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2
votes
1answer
114 views

Finding area of intersection regions

I want to be able to find the area of the intersection between a hexagon and a slice. I have tried RegionMeasure or Area but I ...
2
votes
2answers
352 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 ...
1
vote
4answers
372 views

Equation for the line of intersection between two planes

I have two equations: 2x + y + z = 1 3x - 2y - z = 5 And I have calculated the answers on paper, which gave me $x = 1 + t$, $y = -1 + 5t$ and $z = -7t$. So my ...
17
votes
3answers
517 views

How to compute the boundary of a group of ellipse efficiently?

Update1 I discovered that the bountary of a series of ellipses consists of the following three parts Part (I): the first ellipse's effective black-segment; Part (II): the effective ...
2
votes
1answer
63 views

Partition a line around intersections

I've got a bunch of lines (ideally in a single Region) as well as a single new line, e.g.: ...
7
votes
0answers
83 views

RegionIntersection: Point or Line?

This may be a minor point, but I'm wondering why RegionIntersectionof the two rectangles below gives 3 Lines rather than 2 Lines and 1 Point. ...
1
vote
1answer
61 views

Fast way to compute intersection of equivalence classes

There is a set $S=\{1, 2, \dots, m\}$ and $n$ equivalence relations on the set: $a \sim_i b $, where $a,b \in S$, $i=1, \dots, n$. Now we define $a \sim b$ iff $ a \sim_i b$ $\forall i=1, \dots, n$. ...
1
vote
1answer
106 views
0
votes
1answer
70 views

How to define where a line intersects its reflection

It is relatively easy to be able to find where two parametric functions intersect each other, but how about when one is a function and the second is its reflection? In the example below is it possible ...
-1
votes
1answer
79 views

How to get the intersection of three different curves [closed]

There are two functions, f(x,y)=x + y^2 - 8; g(x,y)=-3 x^2 + y^2 - 5; How can I get the intersection of these two curves? And how about the intersection among f(x,y),g(x,y) and z=0? Thanks
4
votes
4answers
286 views

Show intersection points between a curve and a line [duplicate]

I'm pretty new to Mathematica. I'd like to show the intersection points in my graphic. These are my inputs: ...
1
vote
0answers
91 views

Intersection of two volumes [closed]

I would like to know the volume of the intersection of a cone and a cuboid : ...
5
votes
1answer
92 views

Intersection of a MeshRegion and InfinitePlane

The documentation says that RegionIntersection is not implemented for MeshRegion objects embedded in 3D. But I have one such region and would like to slice it with ...
5
votes
4answers
267 views

Finding intersection points of two graphics

I am drawing a curve from a list using: ...
2
votes
1answer
160 views

Intersecting cone surfaces

Given two cone surfaces with common vertex O in 3D: Given are: Coordinates of point O Vectors OP, OL (OL is height for the green cone), OR (height of the blue cone), OC I would like to know the ...
1
vote
1answer
144 views

Finding equilibria to a system of 3 ODEs with 11 unknown parameters. Looking for the intersection of 3 surfaces

I have the following system of 3 ODEs of 3 variables $(\ell,M,h)$ and 11 parameters $(\sigma_{\ell},\mu_{\ell},d_{\ell},\sigma_M,\alpha_1,\beta,\alpha_2,\nu_M,\sigma_h,\nu_h,d_h)$: $\frac{d\ell}{...
7
votes
4answers
653 views

How do you find the self-intersection points of a single parametric trigonometric function? [duplicate]

How do you use Solve or FindRoot or other Mathematica functions to find the points at which the graph of ${\bf a}(t) = 3 \cos (3....
2
votes
1answer
72 views

RegionIntersection of a scaled cone? (elliptical cone)

I can generate the intersection of a line and a cone (from the example in the documentation). Is there a simple way to do the same for a line and an elliptical cone? i.e., this works: ...
2
votes
0answers
197 views

Intersecting RegionPlots [closed]

Does the Mathematica graphics system have any concept of intersecting regionplots? I've found about intersecting graphics but not regionplots so far. For example, if I want to show the intersection of ...
1
vote
2answers
91 views

How to find the same number in sublists of list

Intersection[Table[Table[Sqrt[p1]/r1,{r1,0.1,0.7,0.1}],{p1,0.5,5,0.5}]] I am trying to find same numbers in the sublists. But Intersection is not working for this....
2
votes
2answers
205 views
0
votes
0answers
41 views

Finding intersection of two infinitely long lines using points [duplicate]

EDITED In the Find intersection of pairs of straight lines problem, it is assumed that line are intersected by default and the purpose is to find the intersection points. In the present problem, two ...
9
votes
2answers
138 views

Finding self-intersections of a closed curve represented by an interpolation function

I've been trying to find particular simple closed curves on a plane. ...
10
votes
1answer
276 views

How to solve for the intersection points of two ellipses?

