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Questions tagged [4d]

4D involves calculations in four dimensions and typically relates to graphics programming. Use the [4d-database] tag for questions about the 4th Dimension database.

From Wikipedia, as of 5 March 2017‎:

In mathematics, four-dimensional ("4D") is a geometric space with four dimensions. It is typically meant to mean four-dimensional Euclidean space, generalizing the rules of three-dimensional Euclidean space. It has been studied by mathematicians and philosophers or over two centuries, both for its own interest and for the insights it offered mathematicians and related fields.

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How to plot 4D graph either in python or matlab?

I have two functions f and g. Both are dependent on three variables being x, y and z. The functions and boundaries of x, y and z are provided as follows: x = 150:5:250; y = 0.2:0.05:0.3; z = 1:0.1:2; f = 20./(x.^0.2) .* (y.^0.3) .* (z.^0.01); g = x…
Neeraj Bhanot
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Randomly select Elements of 4D matrix in Matlab

I have a 4D matrix with dimensions 7x4x24x10 (Lets call it main_mat). I want to get a matrix of size 7x4x24 (rand_mat) so that each element of this (rand_mat) matrix is actually a uniformly random draw from the main matrix (main_mat). I am sorry if…
AWAbid
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Plot and animate (x,y,z) position data of an object over time (t) in R

I'm trying to plot the position of an object in 3D space (x, y, and z co-ordinates) over time so that I can determine the path of the object. I'm finding it hard to visualise how this would work. I can plot the (x,y,z) coordinates in a 3D space, but…
Calvin
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interpolating 4D data

I have a set of GPS stations, whose coordinates I know (x,y,z), and for each station, I also have an error (e). These stations are of course unevenly spaced, otherwise it would be too easy. The thing is, in order to compute my error e for a station,…
Efferalgan
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Rotate normal vector onto axis plane in 4D

The problem I need to solve is to rotate a 4-simplex given in 4D on the hyperplane with normal vector (1, 1, 1, 1) so that I can draw it in 3D. For instance I need to know the rotation for the regular one having vertices e_i (that is the coordinate…
bog
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R applying a function to a sub-matrix

I have a large matrix roughly 90x100x90x200 The first 3 dimensions are spatial and the last is time. To apply a mask to my data, I wish to multiply the first 3 dimensions by the mask of the same dimensions for all 200 time points. Is there an…
user2530563
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Segmentation of 4D data on GPU

The problem im facing is segmenting large datasets (up to 2048x2048x40x10000 x,y,z,t == a few terrabytes decompressed, give or take). On the plus side, the features in this dataset are rather small; 20x20x20x20 max or so. As far as I can see, there…
Eelco Hoogendoorn
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4D plot display variables with data cursor Matlab

I am having trouble figuring out how display 4 variables in my plot. I want to vary the independent variables X,V, to produce the dependent variables Y and Z. Y is a function of X AND V. And Z is a function of Y AND X. This may be easier to see…
Tim
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Matlab: Plot3 not showing the 3rd axis

All the three variables I am using to plot are matrix of size 1x1x100. I am using this code line to plot: hold on; for i=1:100 plot3(R_L(:,:,i),N_Pc(:,:,i),CO2_molefraction_top_of_window(:,:,i),'o'); xlabel('R_L'); ylabel('N_P_c'); …
user238469
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Creating 4D Axes - Manim

I'm trying to achieve a way of showing 4d characteristics in manim. I would appreciate any way of showing a 4d axes and moving mobjects in a 4d way without coding the mathematics myself. is there a plugin for doing that?
GoodErnest64
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Read 4d .vol cine file from GE ultrasound

How do you view a 4d cine file(.vol kretz file format from GE).Can it be done using any libraries like VTK? Right now I have tried exporting the file to .vtk format using 3dSlicer and rendered it as a 3d volume. Are there any other ways to load the…
purrister
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Plotting 4D data as contours

I want to create layered contour plots using (x,y,z) coordinates and a fourth dimension, represented by color and intensity. Each layer-related data is in the CSV file (data) with lat, lon, levels, and dust_mixing_ratio columns. How to create and…
shravani banerjee
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4D contour plot using .nc file

I am trying to plot a 4D surface plot from netcdf data which has 4 dimensions: time, lat, long, and lev for 5 variables (DU001, DU002...005) (sample data). I have to plot the first variable DU001 vs lat, long, and levels (72 levels) such that the…
shravani banerjee
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4D surface plot from NetCDF data

I am trying to plot a 4D surface plot of netcdf data (attached file). It has 4 dimensions: lat, long, lev, and the value-dust mixing ratio (5 values DU01, DU02...05). As I am very much new to Python, I don't know about it much. I have to plot DU01…
shravani banerjee
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4D Tensor Multiplication with Tensorflow

I have a Tensor A with the shape: [1000,24,24,2] and I want to multiply it with its transpose so that I can get C = A^T.A I tried: B=tf.transpose(A) C = tf.matmul(B, A) and I get this error: InvalidArgumentError: {{function_node…
Diego Solis
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