All Questions

-1
votes
2answers
133 views

How to get a peek at the source code for demonstrations if there is no source code provided [on hold]

NOTE: The prequel to my question has been answered before here In the case of the question linked above, the author's code was available. But I would like to know if it is possible to reveal the code ...
2
votes
1answer
117 views

Einstein summation convention for symbolic vector calculus

I am trying to do some vector calculus in Mathematica in index notation form because it gives a clear result that can be compared to pen and paper calculations. Since there is no built in Einstein ...
3
votes
2answers
62 views

Only display plot legends for curves that are visible in the plot range

I have a list of coefficients, i.e. coefficients = {{a1,a2},{b1,b2},...,{an,bn}} From this, I generate a list of functions. I then plot these functions with a ...
4
votes
2answers
44 views

Mathematica online: How to evaluate initialization cells (only)

I‘m sometimes (mainly on vacation) Mathematica online on an iPad. Up to now I could not find a way to evaluate the initialization cells (only) which is a menu command in Mathematica on my Mac. Does ...
0
votes
1answer
29 views

Suppressing the repeated evaluation of a sub-expression in a Manipulate expression

I'm trying to build CDF from a code that you can see on the image. However, it is painfully slow. The way to improve speed would be to reduce calculations. The same value is recalculated over and over ...
0
votes
1answer
33 views

Using TeXForm for subscripted variables

I tried following the answer in TeXForm and Symobilze, however, I have trouble making it work. I loaded the Notation packages and symbolized all expressions with a subscript as in the example. I ...
2
votes
5answers
133 views

Finding the location of a point in a given list

Say I have a list: ...
2
votes
1answer
29 views

Return multiple results from compiled function [duplicate]

I wrote a function with Compile that produces a large array of data and later does some computation on it. Now, I want to return from the compiled function not only ...
0
votes
0answers
21 views

Check Existence of context

When you accidentally load some packages that introduce contexts (like the notation package) twice you sometimes get errors involving shadowings etc. I would like to able to "protect" the loading of ...
3
votes
2answers
72 views

Making NDSolve choosing by itself a spatial meshing leading to correct integrated results

In a previous post, I was asking how to force a fine spatial meshing in NDSolve using the FiniteElement method. The solution was ...
0
votes
0answers
14 views

exporting graphics has missing features in pdf format in 11.0.1

I am creating graphics with the following code ...
0
votes
1answer
39 views

DSolve Difficulty to Make it work [closed]

I have the following equation: $$\frac { 1 } { 2 } m \dot { x } ^ { 2 } + \frac { 1 } { 2 } k x ^ { 2 } = \frac { 1 } { 2 } k g _ { 0 } ^ { 2 }$$ with initial conditions: $x = 0$ and $d x / d t = ...
1
vote
0answers
30 views

Generic symbols vs Generic functions arguments [closed]

I've got a lot recursion relation that takes multiple hours at a time to run. I'm looking for some subtle reasons why it takes so long, and hoping to be able to reduce the time it takes for the more ...
1
vote
2answers
60 views

Importing Excel File as Dataset

This might be a basic question but I couldn't get it to work. I have a dataset in Excel that I import to mathematica using ...
1
vote
0answers
37 views

CommunityGraphPlot of weighted graph: node too far

I am playing with weighted Graph and CommunityGraphPlot, and I am considering the following example. ...
0
votes
1answer
37 views

\[CircleTimes] (tensor symbol use) in infix conversion (solved)

Reformulated problem. I am using the code: ...
0
votes
0answers
32 views

Simplify doesn't do anything on a matrix, but works fine on its elements separately [closed]

I am performing some operations which arrive at a matrix ...
0
votes
0answers
16 views

Facing difficulty in placing the text In graphics3D

Question 1 I have a cube in which I have to represent the corner of the cube with some text. But I am finding difficulty in placing, I don't want It to be exactly on the corner, I just place in a ...
1
vote
0answers
34 views

Fourier parametric plot running into “Iteration limit of 4096 exceeded.”

I am trying to create a fourier drawing tool like this but am running into an iteration limit on larger images. Being quite new to mathematica, how could I go about fixing this / making the program ...
0
votes
0answers
39 views

Plot Potential, Kinetic, and Total Energy

How do I do this: Make a manipulator that shows the graphs of three quantities on the same plot: potential energy, kinetic energy, and total energy as functions of time. The manipulator will control ...
3
votes
4answers
99 views

Generating $n \times n \times \cdots \times n$ table

Suppose I want to write a function that automatically create a $n \times n \times \cdots \times n$ (all $D$ $n$'s) multiplication table with $D$ as the argument of the function, which is automatically ...
1
vote
2answers
32 views

Replacing a subset of variables in a polynomial [closed]

Let's say I have a polynomial in n variables, e.g. x^3 + xyz + z^2, where n=3 in this case. How can I replace all of the variables in the equation with a certain number? I tried things like ...
1
vote
2answers
123 views

Analytic or numerical integral calculation

I would like to integrate the following, $$f(x,y) = \frac{1}{(a - x)^2 + b (y-x^2)^2},$$ where $a>0$ and $b>0$ between definite bounds to obtain an analytic result ideally. I've tried the ...
2
votes
0answers
23 views

Unexpected symbol::shdw warning during NotebookEvaluate

Consider the following code: ...
0
votes
0answers
18 views

Passing a list of conditions to AND [duplicate]

Say I have a list of some conditions, such as list = {y<x,x<0} And I'd like to plug this into RegionPlot, such as <...
7
votes
5answers
585 views

Ragged Transpose

I have two lists of the same length, the first one a list of integers, and the second one a list of arbitrary-length lists of integers. I would like to make a list of 2-element lists, of all possible ...
0
votes
0answers
64 views

