# All Questions

57,893 questions
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 ...
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### 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 ...
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 (...
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### Perform an explicit summation, if possible, over a restricted range of two indices both varying from 0 to infinity

I would like to sum the term ...
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### 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? ...
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 ...
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 ...
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 $f(200, z)$. ...
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 ...
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 ...
193 views

### MousePosition in AttachedCell?

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

### Sum a certain hypergeometric-function-based expression pertaining to an integration problem

I would like to sum over the index $h$ from 3 to $\infty$, the expression ...
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 ...
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### 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 ...
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 ...
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: ...
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### 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: ...
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 ...
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 ...
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....
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 ...
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 ...
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. ...
18 views

### Converting Graph3D to Graphics3D

How you do convert a Graph3D (or GraphPlot3D) into Graphics3D? Graphics3D@ButterflyGraph[3] ...
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 ...
59 views

In GeoListPlot the locations are supposed to be GeoPosition or Entity objects representing ...
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 ...
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 (...
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Writing: ...
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### 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]....