I have a parametric equation of two ellipses as follow $\begin{cases} x=a_1 \text{sin$\theta $}+b_1 \text{cos$\theta $}+c_1 \\ y=d_1 \text{sin$\theta $}+e_1 \text{cos$\theta $}+f_1 \\ \end{cases}...
1
vote
3answers
192 views

Plotting 3D Intersections

I'm trying to plot the intersections of four spheres. I've got the spheres plotted using: ...
1
vote
3answers
138 views

Getting a list of x coordinates of intersection points of two functions

I have two functions, f[x_] := 5 Sin[2 x] g[x_] := (5 x + 2)/(x + 2) I am trying to find the x coordinates that intersect ...
1
vote
2answers
432 views

Problems finding intersection points between line and generic function

I'm trying to find Intersection points between a line, which is given by 2 points, and a generic function (I want it to be able to handle polynomial functions, circles/ovals, lines and all ...
0
votes
1answer
90 views

How to create a line due to requiriements?

Considering we have three lines, and know the intersection points (How to find intersection points of lines?) How can I draw a line that will cross the intersection point of the two lines and will be ...
3
votes
1answer
161 views

Finding pairs where the intersection of them is empty set from a nested list

It would be better to give an example first. Suppose I have a nested list of the form list = {{ 1,2,3,6}, { 3,6,10,20}, { 4,7,11}, { 10,20}}; where each element ...
3
votes
3answers
160 views

Get the complement date range

Suppose that I have a date range list drlist = {{"2015-01-01", "2015-01-05"}, {"2015-01-07", "2015-01-07"}, {"2015-01-12", "2015-01-23"}} ...
1
vote
3answers
238 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: ...
0
votes
1answer
134 views

Count intersections of two non-polynomial functions [duplicate]

I have two Bessel functions, and I need to be able to count the number of intersections if both functions are plotted dependent upon the same variable. I can use FindRoot or FindInstance to get one ...
1
vote
1answer
232 views

Basis for the intersection of vector spaces

The MuPAD Notebook Interface provides the linalg::intBasis function: http://www.mathworks.com/help/symbolic/mupad_ref/linalg-intbasis.html How can I get the same ...
5
votes
3answers
107 views

GraphIntersection Problem

I Have a problem when plotting 2 functions. I want to find out where the two graphs intersect eachother. That said, I want the coordinates (x, y) of the point. ...
1
vote
1answer
178 views

how to find the vector intersection in a collection of triangulated 3D points?

I'm trying to calculate the 3D point coordinates for the intersection of a vector with a plane. I have been using the following code to do this: ...
14
votes
4answers
622 views

Find intersecting rectangles groups

I've a list of rectangles in the form {index, {centerX, centerY}, {width, height}} I want to find intersecting rectangles list. I want to obtain a list on the ...
35
votes
6answers
2k views

Finding length of intersection of two surfaces

I would like to know how we find the length of the intersection of two surfaces. For instance, in the following example,a surface intersects with a plane: How do we find the length of intersection ...
6
votes
2answers
298 views

Intersection of lists of disjoint intervals

Here is my problem: I have two very large lists of intervals (stored as many couples in the form {{"start point", "end point"}, ..., {"start point", "end point"}), ...
2
votes
1answer
169 views

how to find intersection between a parametric trajectoy and a point

I'have a 2d-system of differential equations, analitycally solved, depending on a parameter. I know that, by continuity, there exist a minimum value of the parameter such that trajectory passes ...
19
votes
2answers
927 views

Difference (or intersection) of two convex polyhedra

I have two convex polyhedra stored in the following form: a set of vertices vertices = {{x1,y1,z1},...}, a set of faces, where each face is a convex polygon ...
20
votes
7answers
2k views

Find intersection of pairs of straight lines

I have a list of 24 points, in which two consecutive points (1st and 2nd, 3rd and 4th, …) are supposed to form a line: ...
8
votes
2answers
459 views

Finding all sets of elements with two common elements in a large dataset

I have a very large network of atoms ($\approx 10^6$ atoms) with fixed positions that resemble a cellular structure: I have two files including: fixed locations of each atom set of points which ...
1
vote
2answers
177 views

Finding intersection and graphing [duplicate]

1) How do I find the intersection of f[c_] := y^2 - 2 x^2 (x + 3) == c ((y + 1)^2 (y + 9) - x^2) between the plots of f[0] and f[2] I tried plugging-in numbers. ...
1
vote
2answers
161 views

Controlling what is plotted in a multi-curve plot

My question is on trying to cut off certain plots within a Plot with multiple expressions being plotted. I want to be able to stop the two dashed-line plots at ...
1
vote
1answer
282 views

Computing intersections between a large number of sets: doing it sequentially vs. sending everything to Intersection[…]

Say we want to compute the largest common subset among a very large number of sets $Q_i$. One option would be to simply run the command: ...
-6
votes
1answer
246 views

Poincaré section for 3BP

I try to plot the Poincaré section for the 3BP i use the following code that works very well: ...
1
vote
2answers
508 views

intersection between function and plane

I try to solve a ODE system of equations and i want to plot the intersection of the 3D solutions with a costant plane. To do this i use the follow code: ...
3
votes
1answer
223 views

Intersection does not take list of lists

The function Intersection takes a number of lists (sets) and finds their intersection. However, the precise input is ...
2
votes
1answer
417 views

Finding intersection of 3D lines

I want to find the intersection of 3D line. I want to detect the 3D light source position by intersecting 3D lines. ...