Questions on the application of Mathematica to geometric problems. You might also consider adding the [graphics] tag, if appropriate.

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-5
votes
1answer
35 views

Calculating the top left corner in a 2d field [on hold]

Given I have a field with several rectangles like shown in the picture. A point with its x and y coordinates are given. The height(h) and the width(w) are also given. How can I calculate the top ...
1
vote
3answers
224 views

Only show part of a cube below an intersecting plane

I plot a cube and a plane. I just want to show the part below the plane. The code: ...
-2
votes
0answers
33 views

How to solve nonlinear system of four PDE

DSolve[{D[Subscript[g, 11][u, v, t], t] == -2 [Psi][u, v, t] Subscript[L, 11][u, v, t], D[Subscript[g, 22][u, v, t], t] == -2 [Psi][u, v, t] Subscript[L, 22][u, v, t], D[Subscript[L, ...
1
vote
2answers
106 views

How can I plot two concentric circles with a polygon inscribed in one and circumscribed about the other

So I am new to Mathematica still learning basic codes.. However I need help to become quicker in my research. Can anyone help me with the simplicit code to plot 2 concentric circles and a polygon of ...
0
votes
0answers
12 views

Find the shortest distance between the line x + 2y = 1 and the origin [migrated]

The question is as stated, find the shortest distance between the line x + 2y = 1 and the origin of coordinates
2
votes
2answers
326 views

Draw a circle through 4 points on parabola [closed]

I have two dynamic perpendicular parabolas: $y=ax^2+c, x=by^2+d$, which intersect in four points (the coefficients are chosen that way). There is a fact that we can construct a circle through these ...
0
votes
0answers
42 views

How can I plot 2 concentric fixed circles with a polygon inscribed in one and circumscribed about the 2nd

Can anyone help me with the simplicit code to plot 2 concentric circles and a polygon of sides n (that I can manipulate) inscribed in one circle and circumscribed about the other. However I want the ...
7
votes
1answer
215 views

Rigid Rotation of a Point Cloud

If I have a group of points that are aligned along some vector. For example: ...
2
votes
1answer
65 views

Plotting a manifold within an existing surface

I have a dynamical system $\textbf{x}'=\textbf{f(x)}$ where $x\in \mathbb{R}^4$. However, $x_1 +x_2 +x_3 + x_4 =1$ and $0\leq x_i \leq 1$ for $i = 1,2,3,4$, meaning the system lives on the ...
2
votes
1answer
270 views

Extract coefficients of differential form in package RGTC

I am using the Package RGTC to do some calculations in Supergravity. It allows to define differential forms after specifying a co-frame. I am working in with the 10d coordinates ...
1
vote
1answer
70 views
1
vote
2answers
57 views

Selecting points in list that are inside a contour [duplicate]

I have a list of points which form a closed (connected) contour or path in two dimensions. I would like to get all points from a second list which satisfy the requirement that they are inside the ...
2
votes
3answers
160 views

Distance from point to line [duplicate]

I'm a newbie with Mathematica and I managed to draw a line and a point in 3D on a graph ...
0
votes
0answers
43 views

Check if interpolated function passes through a specified region

Is there an efficient way to check if a curve that was obtained as an Interpolating Function (from solving differential equations numerically) passes through a given region? I am solving for two ...
-2
votes
0answers
14 views

how to calculate point after rotation [migrated]

I have basic square with width 36 (red) I'm rotating square by XYZ degrees ... in example there is 45 degrees black square is rotated by point 0,0 green square is rotated by center of sqare 18,18 ...
1
vote
0answers
56 views

Mirror image of a point about a line [migrated]

How can I calculate the mirrored position for a point in 2D space? I know the xy-coordinates of the two points which define the vector. I also know the coordinates for the yellow point which I want to ...
18
votes
5answers
466 views

Is there a numerical method/built-in to calculate the boundary of a set of graphs?

