All Questions

0
votes
0answers
50 views

Ideas for NDSolve?

I'm currently trying to find a numerical solution to a differential equation of the form: D[W[X], {X, 4}] ==(-(1/(delta + G - (G X)/L)^2) + 1/(delta + (G X)/L)^2) ...
7
votes
1answer
655 views

Is Mathematica really getting this limit wrong?

I'm trying to calculate: $$ \lim_{\beta \to \infty} \tanh \left( \beta A \right) = \mathrm{sgn} \left( A \right) $$ for $A \in \mathbb{R}$, $\mathrm{sgn} \left( \# \right)$ being the sign function. ...
0
votes
1answer
111 views

statistical database calculation [closed]

Assume a database with 10,000 elements of data is queried, through a statistical interface, for the average data value. The response is determined using the random-sample query method, with a subset ...
9
votes
0answers
219 views

Strange filling

I observed some strange behaviour when plotting a function with filling. The code is as follows: ...
1
vote
1answer
64 views

Compose two special power series expansions

I have two functions $A(x), B(x)$, given in a special power series form: $A(x)=1-x^{2}\left(\frac{a}{10}-\sum_{k=1}^{9}b_{k}\left(\frac{(x^{2}-1)}{r}\right)^{k}\right)$ ...
3
votes
0answers
49 views

What are good/best practices to take the Fourier transform of an InterpolatingFunction?

I have a function which I have obtained from numerical integration of a differential equation, and I would like to take its Fourier transform. What are good practices for doing this? To make things ...
1
vote
2answers
205 views

Plotting bipartite graph from adjacency matrix

I have an $m\times n$ matrix $A$ representing the adjacencies between the nodes of a bipartite graph. Specifically, the nodes are arranged in two partitions, of $m$ and $n$ nodes respectively, such ...
0
votes
1answer
84 views

NSolve cannot find the solution

I have some data which looks like: ...
0
votes
1answer
68 views

How to Manipulate a ListLinePlot[Transpose[{T,B}]] if T is a Table and B is a list of minima built by using FindMinimum?

I need to Manipulate a ListLinePlot using a parameter P. The problem is that this Curve is a ListLinePlot of a Transpose[{T,B}], in which T is a normal table and B is a list of minima got using ...
0
votes
1answer
39 views

NSolve stalls when given an equation containing Log

Why does NSolve not work for this type of equation? ...
3
votes
3answers
125 views

EdgeRenderingFunction on a Graph plot

This is my code, I want each line leaving a vertex to be the same colour from that vertex. So there should be 5 different coloured lines one colour for each vertex. ...
5
votes
2answers
138 views

What are the Method options Solve command accepts?

What are the Method options Solve command accepts? Solve has the Method option, however documentation contains no methods that it accepts...
0
votes
1answer
107 views

ListDensityPlot with discrete bins [duplicate]

We consider a table of the form data = Flatten[Table[{i,j,f[i,j]},{i,1,ni},{j,1,nj}],1] The function f[i_,j_] has been made ...
3
votes
1answer
115 views

Do not understand expression returned by FullSimplify

Why Mathematica returns (sec x)^2? (Tan[x]^2 + 1 - Sec[x]^2)/(Sin[x]^2 + Cos[x]^2 - 1) // FullSimplify Sec[x]^2 Because ...
5
votes
2answers
128 views

Fractions formatting in Column / Grid

Fractions are squished in GridBox: ...
1
vote
0answers
39 views

Finding simpler implied formulas while preserving contradiction

I have two Presburger formulas A and B such that A∧B≡False. From these I need to find "simpler" formula A′ (as simple as I can make it) such that A→A′ and A′∧B≡False. Is there any simple way to ...
0
votes
0answers
77 views

CleanSlate[] not working?

...
2
votes
0answers
98 views

A math function similar to “LatticeReduce” for finding linear independent basis

We would like to ask a math function similar to "LatticeReduce" for finding linear independent basis. The input is a list of vectors $M=\{v_1,v_2,v_3,\dots\}$, with the following property: There is a ...
1
vote
0answers
43 views

Why is `Cell` > `Convert To` > `InputForm` not invertible?

I sometimes post code to PhysicsSE, and I usually convert it to InputForm first before posting, in order to avoid pages and pages of ...
1
vote
1answer
152 views

Bilateral Laplace Transform in Mathematica (to be used with Moment Generating Functions)?

I am trying to solve a linear ODE for a Kolmogorov forward equation to get a stationary distribution of a random variable. The easiest approach may be to transform the ODE with a two-sided Laplace ...
0
votes
0answers
42 views

How to approximate a computationally expensive 5-dimensional manifold?

I have a 4-parameter family of functions, which I'll refer to as y[a, b, c, d][x]. In this notation, a, b, c, d are the 4 ...
1
vote
2answers
96 views

How to generate a unique file name similar as that created by CreateTemporary

CreateTemporary can generate a unique file name like ...
4
votes
4answers
216 views

Speed up replace all

I have large list of rules, I would like to use list/.rule, but assume that rule is a set of rules rule 1, rule2 rule...I want ...
0
votes
0answers
84 views

Problem with using the results of ParametricNDSolve in a ParametricPlot3D

I new to Mathematica and I have a problem with certain equations. I want to plot a trajectory in spherical coordinates given by the equations: ...
5
votes
1answer
382 views

How can we create a histogram distribution from binning data?

