All Questions
85,891
questions
0
votes
0
answers
5
views
Remove conditional for ThreeJSymbol
When I evaluate:
Assuming[3 > jj >= 1 && jj [Element] Integers,
ThreeJSymbol[{jj, 0}, {1, 0}, {2, 0}]]
it outputs an expression saying that if
3 > jj >= 1
i get a nonzero answer, ...
- 129
0
votes
0
answers
22
views
Estimation based on previous values using plot
I'm supposed to estimate world energy consumption in 2050. I reasoned that the world's total energy consumption will increase from 2017 to 2050. Is this calculated by looking at the different years, ...
- 101
6
votes
5
answers
64
views
How to "mix" the elements of two lists?
Is there a function in Mathematica that allows me to combine two different lists if the elements in the same position are equal? For example, imagine I have these lists:
...
- 61
2
votes
1
answer
26
views
Force placed Legend into one column
I have a complicated plot (originally a ListLogPlot using many options) with now twelve curves and I would like to force the legend to be displayed in one single column.
Here, I tried to formulate a ...
- 922
7
votes
2
answers
44
views
How to Thread lists elementwise with the If function?
Consider the lists:
list1={a,b,c};
list2={x,y,z};
I want to Thread If elementwise across ...
- 145
1
vote
2
answers
37
views
0
votes
1
answer
23
views
Runge-Kutta of order 4 to solve m first order IVPs using Mathematica [duplicate]
I have the following m first-order IVPs
d(y1)/dx=f1(x,y1,…,ym), y1(x0)=y10,
d(y2)/dx=f2(x,y1,…,ym), y2(x0)=y20,
⋮
...
- 13
8
votes
1
answer
40
views
Change the default name of a new notebook from Untitled-*?
I'd like to change the default name of a new notebook to, say, StringJoin[{RandomWord[],".nb"}].
There is a hint how one might do this in $InstallationDirectory/SystemFiles/FrontEnd/...
- 2,861
0
votes
1
answer
26
views
Is there some method to reture one solution of LyapunovSolve even if the solution is not unique?
I want to find one solution to the Lyapunov equation, and I use LyapunovSolve[a,c]. But when the solution is not unique, Mathematica did not return any value ...
- 113
0
votes
0
answers
13
views
How to set up the default external evaluator for ExternalEvaluate?
I want to use a particular version of Python in ExternalEvaluate. I successfully registered it via RegisterExternalEvaluator. It ...
- 311
5
votes
1
answer
42
views
Can I run terminal commands such as SFTP/SSH through a mathematica notebook?
I'm generating an array using Mathematica which produces a single .dat file. I then use SFTP/SCP to transfer it to the staff Linux cluster.
This isn't a particularly difficult task but is there a way ...
- 71
0
votes
0
answers
14
views
which mxnet files can be deleted?
In an attempt to cleanup my limited space on my C: drive I found these huge file
I guess some might be labeled as version 12.x related but I only use v13.1
Which files can be deleted? The total is ...
- 3,710
4
votes
4
answers
89
views
How to simplify expression through variable substitution
I am trying to simplify a complicated expression through variable substitution and part of the expression looks like:
$2A_1^2+A_1B_2+2B_1^2-B_1A_2+2C_1^2+C_1D_2+2D_1^2-D_1C_2$
I want to substitute $...
2
votes
1
answer
34
views
Floating LogScale histogram
I have a histogram that I represent on a base 10 semi-log scale, and I need to fix the plot range. If I set the lower bound for the logarithmic axis, the histogram bins do not stretch downward fully. ...
- 21
0
votes
0
answers
24
views
How to move the last and first tick to the bottom and top of frame in plot?
I have this grid with three graphs:
I want the top and bottom ticks to align with the top and bottom of the frame. So that there wont be a space between the 650 tick and grid line and the top of the ...
- 161
4
votes
1
answer
58
views
0
votes
0
answers
21
views
Avoid rounding in svg exported colors
The code
ExportString[Graphics@{Red,Rectangle[]},"SVG"]
yields
...
- 3,099
2
votes
1
answer
173
views
Why does "Solve" not work for integral?
I have defined the following function:
f1[c_] := -Integrate[E^(-t), {t, 0, y}] -
Integrate[E^((-c)*t), {t, y, -Log[1/2]}]
When I solve this for c=1, I get f1(1)...
- 23
1
vote
1
answer
54
views
NestWhile question, ensuring a function is repeatedly applied to a newly set input-value
Problem: I need to ensure that a function which is repeatedly called in NestWhile correctly uses a newly computed input on its next call. I will give the context while omitting parts of the code (...
- 1,274
0
votes
0
answers
27
views
Create a notebook with no menu bar
I would like to create a notebook with a specific name and no menu bar. The following code:
...
- 5,340
0
votes
0
answers
60
views
Integration using CUDA kernels
I have never work with CUDA in Mathematica. My task connected with the calculation of a big amount of the same integrals. I have only 8 cores processor but my PC also has video processor with large ...
- 101
0
votes
0
answers
29
views
An Error in `MATLink`
I downloaded MATLink to the directory generated by the command: (Matlab 2022b and Mathematica 13.1 on windows 10)
...
- 507
9
votes
1
answer
200
views
How to convert a Markdown file into a Mathematica notebook
How to convert a Markdown file (or text) into a Mathematica notebook?
For example, easy conversion of comprehensive MSE posts is desirable.
Possible approaches ordered according to their convenience:
...
- 35.8k
1
vote
2
answers
61
views
Insufficient memory in Nonlinear Model Fit with ParametricNDSolve
I try to fit parameters to ODE solver with chemical kinetic eqations:
...