Recently, I encounted a geometry problem in my work. For a curve-family that owns the following parametric equation: $$E(t,\theta)= \begin{pmatrix} x_E(t,\theta) \\ y_E(t,\theta) \end{pmatrix}$$ ...
6
votes
1answer
262 views

Generating cylindrical geometry via extruding a section

Toady I want to build geometry as shown below: I know the Mathematica owns the built-in like Cylinder[], Sphere[] and so on, ...
35
votes
3answers
1k views

Can Mathematica solve Plateau's problem (finding a minimal surface with specified boundary)?

Given a closed curve $\mathcal C$ in three dimensions, is it possible to use Mathematica's built-in functionality to compute a minimal surface whose boundary is $\mathcal C$? For simplicity, let us ...
16
votes
0answers
168 views

Bug in RegionMember?

Bug persisting through 10.4.1 RegionMember (new in V10) appears to have a bug. For some polygons it finds points that are clearly outside to be "members" of the ...
10
votes
3answers
242 views

The envelope of a set of translated and rotated ellipses

I achieve a dynamic graphics by using Manipulate as follows: ...
5
votes
3answers
242 views

Assumptions for RotationMatrix

I'm making C++ program, and in my program I need a rotation matrix around any vector. I wanted to extract RotationMatrix[fi,{x,y,z}] output and put it in my ...
1
vote
1answer
86 views

Plot a line passing through two given points in 3D space

How can I plot straight line passing through two given points in 3D coordinates? For example, given the points M1: (2, -2, 0) and M2: (1, -3, -5) ...
2
votes
0answers
102 views

Plotting Seifert surfaces

Is it possible to make a Seifert surface in Mathematica, such as a Seifert surface for a trefoil knot? I was thinking of taking the parametrization equations for a trefoil knot and then somehow ...
7
votes
6answers
681 views

How to draw a dodecahedron with each face modified to a pentagram?

I'd like to draw a dodecahedron with each face carved on the sides so it becomes a pentagram. I wonder how to start to do this kind of task in the Wolfram Language? Edit: The result should still be ...
13
votes
5answers
1k views

To inscribe a circle in a given triangle

I am trying to to inscribe a circle in a given triangle but it isn't working. I've used GeoGebra with this construction and worked but as I'm new to Mathematica I am missing something. It can't be so ...
5
votes
4answers
1k views

An easier way to find the properties of an ellipse from its equation?

In this Q&A about fitting an ellipse to a set of points, there are multiple answers that generated general equations of the ellipse, like this one by @ubpdqn: However, the steps to find out the ...
4
votes
2answers
117 views

Arc length parameterization of a list of points?

Suppose I have a curve represented by a list of points in the form $\{\{x_0, y_0\}, \{x_1, y_1\}, ...\}$. How to generate a list of numbers $\{s_0, s_1, ...\}$ where $s_i$ is the distance of ith point ...
0
votes
1answer
69 views

Geodesic circle on a pseudosphere

I am trying to 3D print a portion of the pseudosphere, whose edge is geodesic circle. To do so, I plotted a region of the pseudosphere with the geodesics emanating from a point and I got this: The ...
-2
votes
3answers
113 views

Constructing an Equilateral Triangle Inscribed Inside a Circle

How to plot something like this? I need only the triangle and the 3 circles green. Thank you!
0
votes
3answers
37 views

A shift of a trapezoid and a connect to the original

I have: Graphics[{ Line[{{0, 0}, {30, 0}, {55, 50}, {-25, 50}, {0, 0}}] }] Now, I'd like to keep it in place, then shift a copy up and to the right, then ...
11
votes
1answer
142 views

How to make a two letter monogram in 3d like the one on www.mymo.is? [duplicate]

I want to achieve the same effect like the project on http://www.mymo.is/. By taking two letters and combine them in 3d, you can get a complex shape that looks like one letter on the one side and the ...
11
votes
4answers
2k views