Creating an Executable App

The CreateExecutable and Needs["CCompilerDriver"]` commands can run .exe applications in MMA. I would like to know if it is ...
0
votes
0answers
16 views

Manipulating expressions containing complex exponentials and double integrals

Given that I have Integrate[Integrate[Exp[I w (x-u+v)]f[u, v] , u], v] $\int\left( \int e^{iw(x-u+v)} f[u, v] du\right) dv$ First, I want to first extract ...
5
votes
3answers
81 views

Specify set of base units to use in UnitConvert

I am trying to convert arbitrary units to CGS. I know this can get a bit tricky with ESU, but for this question that does not need to be addressed. What I would like to do is to give a quantity-to-...
4
votes
3answers
73 views

Forcing at least $n$ spatial steps in solving a 1D spatio-temporal PDE problem with NDSolve

I want to solve the telegraph equation with a spatial discretization forced at 200 points. I tried: ...
4
votes
2answers
52 views

How to copy a string to the clipboard from a script?

How to copy a string to the clipboard from a script? I want the wolfram script to copy a string to the clipboard. Unfortunately the following script fails to do this. The same code works perfectly ...
1
vote
2answers
60 views

How can I make an arrow's shaft more visible?

{Graphics[{Arrowheads[.1], Arrow[{{0, 0}, {2, 1}}]}], Graphics[{Arrowheads[.1], Arrow[BezierCurve[{{0, 0}, {1, 1}, {2, 0}}]]}]} say I have the above code. Can I ...
2
votes
0answers
23 views

TimeSeriesInsert for regular series with equal increment breaks regularity

My goal is to combine two time series with common properties and preserve those properties. Say, we have two monthly series: ...
0
votes
1answer
41 views

Make Arrows Smaller

I have the following program that describes a 3D curve in space with an osculating circle and TNB vectors moving with the curve. The arrows indicating the TNB vectors are way too large making it seem ...
1
vote
1answer
44 views

ListCountourPlot does not show any result [on hold]

I was trying to show the heat conduction of Laplace equation problem.But the plot does not show properly ...
1
vote
0answers
29 views

GeoGraphics unable to download data for a given ranges from the Wolfram geo server [closed]

Lately I'm having problems evaluating GeoGraphics functions in Mathematica (version 11.3). For example, when I attempt to evaluate: ...
10
votes
4answers
274 views

Poisson equation with pure Neumann boundary conditions

Dear Mathematica users, I would like to numerically solve a, as the title says, Poisson equation with pure Neumann boundary conditions $-\nabla^2(\psi)=f$ $\nabla(\psi)\cdot \text{n}=g$ Is it ...
0
votes
1answer
70 views

Triple product in spherical coordinates

Given six real numbers $a,b,c,d,e,f$ (say between $0$ and $\pi$) I would like to express the following determinant in a compact and "reasonable" way: $$ \det \begin{bmatrix} \sin a \cos b & \sin ...
4
votes
2answers
346 views

Using LinearSolve instead of Inverse does not give a good enough precision

If I want to calculate $B^{-1}A$, then instead of using Inverse, I should in theory just be able to use LinearSolve[B,A]. Now ...
0
votes
0answers
20 views

FeynCalc example — muon decay — integration issue

I'm just starting out using Mathematica and I'm trying to work through one of the examples given for FeynCalc, specifically the muon decay: https://github.com/FeynCalc/feyncalc/blob/master/FeynCalc/...
0
votes
4answers
64 views

Finding an analytical solution for a quadratic equation

I'm trying to solve an elastoplastic problem analytically (extended Druker-Prager), as an alternative the numerical solution. I need to find xi in the expression ...
1
vote
3answers
74 views

Pass arguments to a function within a function within a function

I want to perform an integration of f[w,t,kx,ky] over t for several different functions f. ...
1
vote
2answers
37 views

Replacement rule for a function and its derivative

I have this equation: EOM1 = Subscript[x1, t, t] + ω1^2*x1 /. Subscript[x1_, m__] :> D[x1[x, t], m] /. x1 -> x1[x, t] The problem with the ...
1
vote
1answer
29 views

Improving efficency in generating Tables with large numbers of values

I'm simulating some transient data for fast Fourier transform -- on the order of 20 million points. Understandably MM takes a while to do this. Are the any techniques in table generation optimisation ...
1
vote
1answer
34 views

Sort a list in a descending order

Say we have a list: {{1/2, -(Sqrt[3]/2)}, {1, 0}, {1/2, Sqrt[3]/2}, {-(1/2), Sqrt[3]/2}, {-1, 0}, {-(1/2), -(Sqrt[3]/2)}} now we want to sort that list by ...
0
votes
0answers
21 views

How to get the coordinates of the x-intercept from a plot?

Assuming that I only have access to the plot and not to the function that was used to generate it, how can I get the coordinates of the x-intercept of this plot?
2
votes
1answer
80 views

Numerically solving the Laplace equation in a 2d cylinder

Consider the following Laplace equation and boundary condition $$\begin{equation}\begin{cases} \Delta \theta(r,\phi)=0 \\ \int d \vec{\ell}\cdot\nabla \theta(r,\phi)=2\pi \end{cases} \end{equation}$$...
1
vote
2answers
41 views

Infix notation for VertexLabels in a Graph (reformulated from a closed topic)

I am reformulating this question as it was incomplete. I want to label vertices in a graph with expressions in infix notation. I copy my code below. First part converts a list of expressions to ...
0
votes
1answer
28 views

Combine list with table

I want to create a three-column table that has a list for one column. But when I do this, using TableForm with TableHeadings, ...
-4
votes
0answers
24 views

Finding and solving polynomial inequalities in scilab [closed]

First I would thank the Mathematica community. i have a system like this: ...

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