- 105
0
votes
0
answers
27
views
3
votes
2
answers
83
views
MeshFunctions in ParametricPlot with BSplineFunction for parameter extraction
I would like to use MeshFunctions in ParametricPlot in combination with BSplineFunction to ...
- 33
0
votes
3
answers
75
views
Interpolation of a function from numerical data and getting plots
I need to plot between two functions $f(h)$ and $g(h)$. I have the numerical data of $f$ w.r.t. $h$. So I just tried to get the expression of the function using the codes f[x_]=Fit[data,{1,x,x^2},x] ...
1
vote
1
answer
39
views
1
vote
1
answer
14
views
Create and copy whole cell before NotebookApply
I have created a button with a NotebookApply associated, something similar to the following
...
- 540
0
votes
1
answer
34
views
Getting 3 points although the code describes 1 point in the plane
I'm trying to plot the closest point in the plane to the point P (the one that can be dragged) but in the graph appears 3 points.
in the graph I'm plotting a plane and a point P, I want to add another ...
- 179
0
votes
0
answers
35
views
How to make a plot that includes two different graphs AND arranges it in a grid? [closed]
I want to create this:
I have these functions:
...
- 161
-1
votes
0
answers
36
views
How can I loop a findRoot untill some condition has been met?
I need to do something quite simple.
I have a findRoot, that in the end of the findRoot updates a number that changes the findRoots results. I need to repeat the findRoot until some condition is met.
...
- 161
1
vote
1
answer
94
views
Find prime numbers p and q
The question is:
Find primenumbers p and q if n=pq=39247771 and φ(n) = 39233944.
Does anyone have an idea of how to approach this problem in mathematica?
Thanks in advance
- 63
1
vote
1
answer
69
views
Matrix-Calculus: Expression Visualization
There is a vector matrix expression:
$q=x \cdot x^T$
Where $x$ is $3 \times 1$ vector.
I want to visualize the structure of this equation, but so far the only thing that came to my mind is to use the <...
- 1,893
0
votes
0
answers
34
views
Plotting functions of two variables [closed]
I am new to Mathematica and I have this function:
$$f(x,y)=x^2+2 x y+2 y^2,-4\leq x\leq 4,-6\leq y\leq 4$$
Which command should I use to plot a function of two variables instead of ...
- 1
0
votes
0
answers
26
views
NDSolve_WhenEvent_Results analysis
I have used NDSolve to solve a motion equation, which is about particle moving in a electric field above a platform. And I used WhenEvent to consider the condition ...
- 55
3
votes
1
answer
46
views
Stochastic process: Understanding Ornstein Uhlenbeck Process
Recently, I have been trying to simulate a random/stochastic variable that follows Gaussian distribution and also has an exponential correlation function $\left\langle X(t)X(s)\right\rangle= e^{-\frac{...
- 549
2
votes
1
answer
29
views
How can I place DistributionChart at desired x values?
Consider a simple DistributionChart such as the following:
...
- 153
0
votes
1
answer
62
views
generate right triangles of different measures with an unknown data
hello (edited and clarified) Could you help me improve this code to generate at least 10 "slightly larger" right triangles, but with small random data between 1 and 20 on two of the sides, ...
- 191
0
votes
0
answers
27
views
Slow SmoothKernelDistribution of WeightedData
Consider some data in the form
data = {{x,y,weight(x,y)},...};
I make
wd = WeightedData[data[[All,{1,2}]],data[[All,3]]];
I ...
- 4,116
11
votes
1
answer
540
views
How do I unlock a Mathematica Notebook?
I downloaded Wolfram's Intro to Mathematica in Notebook format. I like to experiment as I study but you can't edit the notebooks. They are locked for some reason. So I still have to open a work ...
- 349
1
vote
0
answers
28
views
Unable to open Arduino device
I have a problem opening an Arduino device: I tried everything, but it keeps giving me this error message. Does anybody know how to fix it?
I use Wolfram Mathematica 13.0 on Windows 10. I downloaded ...
- 11
0
votes
0
answers
41
views
How to abort an evaluation in the terminal
I am running Mathematica 13.1 via the terminal over SSH on my university's computing cluster, inputting the commands interactively in the terminal, not via a frontend. However, sometimes (perhaps due ...
- 203
0
votes
0
answers
24
views
Set the MPC tracker arguments
I have an affine system $\dot x(t)=X(x(t))+u(t) Y(x(t))$ with one input $u$ and two outputs (corresponding to the state $x=(x_1,x_2)$ of the system) and I would like to start from ...
- 442
1
vote
2
answers
67
views
A bug in InputField of type Expression?
I have a problem with a simple InputField of type Expression:
...
- 60.3k
7
votes
1
answer
135
views
Using CityData[] vs. Entity for population
I am using v12.2.0-Win7-x64.
CityData[Entity[
"City", {"Shanghai", "Shanghai", "China"}], "Population"]
...
- 19k
2
votes
1
answer
85
views
How to assign a value to something inside a module globally?
Let's say I created a function that calculates something inside a module. How do I assign that result to a global value?
Let's say I have this:
...
- 161
5
votes
3
answers
271
views
Replacement question
I have this equation
F2 + F4 - V1 + V3==0
I want it to be converted automatically via a replacement rule to
...
- 1,213
1
vote
0
answers
68
views
Solid mechanics - traction boundary condition in the reference configuration
Both SolidBoundaryLoadValue or NeumannValue can be used to specify the traction boundary condition, because ...
- 135
1
vote
1
answer
62
views
How to solve the error "Delay partial differential equations are not currently supported by NDSolve"?
Here I want to solve the partial differential equations
...
- 101