All Questions

0
votes
2answers
51 views

Correct interpretation of an ODE solution

I am not very good with Mathematica but I am trying to solve the following initial value problem $y''(t)=\lambda_1 y'(t)e^{y(t)}+ \lambda_2 y'(t)e^{-y(t)},$ $ y(0)=0$ I have tried first the ...
1
vote
0answers
13 views

Label quartile / quantile data

I searched for a WL implementation of the Python Pandas qcut function but could not find one. Anyone aware of an implementation? For the moment I just need quartiles and the assignment of values in ...
0
votes
0answers
17 views

How to solve this 1st-order linear ODE system

Consider an ODE eigensystem $$ ty\,a(y)+[(q+\frac{y+1}{2})+(y\partial_y+\frac{1}{2})]b(y)=\lambda a(y)\\ ty\,b(y)+[(q+\frac{y+1}{2})-(y\partial_y+\frac{1}{2})]a(y)=\lambda b(y) $$ where $q,t$ are (...
0
votes
1answer
25 views

double Integral in complex number field

The following expression is an expansion of Hypergeometric2F1 function from the above expression with the help of 9.113(in 'Table Of Integrals, Series And Products'). but I got different results.WHY? ...
2
votes
2answers
83 views

Creating a function that is a variant of Length

I want to create a new function nLength that applies Lengthin each element from a list automatically. For example: I have a ...
1
vote
0answers
13 views

How to get the events occurred on a list of dates?

I have a list of 100 unix timestamps and I am trying to get all the events occurred on that time. The following code get an abort signal when a has 100 timestamps. Another problem is that when I run ...
2
votes
1answer
33 views

Draw functions on Plot3D

I have a 2D function $f(x,z)$ which I render with Plot3D. In the plot, on top of the surface, I want to plot 1D functions at $f(0, z)$, $f(100, z)$ and $f(200, z)$. ...
3
votes
1answer
58 views

How to implement split-complex numbers?

For those who do not know, the split-complex numbers are an analogue to the complex numbers where J is defined such that $J^2=1$ but $J\ne\pm1$, so they are all of the form $a+bJ$. By using ...
0
votes
0answers
57 views

About creating my own fuction `ArrayQ`

I want to create my own function ArrayQ using Mathematica's functions as little as possible. I already have the "new" function that I called ...
11
votes
1answer
193 views

MousePosition in AttachedCell?

I can't figure out why the following stops working when "WindowAbsolute" is replaced with "Graphics"? ...
0
votes
0answers
25 views

Defining a derivative as a function does not work

I have a fairly complicated function VIcase1L[b_,\[Epsilon]_, d_] := ....... All I wanted to to was to derive it this function with respect to b and define it. ...
3
votes
0answers
21 views

Wolfram Mathematica 11.3 crashing on either startup or after typing in a notebook

I have been having an issue with my Mathematica 11.3 installation. Often after running a notebook for a long time, my Mathematica will crash suddenly for strange reasons like just typing in the ...
0
votes
0answers
30 views

Importing large csv files

I'm trying to import a large csv file (around 1.5GB) so I can multiply one of the columns, and plot it against another. There are seven columns in the file when I try and open it in excel, and I need ...
1
vote
0answers
29 views

Calling a notebook from a different notebook

Basically I have a notebook (let's call it nb1) that when evaluated yields one number when I specify some parameter $\alpha$ (in nb1). I want to call nb1 in a different notebook (nb2) using for ...
0
votes
0answers
22 views

Change the attributes of the function `Format`

I think that the function Format has intrinsic an orderless attribute. So I've tried to create the following function: ...
0
votes
0answers
13 views

How can I get an array of very large primes when I don't have a lot of memory?

I would like to perform computations on an array of primes within the range $[2,10^{15}]$. For the moment, I am selecting such an array using the command: ...
1
vote
0answers
20 views

Issues computing expectation

I am interested in computing a conditional expectation, but not sure what is the best way to do it. All the methods I have used seem to have issues. Let $Y=X_1+X_2$ where $X_1$ and $X_2$ are ...
0
votes
0answers
44 views

How to graph acceleration from an equation given a sample period?

I am unfamiliar with Mathematica and the necessary syntax to approach visualize acceleration over time. I would appreciate some assistance or reference to a starting point on how to go about solving ...
0
votes
0answers
25 views

How to verify if all elements of a list are equal [duplicate]

I have a result in a list form: {1,2,3,4,5,6} How to verify if the elements are equal? If I use Equal doesn't works with a list....
18
votes
3answers
519 views

Usage Examples for DynamicWrapper

I am looking for practical uses of the function DynamicWrapper . I read documentation and know whatever it says. I would appreciate a clear example of a useful ...
2
votes
2answers
125 views

How to apply `Length` in all elements

I want to apply Length in each element from a list. For example: My list is: {1,{2,3},{4,5,6}} How to apply ...
0
votes
0answers
8 views

ParallelTable fails to finish evaluating after completing computation

I am executing a ParallelTable but the code fails to finish. This is the setup. f is a function. ...
1
vote
1answer
18 views

Converting Graph3D to Graphics3D

How you do convert a Graph3D (or GraphPlot3D) into Graphics3D? Graphics3D@ButterflyGraph[3] ...
0
votes
1answer
32 views

How to pass a list to APIFunction?

