Tagged Questions

Questions about functionality that defines or operates on regions (i.e., an open, connected set), including geometric, mesh-based, or data and formula-defined regions.

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RegionIntersection and area on GeoPosition polygons

I am trying to write a simple procedure to find the percentage of a large property falls in each surrounding ZIP code. A problem that I am encountering is the fact that RegionIntegration[] and Area[] ...
94 views

Why does RegionUnion fail for these Regions?

Bug introduced in V10.0 and persisting through 10.4.1. Introduction Lately, I asked for a solution to inflate and unite a List of BoundaryMeshRegions: Inflate ...
168 views

Intersection coordinates of two spheres

I am trying to obtain a list of coordinates at which two spheres intersect. Take for example the spheres: sp1=Sphere[{0, 0, 0}, 1] and ...
103 views

Is there a better way to produce a shape with exclusions in RegionPlot3D? [duplicate]

I'm attempting to create a certain shape. It's essentially a rectangular prism with an array of cylinders cut out of it, and then some half shells of cylinders along the sides. My attempt is basically ...
53 views

Intersection of volumes defined by inequalities

I have 5 inequalities with some parameters like dh, din and thetawhich I intend to vary. In ...
28 views

Why are there these jagged “shards” in my RegionPlot3D?

I'm creating a region out of two component regions. Before anyone suggests it (because a lot of similar questions are about it), I don't think the problem is increasing PlotPoints. I've increased it ...
71 views

Volume of a Region defined by Inequalities [duplicate]

I am trying to compute the volume of a 3-dimensional region defined by 5 inequalities. Mathematica takes too long to compute it. In fact, I haven't ever seen it complete the execution of the below ...
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How to plot the difference between two regions? [duplicate]

I'm trying to take the difference between two regions. In this case, one region is a cuboid, and the other is a cylinder. Here's what they look like drawn with Graphics3D: ...
139 views

Projection of a 4D region defined by function on 3D region

I am trying to project a 4D region defined by a function onto a 3D region so I could visualize it. I am trying to use Resolve to achieve this but it is not working. ...
28 views

Cannot avoid redundant function evaluations in RegionPlot

I am trying to use RegionPlot to visualize the regions where a function has different integer values. For example ...
67 views

Deleting circular regions from a larger Circle

I am trying to determine how the Dirichlet eigenvalues of the Laplacian of a circular region change. I would calculate the principal eigenvaluen of this image, and gradually decrease the radius of the ...
80 views

RegionPlot with rank constraint

I am trying to plot the feasible region of a rank constrained semidefinite program shown below: The Mathematica code that I am using is the following: ...
54 views

TransformedRegion and RegionPlot

I encountered an issue using RegionPlot together with rotated regions. Notice how as long as one drags a slider in this simple ...
103 views

RegionPlot Failing on my System

I am running Mathematica 10.4.1.0 on a MacBook Pro OSX 10.11.5. I opened the documentation for TransformedRegion, went to this example in Scope, Formula Regions. When I open this particular ...
133 views

Create a filled ListPlot, where the points in the list come from within the regions rather than from the region boundaries

Is it possible to fill, color, under the points in ListPlot where the points define the area and the boundary? Assuming that the number of points are large enough ...
214 views

RegionIntersection puzzle

I am using RegionIntersection[] to intersect two rectangles, phrased as Polygon[]s: ...
89 views

Selecting and plotting points belonging to a region from a random sample

I'm facing a problem with RandomReal when using ListPlot to plot some constrained points. I found that at every run of MA kernel ...
73 views

How-to derive conical region in an arbitrary geometry?