HistogramDistribution takes a list of data points, creates a histogram from them, and returns this histogram in a form that can be used as a distribution. I ...
1
vote
1answer
89 views

Unevaluated symbols [duplicate]

I often find it useful to define a symbol from strings (often in a loop in which I define other symbols). This I accomplish with Symbol (and often ...
1
vote
0answers
123 views

Solving Thue equations

A Thue equation is a 2-variable homogeneous integer polynomial of degree at least 3. It's well-known that such equations have only finitely many solutions over the integers. I'm trying to solve some ...
3
votes
1answer
124 views

plot Contourplot simple

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3
votes
2answers
523 views

Add coordinate axes to a 3D plot of concentric spheres

I want to add coordinate axis to a figure of nested spheres. I have the command. ...
5
votes
1answer
274 views

Preparing 2d plots for publication

When it comes to plotting a data my general attitude is to avoid post processing (say with adobe illustrator) as much as possible. To follow this strategy I would like to prepare publication-ready pdf ...
2
votes
4answers
195 views
5
votes
1answer
196 views

calling CUDA library functions

Mathematica has some predefined CUDA functions, like CUDAMap, CUDAFourier, etc. My question is how can one call functions which are part of CUDA library but not part of predefined Mathematica ...
0
votes
1answer
82 views

Symbolic integral including Hermite polynomial does not evaluate

I am trying to evaluate the following integral: Integrate[HermiteH[n, Sqrt[a]* x] * Exp[- (c/2)* (x^2 + y^2) + b* x * y - (a * x^2)/2], {x, - Infinity, Infinity}] ...
1
vote
1answer
88 views

Extending a grid to avoid line breaks in text

I was wondering what the best way is to extend the cells in a GraphicsGrid so that my text fits without line breaks. My problem is illustrated by the graphic ...
0
votes
1answer
354 views
0
votes
1answer
118 views

Height average between 4 points

I have a $3D$ space, if I had a square in this space: square = {{ 0, 0, 100}, { 100, 100, 50}, { 0, 100, 22}, { 100, 0, 86}}; how could I get the average height ...
0
votes
1answer
75 views

Strange behaviour of “Make Table” with exponential function

I am trying to create a simple interpolation of 1-Exp[-x^2] function, over the logarithmic grid, but I am stuck due to some unexpected behaviour: ...
0
votes
0answers
43 views

Can you tell (Full)Simplify to introduce a case distinction?

I got this term¹ as a partial result $\qquad\displaystyle T = -1 + (-1)^{\frac{1}{3} \cdot (1 - 2 n)} - (-1)^{\frac{2}{3} - \frac{4 n}{3}}$ which Mathematica refuses to (full)simplify further, even ...
2
votes
0answers
79 views

ParallelTable and expensive functions

I would like to build up a 2D-Table using ParallelTable as follows ...
17
votes
2answers
1k views

Drawing pairs (planar graph, circle packing)

Circle packing theorem states: For every connected simple planar graph G there is a circle packing in the plane whose intersection graph is (isomorphic to) G. How to use Mathematica to draw examples ...
2
votes
1answer
123 views

Why do identifiers of the form ${\tt c}k\$nnn$ appear in the rules returned by my function?

I want to define a function, PolynomialInterpolation to find the coefficients of a polynomial interpolation function. My trial is as shown below: ...
2
votes
2answers
131 views

Bessel derivatives

I tried to expand BesselJ[k,x] function into a Taylor series with Series command. Here both ...
4
votes
2answers
131 views

Listing all usage messages from a loaded package

I am writing several packages in collaboration with others. In order to help the group use my packages, I want to provide them with a simple reference of function names and usage messages. How can I ...
2
votes
1answer
79 views

Strange behavior using variable in Exists

I came across a behavior that doesn't make sense to me when I tried to use Exists in Reduce. If I run commands: ...
15
votes
4answers
1k views

How to implement the Observer design pattern?

As a programmer with a history with procedural languages, the Observer design pattern inmediately springs to my mind when attacking certain class of problems, mostly UI/notifications related. A ...
0
votes
1answer
63 views

How to take single item out of List? [duplicate]

I often get Lists that contain a single item, like {name} or {{2,3,4}}. Is there a function ...
0
votes
1answer
98 views

Dealing with nested lists

This question is strongly related to: Map and Apply a function on a nested list I am in a bit of a rut in terms of my MMA skills and looking to improve my coding. I've realized that rather than ...
0
votes
2answers
211 views

Plot “number of triples at each v in V(G)” [closed]

For a uni assignment, I need to plot the "number of triples at each v in V(G)". I tried to find relevant information in the Mathematica documentation through Google, but I'm lost. How do I get the set ...
2
votes
2answers
109 views

Extracting “records” from a matrix

From a rank 3 matrix like ...
2
votes
1answer
106 views

Display negative exponents always as fraction

I want Mathematica to display negative exponents always as fractions. I already tried: ...

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