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3
votes
2answers
74 views

Extract outputs from a WHILE loop in a table format

How can I convert my multiple outputs of a while loop in a table form and save it for later use. Here is a sample code: ...
5
votes
1answer
54 views

Combining 3D graphics with different lighting conditions

I would like to create a 3D graphic of the bust of Beethoven with specified lighting position, as well as a small (colored) set of axes. I would like the axes to not be affected by the position of ...
2
votes
1answer
35 views

Do not skip empty table entries while importing data from HTML string?

Consider importing the following table from an HTML string: ...
0
votes
1answer
82 views

FindRoot: Power: Infinite expression 1/0. encountered

I am trying to solve the problem below with FindRoot. At first it works well, but when I change the constants in my equation the solver returns with the message: ...
0
votes
1answer
48 views

WolframScript not simplifying output

I'm trying to multiply a matrix and a vector (imported from a csv) in Wolframscript to speed up a process normally done with Mathematica notebooks. This is my first time using Wolframscript, however, ...
0
votes
0answers
33 views

Why does NumberForm disturb the output of Rationalize? [duplicate]

I am currently using Rationalize after NumberForm in order to check if the some values of my function are in the ...
2
votes
1answer
91 views

Plot feasible region of a high-dimensional LP only along some dimensions

I have a question on the possibility of using Mathematica to plot a convex closed region satisfying a linear system of equalities and inequalities. Let me first present the linear system. Let $x\...
0
votes
1answer
63 views

NDSolve::ndsv: Cannot find starting value for the variable w

I cannot find theNDSolve::ndsv error in this code ...
2
votes
0answers
52 views

Notebook (.nb) → Jupyter (.ipynb) conversion without Mathematica?

Is there a way to convert Mathematica Notebook files (.nb) to Jupyter files (.ipynb) without using Mathematica?Is there a free online utility or other piece of software that can do this?
1
vote
2answers
43 views

Restrictions as string to expression in region plots

I'm trying to build a function that generate a string of restrictons to pass on to a region plot with ToExpression, but I think it fails to pass the plot variables. ...
2
votes
0answers
40 views

How can you set the fit tolerance in `NonlinearModelFit`?

In NonlinearModelFit how can you set the tolerances of where the fitting terminates. I know you can set MaxIterations but how ...
0
votes
1answer
66 views

Matrix of functions

I want to create a matrix of functions. As explained in this question, I can create a matrix of variables: ...
0
votes
2answers
44 views

problem with constant variables

Variable x is supposed to be constant, but the program calculates for each variable x, 100 numbers of x. I want all my x variables to have the same definition, but the program constantly changes each ...
-1
votes
1answer
57 views

How can I calculate sum of multi-index

Does anyone have idea to move the i? Here is Mathematica language: f[n] = Sum[2^(i - 2 - 2^(i - 1)), {i, 2, n}] The output ...
0
votes
0answers
60 views

1D transport equation with Neumann conditions

I'm trying to solve 2nd order differetntial equation of heat transfer-type in a finite system x<0,L>, in particular: ...
2
votes
0answers
66 views

Double shell wall contact with AceGen

I have a shell with double walls and some space between (Picture 1). The 2 walls are connected with three edges. If I apply force to outer wall and if the force is big enough, outer shell wall will ...
3
votes
1answer
50 views

find a maximum parameter for a range of target eigenvalues as a function of matrix dimension

I have a symbolic tridiagonal matrix of this form ...
2
votes
2answers
88 views

Map vs. Table for index-specific operations on 2D arrays–Part II

This is an extension of my recent question, Map vs. Table for index-specific operations on 2D arrays For that question I gave a minimal working example, since I was more interested in learning ...
0
votes
0answers
30 views

Mathematica Scalar Field on 3D Space

Fellow Mathematicai, is there any way to create a visual plot of a Scalar Field on 3D space in Mathematica? With Gratitude, - SDH
1
vote
1answer
56 views

TrueQ returning False on true, non-numerical statement

I'm trying to test the following logical statement: state = {{1,1,1}}; Or[state != 0, state != Null] but it's returning False ...
1
vote
1answer
41 views

Combine a List of Plots: Using MapThread with Show [on hold]

I have a list of graphics p1 = Plot[x Sin[x] - 1, {x, -2.5, 2.5}] p2 = Plot[Evaluate[D[x Sin[x] - 1, x]], {x, -2.5, 2.5},PlotStyle -> Red] ListNew = {p1, p2}; ...
0
votes
2answers
55 views

Get the derivative function plot from a NDSolve solution

I been trying to plot the derivative function of j[t], being j'[t]. Here a look to the code. I would appreciate your help. Thank you ...
0
votes
0answers
30 views

how to change axis range [closed]

I wanted to plot a function with different form of axis range
6
votes
1answer
57 views

why this call to StreamPlot returns unevaluated? (no error message, no beep)

I am really baffled by this. Call to StreamPlot does not return empty plot, nor an error message, nor a beep. It just return unevaluated. I do not think I've seen ...
0
votes
0answers
44 views

How to solve the following iterative volterra integral equation? [closed]

choose a_n = 0.5947894739; x_(n+1)=(1-a_n)x_n + a_n{x_n + NIntegrates(1-t)[x_n'' (s) - 3/2 x_n^2 (s)], {s, 0, t}, {t, 0, 1, 1/10}]}
3
votes
2answers
83 views

visible indication that a cell is not evaluatable

Occasionally I make cells not evaluatable. Is there any way to have some sort of visible indication (automatic) that reminds me if a cell is not evaluatable. One example of why I do this is that we ...
0
votes
1answer
71 views

