# Questions tagged [geometric-transform]

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### Setting the location of the origin within an image for AffineTransformation

This question is closely related to this one, but slightly different. I want to perform several AffineTransforms on an image (myImage). For example, here is a ...
61 views

### Geometric transform of a plot with legends and title

I'm doing a ternary phase diagram, so I want to plot it in a triangle and not in a square. If I'm doing the transformation with legends it doesn't work, but if I don't put legends it does work. Why ...
127 views

### How do you implement metric tensor in Mathematica?

I'm trying to follow several tutorials on metric tensors. One of the common exercises is a polar metric. I'm stuck trying to implement this in Mathematica. According to the derivation, the polar ...
129 views

### Transforming 2D points on to a regular grid or lattice

I have a set of points in 2D generated by doing a DimensionReduce on a list of colors: ...
51 views

### Apply non-linear transformation to graphics object

I would like to define some simple geometric primitives (e.g. points and lines) and see what happens when I transform them by a non-linear transformation (in my case $(x,y)\mapsto (\sqrt x,\sqrt y)$). ...
63 views

### Translate (and scale) AnatomyData in three-dimensions

I would like to create a Graphics3D entity consisting of a human eyeball and a complex figure defined elsewhere. (For a minimal working example, assume that the ...
53 views

### Difficulty Displaying an Untransformed and Transformed Graphics3D Object with Show

I would like to illustrate a sequence of translations and rotations relative to the initial coordinate system simultaneously with multiple views using Manipulate. I discovered that there are some ...
88 views

### LinearModelFit with Standardized data

I have a small data set of six points: ...
83 views

### Rotate a circle in 3D space with RotationTransform

This is related to my confusion over how to combine graphics objects and geometric objects: see Affine transformation of circular arc in 3D. Why does evaluating the ...
338 views

### Affine transformation of circular arc in 3D

Start with a quarter-circle of radius 1 centered at the origin and lying in the $xz$-plane: arc = ParametricPlot3D[{Cos[t], 0, Sin[t]}, {t, 0, π/2}] I want to ...
207 views

### Removing anomalous points from data

I have two sets of 2d-data points which can be transformed in each other by using a certain transformation function. The problem is that in both data sets there are points which do not have ...
86 views

### Transform a field with derivatives

Given a function of Cartesian coordinates $(x, y)$ in $g(x, y) = \frac{d}{dx}f(x, y)-y\frac{d}{dy}f(x, y)$, I want to transform this expression to polar coordinates $(r,\phi)$. I saw a solution using ...
58 views

### How is the error of FindGeometricTransform calculated? [duplicate]

This question has beeen asked here but was not answered. How is the returned error calculated? I cannot find any information about this in the documentation of ...
84 views

### Transforming a conic to it's standard form

Suppose a conic is given.I need to transform it to standard form.So i tried like this: ...
63 views

### Sequential 3D transformations

I have a function s[x,y,z] that assumes a reference of centered at the origin and pointed along the positive z axis. Given two points, I want to rotate and translate that function such that its center ...
96 views

### How to draw a “Y” shaped branch in Mathematica?

I want to draw a Y-shaped branch in Mathematica. I am trying to draw a line of length L. In step II, I want to translate to the ending point of the line. Then I want to rotate at an angle of 45 deg to ...
601 views

### Drawing the Pursuit curves

I was reading this post on Filling Space with Pursuit Polygons. I didn't really see where the filling was, but found it quite interesting. Then I saw these pursuit ...
100 views

### With equation of vector fields which are in cylindrical polar coordinates, how to plot 3-D vector field? [closed]

I have the equation of vector fields which are in cylindrical polar coordinates. How do I plot 3-D vector field? I never used Mathematica. Edit2: ...
84 views

### What algorithm is used by FindGeometricTransform? [closed]

Can anyone tell me how the operation FindGeometricTransform[pts1, pts2] works (I mean inside logic of the transformation function), or where can I find such an ...
137 views

### Eigenvalues not invariant after similarity transformation

I have two examples of matrices that undergo a similarity transformation: a random matrix, and an exclusion-process inspired matrix. The similarity transformation $\sigma$ is given by an $L \times L$ ...
129 views

### Computing angle of rotation and scaling factor directly from given transformation matrix

I have a simple 2D transformation matrix performing rotation combined with scaling \begin{bmatrix} 1 & 1 \\ -1 & 1 \end{bmatrix} Where the scalar $r$ is multiplied with \begin{...
226 views

### Rotating panels with GeometricTransformation

In the field of architecture, learning to manipulate geometry so comprehensively with Mathematica has been fun. However, I seem to have reached my limits with the following ...
957 views

### How to double (or triple) each element of equation?

x^2/3+y^2/9==1 (0.5x)^2/3+(0.5*y)^2/9==1 Looks at above two equation,I multiply 0.5 to each element of second equation,which means when plotting, each point ...
307 views

