Questions on finding existing Mathematica implementations or expertise to address a clearly stated problem.

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1
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0answers
31 views

Changing from Cartesian to polar coordinates in partial differential equation [duplicate]

I have a partial differential equation: $$\left(x^2+y^2\right)\frac{{{\partial ^2}u(x,y)}}{{\partial {x^2}}} + x^2\frac{{{\partial ^2}u(x,y)}}{{\partial {y^2}}}=0$$ How to change from Cartesian to ...
7
votes
0answers
336 views

Problems when solving a nonlinear PDE system with NDSolve

The nonlinear PDE system is actually extracted from a research paper published in 2000 Here is the paper link The authors solved the system by using an ordinary differential equation integrator in ...
0
votes
1answer
131 views

How to write this Matlab code in Mathematica

I have a small hiccup here. I am trying to write my Matlab code for a dynamical system in Mathematica. I have managed to get most of it except one part. The Mathematica code for the system is ...
3
votes
0answers
98 views

Hopf Bifurcation for a non-linear dynamical system [closed]

I am very new to mathematica and also to Hopf bifurcation or any bifurcation for that matter. But I am trying to obtain a Hopf bifurcation for a dynamical system. Now, so far, I cannot find any ...
2
votes
1answer
52 views

How to create tickets on a Jira server using Mathematica?

Has anyone ever tried to use Atlassian's rest api from Mathematica? I'd love an example of a post request to create a ticket with specific properties. With cURL, it's easy: ...
1
vote
0answers
35 views

Coppersmith's algorithm like Pari's zncoppersmith?

Is there some Mathematica package (or built-in that I missed) available, more or less equivalent to Pari's zncoppersmith function? Paraphrasing that source: given ...
0
votes
0answers
43 views

how to use a tree as a key to construct a table of key values

I have an interesting problem that I was able to summarize in the form of trees, sets, and key value pairs. I have the following sets of keys and values \begin{equation} \begin{aligned} k_0 &= ...
2
votes
1answer
107 views

How do I make Mathematica show me the solutions that it has found while it is searching for them

How do I make Mathematica show me the solutions that it has found while it is searching for them, specifically in this: ...
5
votes
1answer
438 views

Linearized Einstein Equations with Mathematica

I need to compute the linearised Einstein Equations around a fixed metric $g_{\mu \nu}$ which is not the flat metric. Someone knows any Mathematica package or a review that can help me?
4
votes
0answers
122 views

Linearised Einstein equations

I need to compute the linearised Einstein Equations around a fixed metric $$g_{μν}=\text{Minkowski metric} + h_{μν}$$ which is not the flat metric. Does anyone know a Mathematica package or a ...
4
votes
1answer
77 views

Draw lines between all neighbours

I have seen this question, but what I want is a bit different. I have a set of data (blue points) and I would like to end up with something like this: , i.e. joining each site with all its ...
15
votes
3answers
1k views

How can this type of optical illusion be created in Mathematica?

I see these around the web and would like to make them in Mathematica. Combining them in an array is actually quite mesmerizing!
3
votes
0answers
56 views

Equilibrium solution to system of 4 ODEs with 6 parameters [closed]

I have the following system of 4 ODEs of 4 state variables $(M_{U},M_{R},F_{N},F_{M})$ and 6 parameters $(\alpha,b,\gamma,\mu_{M},\delta,\mu_{F})$ that I am trying to find the equilibrium solution ...
1
vote
2answers
71 views

Plot for pressure rise per wavelength [closed]

I have another question that i need to ask. I have been struggling in making the graphs for pressure rise per wavelenth. my equation for pressure rise per wavelength is: ...
0
votes
1answer
92 views
16
votes
6answers
3k views

3D surface that looks like a virus

I have been recently using Mathematica for composing animations that are part of the supplementary information of my papers. I am currently trying to build an animation that involves a viral ...
7
votes
1answer
387 views

How to create a Poincaré disk type kaleidoscope in Mathematica?

