Questions tagged [code-request]
Questions on finding existing Mathematica implementations or expertise to address a clearly stated problem.
531
questions
2
votes
1
answer
48
views
Solving multivariable equation after setting partial derivative to zero
I have a real-valued function of four variables, namely $L[\phi, m0, m1, m2]$. I am interested in taking the partial derivative $\partial_{\phi}L$ thereof and setting the partial derivative to zero, ...
3
votes
1
answer
97
views
Problem with calculation of Lyapunov exponent
The code given by Chris K for Lyapunov Exponent does not work and gives lot of errors for the dynamical system given in equation(2) of this paper
The dynamical equations:
...
8
votes
1
answer
478
views
Borromean rings [closed]
how can I plot the Borromean rings in Mathematica?
I am interested in the configuration showcased in figure.
1
vote
1
answer
82
views
How to plot a community structure with specific properties
This code generates a community structure where each community is shown with a different color. The same color is used for bars within a community and outgoing edges from that community. I would like ...
2
votes
1
answer
80
views
Alternative Representation for Energy Levels and Energy Level Density
I need to show the energy level density around the local maximum of this double-well potential. I can do it using the following:
...
5
votes
5
answers
209
views
How to color a selected set of variables in a ListPlot
This code:
...
4
votes
1
answer
147
views
Recognizing a Higher Percentage of Multiple Barcodes from an Image
I would like a path or way to find barcodes in an image and read more of them and ideally quicker (It is very slow for an image).
So, BarcodeRecognize[] already ...
3
votes
1
answer
89
views
Quickly processing long lists using SequencePosition
Overview
SequencePosition does exactly what I need; however, it seems to be very slow for long lists. Is there an input option that would allow it to process faster? Or, perhaps an alternative ...
5
votes
2
answers
154
views
How to combine two different datasets to create a unified dataset
I have two different datasets : dsDat1 and dsDat2:
...
7
votes
6
answers
544
views
How to identify intervals for each integer number
I have two lists:
...
9
votes
2
answers
1k
views
Can Mathematica perform logical reasoning?
The question goes like this:
Ms. Li has just moved into a new home and plans to buy several potted plants at once. Her thoughts are as follows:
Buy either Green Radish or Podocarpus.
Buy at least ...
1
vote
1
answer
56
views
Compressing a file's name string
I was working with files where each name records a lot of information about what is in its respective file and wanted to compress it a little bit. So I wanted to change it's 'base'.
And I noticed that ...
2
votes
2
answers
180
views
Why do image sizes shrink when printing multiple plots as a single object?
I searched the repository a lot and found no answer to the following question. My code below produces 4 plots as a group. Each plot has ImageSize->300. However, ...
6
votes
3
answers
414
views
Placing a single X and a single Y axis to a group of plots
I have the following 4 plots sharing a common X and Y axes. I place 4 plots in a grid of 2 by 2. I do not want to use separate X and Y-axis labels for each of them. Instead, I want to put a single X-...
1
vote
2
answers
65
views
Numerical search of two simultaneous equations for three unknowns
Given the following two equations with three unknowns $\eta_1, \eta_2$ and $\tau$:
$\frac{i e^{-i \phi/2}}{\sqrt{2}} = \cos(2 \tau - \eta_1 -\eta_2)\cos(\eta_1-\eta_2) - i\sin(2 \tau - \eta_1-\eta_2)\...
3
votes
2
answers
277
views
Reading what is inside DataStructure[]
In my code I end up with such data structures and I cannot see what is inside. Is there a command to open this type of data structure? I tried \\Normal but it does ...
7
votes
1
answer
281
views
How to condition all cells of a notebook to a specific SeedRandom?
Is there a way to fix SeedRandom[.] for an entire notebook? If I carry out many calculations using random numbers, I need to give a separate code ...
4
votes
1
answer
139
views
How to maximize over a set containing an isolated point?
How can I maximize a function F over a set composed by a compact set like [a, b], plus a single isolated point, like $[a, b] \cup \{p\}$?
I cannot code the isolated point part.
1
vote
2
answers
130
views
Shape of a boomerang
I want to create a physical pendulum in 2D with the shape of a boomerang. And first problem I met with was how to define a boomerang, so I could have a shape of it and use it to make my pendulum. Can ...
1
vote
1
answer
147
views
How can a directed network model be linked to Dataset[ ] for further computation?
REVISED Question:
My only request is to know how to monitor the evolution of {agentStates, steps} in simulateSlow[...] function. ...
2
votes
1
answer
72
views
Defining multivariable function from previous cell output
In the following, I would like to define a function $h(\theta, \beta, \alpha_1, \alpha_2)$. The function $h$ should be defined by the output of a previous function (which includes the partial ...
1
vote
0
answers
150
views
0
votes
1
answer
51
views
Making some powers of variables inside the function : $X * \alpha^{m} *\beta^{n} f[A[x,y]] \Rightarrow X f[\alpha^{m}\beta^{n} A[x,y]]$
Suppose I have a function of the form $ a_1 a_2 \cdots a_n b_1 \cdots b_m \cdots f[L[x,y]]$. I want to make some particular letters and their power inside the bracket.
i.e.,
I want the letter $\alpha,...