Nonlinear fitting does not perform appropriately

I have a list as below one: mustbefitted={{0., 1.}, {4.4, 0.982211}, {8.9, 0.961575}, {13.3, 0.942571}, {17.8, 0.923857}, {22.2, 0.906203}, {25.1, 0.046994}}; I ...
1
vote
1answer
24 views
3
votes
2answers
257 views

Plotting octahedron inside the sphere and sphere inside the cube

How to plot an octahedron inside a sphere and the same sphere inside a cube in 3d?
0
votes
1answer
59 views

Fitting data with NIntegration related function

I am trying to fit experimental data with data file given below function, but I am not able to find the best fit. Constant value is A=6.26 and ...
1
vote
2answers
47 views

extracting pairs in which y-component has a relative maximum value

I have a list of several pairs. You can find it here or create it manually. Applying ListPlot on the intended list results in the below plot: How do I extract ...
-1
votes
0answers
47 views

Removing destroyed elements AceFEM?

does anyone knows is there in AceFem a way to remove elements from the model which are being destroyed during analysis? I have an analysis in which damage paramter based on energy is caluclated. I ...
1
vote
2answers
95 views

How can I combine two contour plots into one and give it a bar legend?

I have these contour plots: ...
0
votes
1answer
22 views

Surface to be printed appears with virtual Thickness?

...
3
votes
2answers
894 views

Two matrices that are not similar have (almost) same eigenvalues [closed]

I have two matrices $$ A=\begin{pmatrix} a & 0 & 0 \\ 0 & b & 0 \\ 0 & 0 & c \end{pmatrix} \quad \text{ and } \quad B=\begin{pmatrix} d & e & f \\ d & e &...
0
votes
0answers
25 views

Triggering update of an InputField that has {Temporary,updatefunction} [closed]

I have a DynamicModule that contains a number of InputFields and a Button to cause ...
4
votes
0answers
53 views

Double summation giving unexpected result

The expression (in a notebook with Wolfram Mathematica 12.0.0) Sum[s[i, j] - s[j, i], {j, b}, {i, b}] Produces the result 1/2 b EulerPhi[b] Can anyone ...
0
votes
0answers
35 views

How to approach convolving two functions [on hold]

For some background, I'm interested in looking at the effect of window functions on the lineshapes of power spectrum densities in the frequency domain. For example if I convolve a Hanning window with ...
1
vote
0answers
139 views

Mollweide Projection of a Sphere [duplicate]

I want to recreate the following picture for a project. However, I am not sure how to do this with Mathematica. Is there an easy way to obtain just the "background" picture of the sphere without the ...
0
votes
0answers
30 views

Why Through[] does not work in FindMinimum? [closed]

Could anybody please help with the following problem? I want to stop a minimization of function, which does not have a minimum, without error message. I am trying to use the ...
0
votes
0answers
34 views

How to obtain the gradient of a function wrt a vector?

I'm new to mathematica and I wanted to obtain the gradient of the following function: where b_k(s) is the cubic B-spline basis function associated with control point k. I tried this code: ...
10
votes
7answers
945 views

How to take the beginning and end parts of a list with simpler syntax?

So basically you have a table of some values, let's call it a: a=Table[n,{n,10}]; (*{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}*) And you ...
-1
votes
0answers
51 views

Iverson bracket in mathematica

In mathematics, Iverson's convention [P(k)] is a boolean value of condition $P(k)$, for instance, $[P(k)]=0$ if $P(k)$ is false and vise-versa. Iverson's convention is very useful since it opens for ...
3
votes
1answer
116 views

function evaluation - I don't get it

this function returns Pi/4 for a[1,4] In[...]:= a[r_, n_] := Module[{an = Pi/n, h = r Cos[an], w = 2 r Sin[an]}, an]; a[1, 4] Out[...]= Pi/4 so the kernel ...
2
votes
1answer
48 views

How to include Thickness for surface in Contour Plot? [duplicate]

ContourPlot3D[ f(x,y,z) ==0, {x,xmin,xmax},{y,ymin,ymax},{z,zmin,zmax},ContourStyle-> Thickness[2.0]] Like in this case Thickness does not appear to Show: <...
0
votes
0answers
5 views

How to reverse ArrayPlot Axis labeling [duplicate]

I have an odd incompatibility between Frame labeling and DataRange and DataReversed in ...
0
votes
1answer
86 views

How can I get the Eigen system of a certain matrix? [on hold]

How can I get Eigen system of c, where c = a - iota * b? Please help me to find the Eigen system in a nice form. ...
2
votes
0answers
25 views

How to run a wolfram-server safely on a VPS as a backend of a webpage?

If one runs SocketListen on a Virtual Private Server (VPS), in principle one can set up a webpage with the Wolfram Language as a back-end. For instance, with ...
1
vote
1answer
59 views

Inversion of a hypergeometric function

I have been trying to invert the hypergeometric function $$\rho(r)=\frac{2b}{1-q}\sqrt{1-\left(\frac br\right)^{1-q}}\,_2F_1\left(\frac{1}{2},1-\frac{1}{q-1};\frac{3}{2};1-\left(\frac br\right)^{1-q}\...
5
votes
3answers
427 views

Is $2x$ documented?

According to the official documentation of Times[], multiplication of $x$ and $y$ is represented as one of x*y x×y ...

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