Creating a kaleidoscope in Mathematica is not a new topic at all, examples can be found from the links like Wolfram reference and Wolfram demonstrations. My question is how to create Poincaré disk ...
0
votes
1answer
102 views

Kronecker Delta and Contraction in Feyncalc

I am trying to simplify a rather complicated equation involving vectors and kronecker delta. I am trying to use Feyncalc for this purpose, but somehow i am not able to do it using Contract/Trick. ...
1
vote
0answers
84 views

Determining the order of continuity (smoothness) of a function

Is there any method to determine the order of continuity of a function (just like an interpolant) over a given domain, or at least determine the continuity on a given order? For example, according to ...
1
vote
2answers
279 views

Lyapunov exponent of a Henon map? [closed]

Can anyone help me with calculating Lyapunov exponent of 2D map, for example Henon map? If there is simple code, that would be great!
6
votes
1answer
83 views

How to delay the definition of a function from the time of package initialization to when it is first called

I am writing a package where a couple defined functions take a very long time define at initialization time (because they are large CompiledFunctions). However ...
1
vote
1answer
127 views

Import camera parameters and data from *.sif image files? [closed]

By default, Andor's line of scientific cameras saves data in an apparently undocumented *.sif format. Are there any Mathematica packages or code that can help import these data? I've inherited an ...
5
votes
0answers
125 views

Finding quasi-cliques

What is the best way to identify quasi-cliques in a graph in Mathematica? I don't think it has been implemented, so are there any solutions to do this? Or do I have to export the graph data somehow ...
3
votes
1answer
132 views

Solving a system of generated equations?

I would like to generate a function in the following form, where the number of terms can be specified arbitrarily: ...
2
votes
1answer
60 views

How do I center an item in a Grid?

I was trying to use Grid to align different plots, two on the first row, and only one in the second row, so I have something like this (where a,b and c are plots): ...
1
vote
2answers
170 views

intermediate steps of a Mathematica operation

How to make a multiplication or division, the intermediate steps. The numbers can be rational - decimals? it seems the OP merely wants Mathematica to show him how to multiply and divide the way ...
12
votes
1answer
169 views

Nearest Kronecker Product

Some people (see The ubiquitous Kronecker product by Van Loan) have worked on finding two matrices $\mathbf A$,$\mathbf B$ of specified size whose tensor product $\mathbf A\otimes\mathbf B$ is closest ...
3
votes
3answers
648 views

Sum over multiple indices

I would like to be able to enter the following left hand side of an identity. I can write the right hand side (i think) but am not sure about the left. The Left hand side is ...
2
votes
1answer
55 views

3D-Plot of a list of complex numbers and a list of real numbers

I'm a newcomer to Mathematica, and I'm having trouble with the following question. Say we have a list of complex numbers list1 and a list of real numbers ...
4
votes
1answer
95 views

Adding extinction factor to Monte Carlo analysis

I'm looking to add an absorption component to this Monte Carlo analysis, essentially I want there to be a 1% chance that a photon gets absorbed at each event as it travels through the medium, once the ...
4
votes
2answers
654 views

How to set up a simple Monte Carlo Simulation

there is a 1% chance that there will be a scattering event, if there is a scattering event the direction of scattering will be determined by a random sample of the custom[a_] function and if there is ...
29
votes
2answers
2k views

Playing with Matrix falling code in Mathematica

I was trying to create a Matrix falling code image with Mathematica. Here is my code: ...
5
votes
1answer
726 views

How to implement Kemeny-Young method? (rank aggregation problem)

Prehistory I am trying to make some statistical analysis of some experimental data, arises from measurements made ​​on an ordinal scale. I faced with the problem of rank aggregation: to get from ...
1
vote
1answer
478 views

Getting code from the Wolfram Demonstrations Projects [closed]

I saw from mathematica's website, there is a fantastic project about the 2D Riemann Sum. Riemann Sums For Functions of Two Variables I want to see the similar effect in my Mathematica (with ...
25
votes
2answers
2k views

How to build a bvh (a motion capture file format) player in Mathematica?

