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21
votes
3answers
891 views

RegionPlot3D in cylindrical or spherical coordinates?

RegionPlot3D is awesome. Unfortunately, it appears to work only for Cartesian coordinates. While there are ways to draw surfaces in spherical or cylindrical coordinates, I can't find a way to draw ...
10
votes
3answers
494 views

How to remove unwanted regions in a three-dimensional surface

As the title indicates, I want to delete some unwanted regions in a three-dimensional surface created using ContourPlot3D. Here is the corresponding code ...
9
votes
2answers
196 views

Controlling quality of discretized region meshes

I want to discretize 3D constructive solids, supported by Mathematica 10 regions functionality. Quality of resulting meshes must be controllable, and meshes must be useful for further computation. ...
9
votes
1answer
1k views

Using RegionFunction on multiple plots

I realize that the Plot function can plot multiple functions of x at the same time, using { }. I also know that the ...
8
votes
4answers
636 views

Showing a rectangular plot on an almost-closed sphere

I am currently teaching some students about the "point at infinity", and how it allows us to treat circles and lines as "the same", etc. I would like to kind of show this happening with a series of ...
7
votes
1answer
136 views

Strange behavior of `BoundaryMeshRegion`

BoundaryMeshRegion is new function of version 10. I am not familiar with the function. I want to decide whether a point is inside or outside in the Boundary using ...
7
votes
2answers
203 views

Union of plotted regions as sum of colors

I wish to plot 2 functions $f$ and $g$ so that the region bounded by $f$ has color $c_f$, the region bounded by $g$ has color $c_g$, and the region bounded by both has color $c_f+c_g$. E.g. $c_f$ is ...
7
votes
2answers
363 views

Ideas on how to improve the rendering of the letter B in this 3D region plot?

I have been playing with the RegionPlot3D idea from this question and have been trying to approximate the Gödel, Escher, Bach logo, but I am a little bit stuck on how to improve the rendering of the ...
6
votes
1answer
104 views

Can't plot rotated region

I was experimenting with the code from this question when I ran into another problem with regions. ...
4
votes
1answer
114 views

How can I prevent a Plot expression from evaluating points forbidden by its RegionFunction?

I just ran into this and it had me scratching my head for a good while. Say I have a function which may produce error messages for certain inputs, like e.g. ...
3
votes
3answers
120 views

Regarding how to use Reduce

Say for example I am doing the following in Mathematica ...
3
votes
2answers
571 views

RegionPlot3D contour problem

I have a little problem and didn't succeed trying to solve it on my own. Situation is, I need a visualization of the function $s - 3\cdot s\cdot q + q$ as a region on p == 0 if function's value is ...
3
votes
0answers
75 views

Precision problem while evaluating RegionMember or Element in V10

I'll try to give you a background on where the problem occured. The problem itself is defined near the end of the post. I'm running a sort of a simulation of a particle in a box. I finally got my ...
3
votes
0answers
226 views

Use of RegionFunction with Graphics3D?

I'd like to plot in 3D a long list of polygons created with TetGenConvexHull, but only in regions specified by a function. Is that possible? As I have it my ...
2
votes
4answers
408 views

Highlight integer points in RegionPlot

Is there any way to mark integer points after plotting region in Mathematica? For example, if I: ...
2
votes
1answer
128 views

How can I get dotted boundaries on a RegionPlot?

How do I plot something like $$\{(x,y): 1 \leq x^2 + y^2 < 9\}?$$ I want to be able to make the boundary $x^2 + y^2 = 9$ dotted line and the unit circle filled and coloured region in between? I ...
2
votes
0answers
73 views

Excluding region with `RegionDifference`

I can't make RegionDifference work for two Rectangle: ...
1
vote
1answer
126 views

Manipulate doesn't work for plotting a region where a matrix is positive semi-definite

I'm facing the following problem and would very much like you help. Thanks is advance! I have defined the following 4x4 matrix: \begin{equation} S=\left( \begin{array}{cccc} ...
1
vote
2answers
73 views

Unknown limit of an array of area integrals

Could someone explain why Mathematica can't finish computing this limit (this is a limit of an array, when n -> Infinity (n ...
1
vote
0answers
106 views

ListDensityPlot: How to only retain regions with data without using interpolation?

I'm working with ListDensityPlot on a set of triples, $\{\{x_1, y_1, z_1\}, \dots\}$. The data is on a semi-regular grid and looks just as it should through most of ...
0
votes
0answers
70 views

Parametric Plot not plotting all points

Basically I have a system of inequalities which I am solving and plotting using Mathematica. For example I have a system which has infinitely many solutions (it's unbounded). So I plot the system ...
0
votes
1answer
60 views

3D Contour Plot parts of sphere with gradient less than 0, equal to 0 and more than 0

I want to plot only parts of the sphere of radius 1 where the gradient $\frac{\partial z}{\partial x}$ is < 0, = 0 and > 0. The full sphere is given by: ...
0
votes
1answer
62 views

Integral over geometric region [duplicate]

I'd like to calculate this integral $$ \int_E y\ dydz $$ where $E = \{ (x,y,z) \in R^3 : z^2+6 < y^2 < 5z \}$ By hand i've got $\frac{1}{12}$ but i'm not sure, and i'd like to verify this ...
0
votes
0answers
48 views

How to judge if a point is in the interior of a closed curve or not? [duplicate]

For example: pts = {{0, 1}, {-(Sqrt[3]/2), -(1/2)}, {Sqrt[3]/2, -(1/2)}}; trig=JoinedCurve[Line[pts], CurveClosed -> True]; Then ...
-1
votes
3answers
130 views

Computing integral over explicit region [closed]

I need to integrate $f(x,y)=y^2-2x^2y+6x^3-3xy+2y-6x$ over $\{y\geq 2x^2-2, y\leq 3x\}$ Im using Boole in the following way; ...