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1answer
52 views

Astronomy: Transform coordinates from horizon to equatorial

I'm using Mathematica 10. Giving a longitude & latitude on Earth, giving a local time, how can I transform Horizon Coordinte (az , alt) to Equatorial Coordinate (RA , DEC). Use function so I can ...
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0answers
29 views

coordinate system problem

I had an issue about the coordinate system of mathematica. I have a {800,600} image acquired with a camera. The projection matrix P of the camera is calculated using the calibration task. Now, when I ...
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0answers
71 views

My code does not give the same results on mathematica 9 and 10

I have developed last year an algorithm using mathematica 9. In this algorithm, I remember that coordinate system of Image and Graphics are not the same. However, in mathematica 10 the coordinate ...
3
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2answers
140 views

Different between two graph in the Polar Plane

How can I plot $\theta=\cos r$ in polar plane? Of course I know that is different with $r=\cos \theta.$
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0answers
11 views

Change of co-ordinate frame [migrated]

Hi Can someone help me with this question. Say point P and u, v, w are three orthogonal-normalized vectors whose co-ordinate are: P = [Xp, Yp, Zp], u = [Xu, Yu, Zu], v = [Xv, Yv, Zv] and w = [Xw, Yw, ...
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0answers
67 views

What are the Mathematica functions to plot in a 3D version of elliptical coordiante system?

I am looking for the 3D version of elliptical coordiante system. My doubt is the 3rd coordinate. In elliptical, we have the ellipsoid and hyperbolic orthogonal system. IS there an equivalent in 3D? ...
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1answer
77 views

Plotting in Elliptical coordinate system

I want to plot an equation in elliptical coordinates. In the traditional elliptical system, Ellipse and hyperbola shares the same confocal point. Is there a plot function that draws a function in this ...
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1answer
46 views

CoordinateTransformData (cartesian to spherical)

I am using Mathematica v9.0.1.0 and wanted to compare Mathematica's CoordinateTransformData command to Matlab's cart2sph. (Note ...
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1answer
202 views

Compose many Geometric Transformations for 3D Graphics

I'm struggling to understand what would be a good way to compose several geometrical transformations to create a single TransformationFunction to be applied to a ...
0
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1answer
136 views

Order contour points in clockwise

I want to describe shape of an object using contour points descriptor. Given a silhouette (image black white of an object), I extrait the contour points using EdgeDetect[] fonction. After that, I need ...
7
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2answers
456 views

Find a right angled triangle

If I am given 10 points in the coordinate system in the for (x,y); where x is the x-coordinate and ...
-1
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1answer
81 views

Similarity of two plot to each other [closed]

I want get the similarity of two different plot by Percent ... I have many plots for comparison like below : y : ...
4
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1answer
68 views

Convert Locator (x,y) values to Lat/Lon as per GetCoordinates on Map

I want to convert the (x,y) coordinates you get from using a locator on a map to Lat/Lon coordinates - exactly like the GetCoordinates tool does when you right click on a map. ...
3
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0answers
103 views

Derivatives with respect to Cartesian coordinates of functions in spherical coordinates

This seems to me to be a common task, and the more surprised I was to not have found much on this. Suppose I have an expression f in spherical coordinates ...
8
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1answer
204 views

ImageTransformation: polar to cartesian

I am working on something that requires the polar transformation of some images. I implemented this transformation with ImageTransformation: ...
7
votes
2answers
392 views

Mapping data on Archimedes' spiral

I would like to map my data on Archimedes' spiral and preserve the distance between points on the curve. The test data consists of 20 evenly spaced {x,y} ...
1
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1answer
145 views

Using spherical derivatives with NDSolve

I am trying to plot the path of an object around a centre of mass. Obviously this needs spherical coordinates. The problem I encounter is with the derivatives. The Derivatives in spherical coordinates ...
2
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1answer
112 views

Plotting in projective space

I am having difficulty figuring out how to plot to projective space. Suppose I have a region which I have plotted such as: ...
0
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0answers
67 views

Geometric Transformation not working - degenerate points?

I've successfully used FindGeometricTransformation to project the simplex triangle onto the x-y plane: ...
1
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2answers
97 views

What is the 'Mathematica-way' to test a variable transform?

Hello Mathematica experts. I would like to play around with a simple variable transformation, to test some claims about it. I wonder if there is a Mathematica-like way to do this. The specific case ...
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0answers
100 views

How to construct a coordinate system that owns detailed calibration in the 3D enviroment?

Recently,I write a program to demonstrate the forward kinematics of the SCARA robot.The code showed as below: Using this function to construct the BigArm and ...
1
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2answers
314 views

How to make Mathematica use the chain rule?

Lets say I have the following PDE: $$x^2 u_{xx} - u_{yy} + u_y = 0$$ And I have the following change of variables: $$ s(x,y) = x e^y \, \, \, , \, \, t(x,y) = x e^{-y}$$ How can I use Mathematica ...
3
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1answer
217 views
0
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0answers
80 views

How to make MousePosition be referenced by a coordinate system established over an image?

In the question of How to make a curve selectable from a scaned image and convert it to a list of coordinates, thanks to the excellent answer of Alexei Boulbitch, I knew how to select a series of ...
2
votes
1answer
626 views

Time derivative of unit vector in spherical coordinates

Is it possible to take a time derivative of a vector given in some curvelinear coordinate system (i.e. spherical)? Mathematica would need to take into account the time dependence of the basis vectors. ...
1
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1answer
59 views

CoordinateTransformData that works for any dimension

The function CoordinateTransformData in Mathematica only works for three dimension. For example, ...
4
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1answer
222 views

Plot a cone in spherical co-ordinates

As we all know in spherical coordinates a function phi = π/3 gives us a cone. The cone makes an angle of π/3 with the imagined ...