Plotting an epicycloid

I am fairly new to Mathematica and I cannot figure out how to plot an epicycloid. I have plotted some neat looking things in my attempts, but can't make one. I am not looking to make an animation, ...
9
votes
1answer
761 views

Max & min distance between two moving points

I am trying to find the minimal and maximum distance between two moving points with Mathematica in an interval. For example, ...
8
votes
4answers
225 views

Probability of a random point inside the intersection of two triangles

I hope I can explain this problem clearly. It has been bothering me for sometime and I do not know how to solve it even with Mathematica's help. Right isosceles triangle E (the large red triangle) ...
4
votes
1answer
201 views

geodesics' on torus

Is it possible to draw geodesics between the points in a path on a torus - toroidal surface? geodesics: generalization of the notion of a "straight line" to "curved spaces" ...
0
votes
0answers
44 views

How to apply a shear matrix?

I have curves that I made to create a design using graphics[], and I wanted to apply a shear to this. I know/think that a shear comes in the {1,lambda}{0,1} form, and that I'm supposed to my multiply ...
42
votes
2answers
1k views

Numerically solving Helmholtz equation in 3D for arbitrary shapes

Context While studying manifold Learning I got interested in finding the eigenvectors of the Laplacian. (also in connection to this problem of solving the heat equation) Following this and that ...
3
votes
1answer
92 views

Angle between two vectors in spherical coordinates [closed]

I have two vectors: H = {1, 0, π/4}; EA = {1, 0, 0}; Which I want to be in {r, Phi, Theta} - which would should give an angle between the two vectors as ...
1
vote
1answer
123 views

Draw Vectors in Spherical Shell and then Animate

I want to draw three vectors inside a spherical shell. One of the vectors will be moving, the others will be stationary. However, the animation is the next step. For now, I would like to get the ...
2
votes
2answers
149 views

HIghlight intersection of two disks [duplicate]

I tried this: reg1 = Disk[{0, 0}, 1]; reg2 = Disk[{1, 0}, 1]; reg3 = RegionIntersection[reg1, reg2]; Then this: ...
1
vote
0answers
86 views

Intersection of two volumes

I would like to know the volume of the intersection of a cone and a cuboid : ...
15
votes
2answers
345 views

How to export textures?

Is there any object geometry format for which Mathematica supports the exporting of textures for external (non-Mathematica) use ? If not does anyone know of work arounds? All the texture primitives ...
3
votes
1answer
106 views

hippocrates moons for any shape

Can someone help me create code for a hippocrates moons on random shape with given amount of edges? I want to make something like this: when you press button, it asks you for the amount of ...
1
vote
0answers
78 views

Intersecting ellipsoids

First of all I know that findng whether two ellispoids intersect is complicated and there are specific algorithms created for this purpose (see, for instance, [1]. Actually, I am trying to follow this ...
22
votes
6answers
4k views

Drawing a square root spiral

Here is a start. I'm looking for a nice way to draw it. ...
2
votes
0answers
87 views

Wolfram alpha algorithm for geometric packing in 2D [closed]

Is there any way to gain access to the algorithm that wolfram alpha uses? More specifically, I want to pack small circles in hex and square patters in a larger cicle ...
7
votes
1answer
259 views

Unexpected behavior of GeometricTransformation

Bug introduced in 8.0 or earlier and persisting through 10.3 or later I have the following mapping on the complex plane: $$ z \mapsto \tau \mu z-1, $$ where $\mu$ is complex, $\tau$ is real ...
2
votes
2answers
184 views

intersecting cylinders

I try to replicate the two figures of two intersecting cylinders from here. I tried ...
2
votes
1answer
149 views

Surface Plot 3D of a strongly concave shape

I have a list of {x,y,z} points that all lie on the surface of an object (model output from COMSOL). I would like to generate a graphics object that reproduces the surface. Ideally, I would like ...