Description I have been working with derived geometric regions and ran into a problem when deriving RegionIntersection of a Cone...
59 views

Disobedient RegionPlot3D

I faced a strange behavior of a RegionPlot3D. I am drawing a piece of a plane bounded by a parabola. This works: ...
88 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, ...
80 views

Issue formulating RegionPlot3D to visualize RegionIntersection

Description I am looking to visualize gas cloud growth within custom modules. For demonstration purpose, it is assumed gas cloud takes a spherical shape whilst module is defined using a ...
63 views

RegionPlot error

I'm trying to represent the following table using the command regionplot. The rectangle (0,0), (0.5,0), (0,1),(0.5,1) should be covered, however it is not. Does anyone know what the problem is? Thank ...
120 views

The unexpected behavior of region calculate

In my this answer,I get some overlapped disk like this placed with red arrow point out But actually that function of diskMake is designed to produce ...
114 views

Find coordinate {x, y, z} where two functions are minimal

I am trying to find a point in a ListPointPlot where the total RegionDistance is minimal AND the total differences of the <...
269 views

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Why is MeshRegion atomic?

I wanted to make some changes inside a MeshRegion today and found that unlike Graphics objects, it can't be done directly ...
55 views

Region traced by the endpoints of all vectors given by a parametric expression [closed]

I have the expression of a vector e, with 3 parameters tt1 tt2 and tt3: ...
63 views

Minimize with Interval restriction

If for instance I have a problem of this sort: ...
129 views

RegionPlot with LogScale

I would like to have my RegionPlot with logarithmic scale in x and y. My code looks like ...
100 views

How to remove parts of a curve?

I have a curve that have some unwanted parts. How can I remove them ? Or how to constraint the curve to a specific region ? Here's a MWE that shows the problem : ...
132 views

1D ImplictRegion can not be plotted with RegionPlot

I am using Mathematica 10.4 In the documantion page of ImplicitRegion, there is an example ...
49 views

Simplify Expressions used to define Region

For example, RegionPlot[{x + y > 1, x - y > 1, y - x > 1, -x - y > 1}, {x, -2, 2}, {y, -2, 2}] can be somehow written as: ...
87 views

DiscretizeRegion does not include the boundary specified in ImplicitRegion (10.1)

I am trying to do some 3D PDE solving, and I keep running into problems with boundary conditions because my meshed boundaries are not what I expected. For example, the following code ...
73 views

DiscretizeRegion fails for a triangular region

I define an implicit region like R = ImplicitRegion[ 0 < Sin[u]/Cos[v] < 1 && 0 < Sin[v]/Cos[u] < 1, {{u, 0, 2}, {v, 0, 2}}] But when I ...
162 views

How to improve accuracy of NIntegrate over ImplicitRegion

I'm trying to compute the area of a implicit region given as ...
58 views

Confused about the behavior of the properties of Regions

Actually we can get some information in here.But I'm confuse this phenomenon still: test = ConvexHullMesh[RandomReal[1, {7, 2}]] ...
149 views

How to assign Element marker at boundary edges

How to assign marker at the boundary edges as 1, 2, 3, 4 respectively and set all of the inside elements of region as 0? for example: Code: ...
26 views

Problem with unbounded implicit region over integers

I have a region specified implicitly, and want to find the region bounds, however there are some problems when the region is defined over the integers and it is an unbounded region. This unbounded ...
203 views

How to create a surface mesh embedded in 3D?

I am working on a problem where I want to optimize current densities on 2D surfaces embedded in 3D to generate magnetic fields. The current density on a surface can be written as a scalar function ...
38 views

Can I convert a 2D Region embedded in 3D into a 3D region, filling in the shell? [duplicate]

Here's a simple example, where there are built-in functions to describe both objects. {shell, ball} = DiscretizeGraphics /@ {Sphere[], Ball[]} The first of ...
98 views

What is a robust way to determine if two polygons overlap? Possible bug in RegionIntersection or Area

When trying to determine if two polygon objects overlap, I think the intuitive way to do this would be to use the RegionIntersection function to find the ...
94 views

How to color the exterior of a region in a RegionPlot?

One can color the interior of a region by ColorFunction. But how to color the exterior of a region of a RegionPlot (I want to ...
164 views

RegionNearest and neighborhoods

In this previous question we see that RegionNearest isn't quite as 'capable' as Nearest for some things. Similarly, I need to ...