1
vote
2
answers
125
views
Normalized Coincident Detection Probability of Laguerre - Gaussian Modes
I am working on a paper in which a pump mode is passing through SPDC(Spontaneous Parametric Down conversion) is converted into two photons called as signal and idler. In which laguerre-Gaussian mode ...
2
votes
0
answers
60
views
Extracting tables from .pdf
Can we construct some automated method for extracting tables from pdfs?
I can get decently far by just copy and pasting its content and splitting at newlines but it would be great if it was possible ...
2
votes
1
answer
80
views
How to transform the regions in which a piecewise function are defined?
I have a function f[x,y,z] that has a piecewise definition, i.e., its values depends on the ranges of the arguments. Now suppose I have a coordinate transformation <...
0
votes
2
answers
176
views
Sorting a list of functions by exploiting the recursive structure
Given a list of functions list and a vector of arguments {t, a}:
...
3
votes
1
answer
554
views
How to simulate a directed acyclic graph?
My goal is to have a code to identify and estimate the regression models associated with a directed acyclic graph (DAG), which is obtained through the reduction of a given weighted, directed graph <...
9
votes
1
answer
374
views
How to replace graph communities with the associated bar charts?
The following code generates a community graph and a set of bar charts, each one of which corresponds to a community.
...
0
votes
0
answers
71
views
Finding the Complete Silhouette Area Formula given a Convex Polyhedron
Like always, I am probably over complicating this and there is a much simpler way to derive a general formula using built-in Mathematica functions, think about it differently, or a faster way to solve ...
0
votes
0
answers
63
views
How to create a customized layered community structure from a directed graph
This answer provides a code for scaling the sizes of communities. I like to make the presentation of the community structure given in this answer (by @kglr) a bit more informative and friendly by ...
4
votes
2
answers
182
views
1
vote
4
answers
309
views
How to observe transition pathway of a stochastic matrix?
Given a stochastic matrix, m, I like to observe the transition path converging to the limiting distribution.
...
2
votes
1
answer
193
views
Python Code to Mathematica for Classical Map of Kicked Top
I am trying to convert this Python code for Classical map of kicked top to Mathematica.
For a single trajectory, I am able to ...
3
votes
2
answers
206
views
How to Draw Rectangle Chart Using Three Layers of Data?
I have some data given at three levels:
...
3
votes
4
answers
353
views
How to use Callout in a directed graph with circular embedding?
Given the following code:
...
5
votes
7
answers
439
views
Selecting string elements from list by using strings from another list
Given two lists of string elements list1 and list2:
...
2
votes
1
answer
141
views
2
votes
1
answer
64
views
How to locate chart labels correctly?
Given
...
1
vote
1
answer
62
views
How to inverse matrix equations? [closed]
I've never used matematica before so still learning. I'm trying to show that two equations below are equal to one another. To do that, doing an inverse transformation from 3.5-3 to 3.5-4 would ...
2
votes
1
answer
137
views
Convert R code to Mathematica code of Poisson log-likelihood for the epidemic curve
I want to define a function that simulates the model for a given combination of parameters and calculates the Poisson log-likelihood for the epidemic curve of reported cases:
...
3
votes
1
answer
207
views
Improve performance of Linear Optimization
EDIT
I am reframing the question here by pulling out the relevant part about linear optimization, you can find the original question and the entire code down below.
I am trying to increase the ...
4
votes
4
answers
422
views
A simpler or more concise way to divide the boundary of a polygon into equal arc lengths?
I am really looking just for the least amount of code needed to do this but it is still readable.
Here is the same polygon but the border is respectively split up into 10, 20, and 30 points along the ...
2
votes
1
answer
98
views
Covering a rectangle with shapes/closed curves of equal area?
Motivation: We want to cover a rectangle using smaller, non-overlapping shapes with the same area: the difference between the total area of the shapes and the area of the rectangle should be zero or ...
1
vote
0
answers
78
views
How can I write the code for an inverse integral transform?
How can I code any type of integral transform with its inverse integral transform in Mathematica which gives the correct results and properties? Below is the example for Elzaki transform:
...
0
votes
0
answers
51
views
Way to download all attachments from yahoo.com
For a long time now I want to download the attachments from my yahoo.con mail, only the files, no text, but in batches, so MMA gets into my mail and downloads every attached file it finds in a folder.
...
1
vote
1
answer
70
views
How to represent a digraph in a 2D circle structure using NeighborhoodGraph[.]
This code works and delivers NeighborhooGraph[.] of a chosen vertex. The resulting graph is bit difficult to understand and therefore I like represent the same ...
4
votes
1
answer
120
views
Questioning Mathematica's Condition Representation: Strange Solution for Integer Variable
I have the following sequence:
$$f_n(x)=\left\{\begin{array}{cl}
1 & \text { if } 0 \leq x<\frac{1}{2} \\
1-(n+1)\left(x-\frac{1}{2}\right) & \text { if } \frac{1}{2} \leq x<\frac{1}{2}+\...
6
votes
2
answers
189
views
Listing all user-defined definitions used in a function call
Is it possible to obtain all user defined definitions (and attributes) that are used in the evaluation of certain command (or alternatively just their symbols which I could imagine being easier when ...
1
vote
0
answers
164
views
How to show the limit of two functions in a code approach zero?
I don't know how to shorten the program, the entire code is required to understand everything:
...