How to build a bvh player that can be used to visualize human motions in Mathematica? Any idea or sample code would be appreciated. ...
19
votes
3answers
2k views

Convert spectral distribution to RGB color

Presume I have a spectrum as a function of wavelength (an example being the blackbody spectrum): I want to convert that to a single RGB color to display on-screen, i.e. the "color" of that object ...
4
votes
3answers
735 views

Computing Gaussian curvature

Can Gaussian curvature $K$ be computed from WolframAlpha or any other available Mathematica program? Please indicate the program or its reference. If input ...
4
votes
1answer
57 views

How to canonically reorganize a list using only a limited set of manipulations?

I want to canonically reorganize (like Sort) a sequence of four objects seq[a,b,c,d], but the only manipulations allowed are ...
2
votes
0answers
173 views

adaptive histogram equalization

There is an interesting algorithm called contrast enhanced adaptive histogram equalization that does histogram equalization on small segments of an image (and then pastes them back together). I know ...
5
votes
1answer
317 views

How to program efficient undershoot/overshoot

I would like to solve the following boundary value problem for $y(x)$ for a fixed value of $k$ between $0 < k <1$: $$y'' + \frac{3}{x} y' - y + \frac{3}{2}y^2 - \frac{k}{2}y^3=0 \\ y'(0) = ...
7
votes
3answers
392 views

Calculating average distance between maxima

I'm having trouble figuring out a way to analyze some simple data. When graphed, the data I have make a somewhat sinusoidal curve. What I want to do is to find the x-values of the maximum peaks of the ...
0
votes
1answer
47 views

How to get the dynamic expression

$$Z_{n+1}=\frac{\alpha Z_n}{1+Z_{n-1}}$$ How to write the above expression in Mathematica? I want to get say Z_100, Z_10 by that scheme. Can I call say $Z_{10}$ if $Z_{n+1}$ is given?
50
votes
1answer
1k views

DumpsterDoofus's captivating generative art

How can I render these beautiful images that DumpsterDoofus posted?
4
votes
1answer
284 views

Lyapunov exponent plot

I am trying to create a Lyapunov exponent plot as a function of $\alpha$ for two functions: $$ f(x) = (\alpha + 1)x - \alpha x^{3} $$ and a piecewise function given by following Mathematica code: ...
2
votes
1answer
187 views

Bifurcation diagram for Piecewise function

At the moment I am trying to create a bifurcation diagram of the discontinuous piecewise function given by following Mathematica code: ...
0
votes
1answer
151 views

How do I find the nearest city out of a list of cities?

I am trying to find the next closest city to city 1 and want to use a certain radius to check what is the closest city I'm trying to create an algorithm for a TSP. Does anyone know how to implement ...
-1
votes
1answer
120 views

Trying to write my own Greedy/ Nearest Neighbor Algorithm

So I'm trying to write my own function and compare it to the results I have from using FindShortestTour. Does anyone know how to find the distance from each city to each of the others without ...
1
vote
1answer
71 views

How would I go about simulating conditional random birth 100 times?

So I have the following scenario: Assume you have this organism that reproduces by itself. An organism either reproduces 0, 1, 2, or 3 organisms at a time. Assume they're asexual and reproduce only ...
17
votes
2answers
769 views

How to perform fuzzy lookup between lists?

I have two big lists with 10,000 lines each, with product names from different databases. They have a lot of common products (50%), but they are not typed in the same way. For example there is one ...
2
votes
1answer
193 views

3D Vicsek Fractal Notebook

Can I get a link to a notebook that explores this fractal structure? I am specifically asking for a url to a Mathematica notebook that generates and / or visualizes this type of fractal. If that ...