My problem is I have a list of 170 values. To use API function, I had to represent these values by 170 parameters (not the most elegant thing). My question is, can I pass a list to APIFunction, or ...
5
votes
1answer
59 views

GeoListPlot exact addresses

In GeoListPlot the locations are supposed to be GeoPosition or Entity objects representing ...
2
votes
0answers
14 views

Export CAD .STEP files format with Mathematica?

This question is related to following question: questions/130883 which has not been answered yet, because a workaround has been found using an import feature from Autocad. Basically, I want to ...
0
votes
1answer
68 views

Interpreting Mathematica code on black holes

I am trying to understand the code written down on page 7 of this document (code is in Mathematica) I understand pretty much all of the code on the previous page needed to setup the page 7 code (...
3
votes
2answers
89 views

Operation acting on arbitrary number of matrices, element-wise

I have a certain number of $N \times M$ matrices: $$ M_1 = \begin{pmatrix} a_{11} & a_{12} & ... & a_{1M} \\ a_{21} & & & \\ \vdots & & \ddots & \\ a_{N1} & &...
0
votes
1answer
18 views

How do I size a Manipulate input field when using Control?

I'm building a Manipulate object and I need to reduce the width of the input fields for improved usability. I've tried everything I can, and I don't seem to be able to get it. Everything points to ...
0
votes
0answers
43 views

What is the “phone” symbol that appears with the keyboard shortcut “ctrl-g” in mathematica 11.1?

Using ubuntu, and mathematica 11.1, the keyboard shortcut ctrl+g creates a small emoji of an old landline phone (see image). It does not appear in mathematica 10. If I copy it from 11.1 end up with ...
0
votes
0answers
19 views

How to make ListPlot work for Table output on this for {{matrixElement}}?

I am using Table to get values for some expressions (see code below): ...
4
votes
5answers
404 views

Sum of list numbers smaller than one goal

I have five values ​​that I would like to add them so that they can be equal to or less than 3000. ...
4
votes
4answers
63 views

Get complete graph from set of vertices?

There is a function in Mathematica called CompleteGraph which takes a number and makes a complete graph with that number of vertices: ...
0
votes
0answers
43 views

How to resolve the fail when applying a user-defined solver?

The user-defined function pdetoode and pdetoae, developed by @xzczd, is very useful to deal with a PDE system when there is ...
1
vote
2answers
57 views

Simplifying polynomials [on hold]

I have noticed a strange behaviour in Mathematica regarding simplifying polynomial expressions. Take the following polynomials pol1=3-8s+4s^2 pol2=(2s-1)(2s-3) ...
0
votes
2answers
36 views

How can you define a function with variables and put it equal to a function that is already defined? [on hold]

Lets say you have a function: f = x^2 + y^2 Now I want to define a new function of x and ...
1
vote
0answers
33 views

Antiparticles in Feynrules Lagrangian

I am trying to implement a simple extension of the SM to Feynrules, generating the Lagrangian in a Mathematica notebook file. I am wondering about the following: Is there a way to explicitly use the ...
2
votes
0answers
42 views

Flight information data

I would like to write a program that automatically checks whether a given flight number is correct and the corresponding departure and arrival times. Is there any function from the Wolfram Language ...
1
vote
0answers
28 views

How to draw 2D plots into a 3D graph in mathematica? [duplicate]

I want to stack 2D plots into a 3D graph, for example I have a function F=(3x+y(2+5y))/23 of two variables x and y, and want to plot like this need help in mathematica program plz
28
votes
5answers
6k views

Plotting several functions

I'd like to plot a function of one real and one integer variable, but I don't want them all shown in the same 2-D plot - I'd like to see them as separate curves so I can see both "axes", more like how ...
7
votes
1answer
1k views

Fitting a numerical integral via NonLinearModelFit to magnetic data

I'm new to Mathematica and I'm currently trying to fit $$m_T (H,T) = N_T \int\limits_0^{\infty} \frac{x k_\text{B} T}{\mu_0 H} \mathcal{L}(x) \text{pdf}(D_\text{mag}) \text{d}D_\text{mag}$$ with $x=\...
7
votes
0answers
53 views

Matrix-free Arnoldi method for eigensystems

I am solving a generalized eigenvalue problem $$\mathbf S\,\mathbf x = \lambda\,\mathbf M\,\mathbf x$$ w/ $\mathbf S := \mathbf B\,\mathbf A^{-1}\,\mathbf B^{T}$, and $\mathbf A$ is a sparse ...
7
votes
1answer
588 views

How do I use low level FEM?

How do I simulate the following partial differential equation using Low level FEM in Mathematica? D[u[x,y], x] - D[u[x,y], y] = x Sin[x y] - y Sin[x y] The ...
2
votes
1answer
89 views

How to solve this 2nd-order ODE with quadratic coefficients?

Consider an ODE eigensystem $$ \begin{bmatrix} 0 & d_1-\mathrm id_2 \\ d_1+\mathrm id_2 & 0 \end{bmatrix} \begin{bmatrix} a(y) \\ b(y) \end{bmatrix} = \lambda \begin{bmatrix} a(y) \\ b(...
0
votes
0answers
48 views

How to make a phase diagram (vector plot) using results from NDSolve?

I solved the next differential equations using NDSolve, so I got two solutions ϕ[t] and H[t]....
1
vote
1answer
26 views

Unable to add window title in SystemDialogInput

There appears to be an option called WindowTitle for the SystemDialogInput, but it does not seem to do anything for me: ...
0
votes
1answer
39 views

Conditional expectation using derived distribution [on hold]

While this question can be solved using some (hand) analysis and standard calculus, I would have thought that the following code would have worked: ...

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