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

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1
vote
0answers
43 views

Change “ListPlot” to 16 bit accuracy? [closed]

I have (with the help of this forum) managed to plot a bifurcation diagram with the following code: ...
5
votes
3answers
286 views

How do I split a list of numbers to monotonic sequences?

Suppose I have: list = {1, 2, 4, 5, 7, 11, 8, 7, 3, 1, -3, -2, 6, 7, 80} And I want to split it to: ...
3
votes
2answers
322 views

Creating a bifurcation diagram of the logistics map [closed]

I am brand new to Mathematica so please keep that in mind. I've run into trouble trying to make a bifurcation diagram. Here is what I have done: I have a function $f(x)$ that relies on a value $r$ ...
-4
votes
0answers
79 views

Bifurcation diagram for delayed dynamical system [closed]

The delayed dynamical system describe as $\dot{x}(t)=y(t)-ax^3(t)+bx^2(t)-z(t-\tau)+I \\ \dot{y}(t)=c-dx^2(t)-y(t)\\ \dot{z}(t)=r[s(x(t)-e)-z(t)]$ where $a=1.0; b=3.0; c=1.0; d=5.0; r=0.006; s=4.0; ...
8
votes
1answer
145 views

How to construct the RHS of Wick's theorem

I've been trying this for a few days now, but I just can't seem to find an efficient (speed-wise) functional way to code the following task. Context: I would like to construct an expressions that is ...
1
vote
0answers
46 views

Different ways to program a recursive algorithm

Construct f (a numeric function) which takes multiple arguments with the following property: The single argument case $f(x_1)$ is meaningless, and the two-argument ...
-3
votes
1answer
78 views

How to implement Bifurcation of delayed Lorenz system? [closed]

The delayed Lorenz system is as follows: (Bifurcation parameter as $\tau$) $$\begin{align*} D^\alpha x_1(t) = & a_1(x_2(t-\tau)-x_1(t)) \\ D^\alpha x_2(t) = & a_2x_1(t)-x_2(t)-x_1(t)x_3(t) ...
2
votes
0answers
41 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
416 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
153 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
115 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 ...
3
votes
1answer
76 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
42 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
122 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: ...
4
votes
1answer
86 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 ...
3
votes
0answers
72 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
80 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
132 views

Error from NDSolve “Cannot find starting value for the variable”

I need help regarding this code. I have used NDSolve to find a solution. ...
1
vote
0answers
88 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
382 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
94 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
193 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 ...
2
votes
1answer
61 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): ...
12
votes
1answer
210 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 ...
2
votes
1answer
62 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 ...
1
vote
2answers
174 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 ...
4
votes
1answer
58 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 ...
3
votes
0answers
203 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
364 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) = ...
0
votes
1answer
49 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?
4
votes
1answer
363 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
208 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
194 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
137 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
76 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 ...
0
votes
1answer
126 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. ...
7
votes
3answers
438 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 ...
4
votes
1answer
98 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 ...
2
votes
1answer
217 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 ...
5
votes
2answers
874 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 ...
1
vote
2answers
160 views

A cone being intercepted by a slanted plane

I have the 3d cone: Plot3D[-Sqrt[x^2 + y^2], {x, -20, 20}, {y, -20, 20}, Mesh -> None, BoxRatios -> {1, 1, 1}] I need a slanted plane intersecting it. ...
1
vote
0answers
100 views

Implementation of Lubaehevsky-Stillinger Algorithm to pack hard spheres

To generate a model of a polycrystalline material with specified grain size distribution (e.g coming from a Monte Carlo Grain Growth simulation) the Paper "Effects of grain size distribution and ...
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 ...
4
votes
3answers
226 views

Code for (a,b) with gcd(a,b)=1?

I am trying to make a big table that includes all ordered pairs (a,b) with a (1,2) (1,3) (2,3) (1,4) (3,4) (1,5) (2,5) (3,5) (4,5) (1,6) (5,6) ... Any ideas? Thanks!
0
votes
2answers
63 views

How to stop code from evaluating same thing twice?

I have this code for evaluating some fractions: ...
0
votes
1answer
42 views

Output form of a result [closed]

Suppose I computed something with Mathematica, and the result is in the form Gamma[1 + N]^2 How can I tell Mathematica to write the result in a more ...
2
votes
1answer
214 views

How to make hollow Graphics3D?

I keep seeing a notebook to use of Mathematica as a 3D Printing tool (e.g.: this link). In the notebook on slide 8/11, we find these pictures: I'd like to design it as such that, but I don't ...
5
votes
4answers
208 views

Functional way to Climb an Association Decision Tree

Associations are nice tool to create decision trees. Here is a toy example of how I'm starting to use it: ...
2
votes
1answer
619 views

How to implement the directed Barabasi-Albert algorithm in Mathematica?

Does anyone know how to implement an efficient version of the [directed Barabasi-Albert algorithm][1] in Mathematica that scales until hundred of thousands nodes? The directed network mechanism is ...