triangles (Of course less amount). But I don't know how to do this. I have tried MaxCellMeasure and ...
205 views

Traverse “curve” on a grid from a given cell

I've got a binary grid which is mostly zero but contains a bunch of 1-cell wide lines (e.g. obtained from a ridge extraction). You can obtain an example input from the following line: ...
365 views

Why is DiscretizeGraphics missing points on my curve?

I have a graphics expression which renders nicely as a closed curve when put in Graphics, I don't understand why I can't get the lines from DiscretizeGraphics or ...
284 views

How to generate grid points on boundary of $[-1,1]^d$ for arbitrary dimension $d$ and specified resolution?

This must be a trivial thing, but I was not able to find a function for it in Mathematica. How do you efficiently create a grid with constant but specific resolution $r$ in all directions on the ...
81 views

Problems with sampling

Let $t\ge 0$ and let $f_{s}(t)$ be the sampled version of $f(t)$. If $$f(t)=\begin{cases}\int_{0}^{t}\exp\left(-\frac{1}{1-s^{2}}\right)\,ds,&|s|<1, \\ 0,&\text{otherwise}.\end{cases}$$ I ...
133 views

Issue with discretizing two arbitrary regions

Description This is in relation to this question. I am trying to derive this conical figure yet I seem to get an error with this code. I would be happy if someone could point out how to solve this ...
201 views

Beginner Simulating Gaussian Process with Correlation

I have no little experience with algorithms. I would like to learn how to simulate a real valued Gaussian process with correlation (e.g., exponentially correlated $\Gamma(t)=e^{-\vert t \vert/2}).$ ...
132 views

DiscretizeRegion fails for a triangular region

Bug introduced in 10.2.0 or earlier and fixed in 11.0.0 I define an implicit region like ...
353 views

How to apply DiscretizeGraphics to a tube? [duplicate]

I want to export the numerical solution of the Chan-Lee oscillator as an STL file so that I could print it out. But when I expanded the curve into a tube, ...
1k views

Finding NonlinearModelFit of multiple data sets with the same parameters and in two dimensions

I have multiple sets of data (between 3 and 6 depending on the cases) dependent of space, time, and some parameters. The data are the response of a harmonic oscillator under a non-trigonometrical ...
111 views

How to turn a Graphics primitive into a list of data?

I tried something small first, to get a feeling about this. So I defined a Rectangle[], placed it in a corner of ...