### rotate image around fixed point

How can I painlessly rotate a tiff image by some small angle around a point with specific coordinates? The image shouldn't be altered otherwise, it can be padded with zeros if necessary, and then ...
355 views

### How to transform general Ellipsoid into rotated axis-oriented one?

Recently, I discovered a long-standing bug in the rendering of Disk and Circle primitives after applying ...
212 views

### Why BoundingRegion does not work well?

Bug introduced in 8 or earlier and fixed in 12.0.0 The underlying bug is unstable and wrong rendering of Disk[] and Circle[] ...
313 views

### How to determine roll pitch and yaw/Euler angles from approximately orthogonal matrix?

I have a collection of rigid bodies, each comprising ~100 particles. Each body is defined by a list of points corresponding to the coordinates of its constituent particles. The rigid bodies are ...
52 views

### How to get explicit result of geometric transformation? [duplicate]

Seems like this simply rectangle rescale should work and return the exact coordinates of the transformed resulting rectangle (which should be ...
476 views

### Extracting data from analog screen photograph

I'm using an analog profilometer from the 1970s and need a way to digitize the data and the only way is through a photograph. I've searched but all I could find was how to extract data from computer ...
133 views

### Rotate a RegionPlot3D

I plotted a bunch of regions using RegionPlot3D, and would need to rotate them around an a vector {0,0,1} anchored at point {5,5,5}. I tried RotationTransform, Transformed Region, and changing ...
140 views

### Performing geometric transforms on 3D text inside a Graphics3D expression

I am trying to put some 3D text inside a 3D graphics. So far I find two ways to make 3D text. halirutan in "Rotating an image along a Möbius strip?") ...
156 views

### DiscretizeGraphics issues with transformations

I noticed DiscretizeGraphics does not work correctly with transformed Graphics such as ...
297 views

### Results of Rotate and Translate are not the same in 2D and 3D

I cannot understand why the same transformations in 2D and 3D do not give the similar results (flat join segment line). In 3D the segments are not joined. Please help! ...
135 views

### Transform a RegionFunction in ContourPlot3D

This is related to a previous question but now I would like to apply a geometric transformation to the region function first. (I am trying to paint a spot on a cylinder, where the spot is the region ...
171 views

### Extracting scaling factor and rotation angle from TransformationFunction

I have successfully transformed two 2D data sets (data1, data2) by using ...
113 views

### What does the alignment error returned from FindGeometricTransform measure?

FindGeometricTransform returns "the alignment error together with the transformation function." How is the alignment error computed? I ask because if you iterate <...
159 views

### Mathematica Module for Denavit-Hartenberg Parameters to Transformation Matrix

I need to write a Mathematica module to get a 4*4 transformation matrix given the Denavit-Hartenberg parameters of the manipulator. How do I go about it?
150 views

### Get CoordinateTransformData from TransformationFunction?

I can define a composite symbolic transformation as e.g. tf = RotationTransform[θ, {0, 0, 1}] @* TranslationTransform[{0, 0, 1}] which returns (in ...
314 views

### Apply a four-point transform crop to an image

I am attempting to straighten and crop an image by using Edge Detection. The original image looks like this. By using edge detection and finding the max and min values for the points regarding the ...
201 views

### BSpline: construct surface from enclosing contours

I'm aiming to construct 3D shape from profiles (typical archaeological drawing stuff: front, side and top profiles views). Through several operation, I now have BSpline curves, which should define ...
244 views

### Plot points shifted (a lot) in output and PNG export but not in PDF export

Bug introduced in 8 or earlier and fixed in 12.0.0 Consider the following code: ...
92 views

### Using RotationTransform and Table

I created a small animation, very simple of course, that works very well. ...
77 views

### Implementation of ShearingMatrix

How does Mathematica implement ShearingMatrix? In other words given the parameters $\theta$, $n$ and $v$, what is the formula behind it?
229 views

### Images and Linear Transformations

I was playing around with some of the Image processing commands like ImageRotate. I thought it would be fun to try and make up some basic linear transformation rules - starting in 2D and then going ...
614 views

### How to align a poster?

I'd like to crop and transform out the magazine cover so that it is rectangular. I read the docs for ImagePerspectiveTransformation, and here's where I got to. ...
178 views

MWE: ...
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### Application of the projection matrix: Removing perspective distortion

I know that there are many posts about image treatment, but I still have trouble with this little challegene. Baisically I want to remove the perspective distorsion form this image: (source: http://...
308 views

### Projecting a Graphics3D object onto a plane

I would like to project a 3-dimensional cone onto a plane and mark the intersection (which is an ellipse) with a line. I find cone2 by performing a transformation ...