# All Questions

27 views

### Issue plotting PDE solution with manipulate

I am trying to plot the solution to the following PDE with the help of mathematica, however, when trying to employ manipulate to animate the behavior, I find that if I try this: ...
110 views

### How to extract a Graph[] from an image?

This graph (as a picture) is given below: I am wondering rather than setting up this network graph using Mathematica syntax such as PathGraph,...
134 views

### Insufficient size of Graphics

The following code returns a framed text box that is longer than the standard width of Graphics'. ...
52 views

### Finding a seven-digit number with all of its prime factors less than 20? [on hold]

How can I find a seven-digit number with all of its prime factors less than 20? I have no clue how to do this.
117 views

### Strange behaviour of NotElement in Reduce

I have observed curious behaviour on domains supplied to NotElement and Reduce and domain of an argument in calculation inside ...
46 views

### Plotting certain time points in a parametric equation? [on hold]

I'm using Mathematica 5.0 and I have the following problem. I have the following parametric equation that I plotted successfully. ...
56 views

### Unexpected behavior of Set [on hold]

Set doesn't work in some conditions. ...
54 views

### Implicit differentiation dx/dt?

I am trying to find $\frac{\partial t}{ \partial y}$ as a function of $x$, $y$ and $\frac{\partial t}{\partial x}$ if both $x$ and $y$ depend on $t$ for the function ...
70 views

### What's the easiest way to remove overall factors from polynomials?

I have code that outputs polynomials (in #1) such as the ones below (note that the trailing Function character ...
14 views

### Export a .NOFF file without color information

I have the following piece of code: ...
87 views

### Color a single contour from a ListContourPlot3D using values from a list

I want to map an electrostatic potential onto a density map. How can I color a single contour from a ListContourPlot3D using the values from another list? Make ...
277 views

### How to numerically solve a 1-d time-independent Schrodinger equation?

The point is to solve the eigensystem of the given Hamiltonian. I tried ParametricNDSolve combined with FindRoot to search for ...
56 views

### Split Boundary Value Problems win Algebraic Equations

Is it possible at all to solve with NDSolve (or other built in function) a split boundary value problem with algebraic equations? Please look at the following example: ...
160 views

### How can I solve a 3D heat transfer partial differential equation? [closed]

It's a problem about heat transfer. Here is the equation : Is it solvable using this software? Edit Sorry, I'm new to Mathematica. I have the following code for this problem ...
143 views

### Chromatic number for “great circle” graph

I would like to calculate the chromatic number for a great circle graph. I tried this example in this link. I first tried to calculate the chromatic number for ...
42 views

### Need Help with solve function [on hold]

I'm trying to re-write this function x = e^(-(r+(1/2)*sigma^2)*t-(g)(sigma)*sqrt(t)), as an expression of "g" instead of "x" ...
27 views

### what's my air speed if i know these details [on hold]

What is the minimum air speed required of an F4 phantom aircraft to accelerate at 10g while pulling the nose up from a 20 degree pitch down attitude?
92 views

### Differential equation in two variables

I have a system of second order differential equations, with two independent variables, which represents a trajectory. I tried solving this system using NDSolve and ...
67 views

### Except[] with levelspec

I am trying to determine all the variables used in list. For This I use: DeleteDuplicates[Cases[l1,_Symbol,-1]] This is great except that ...
47 views

### 3D orbits of moons around their respective planets

I have seen a lot of solar system models (both animated and not), but I am trying to replicate the same thing with moons. Either just one planet and its lunar system or the our whole solar system with ...
231 views

### why MatchQ is fast and Replace slow?

Consider a large expression, say a polynomial with 25 terms expr=Product[Unique["a"],{i,1,25}]; to which you apply the following replacement rule: ...
38 views

### Possible Bug with DateObject

So my questions is going to be hard to duplicate because I am not sure when or why it happens. I've read here several bugs with DateObject, but none of them ...
34 views

### How to run code in two notebooks simultaneously [duplicate]

I have the problem that I cannot run code in a second notebook when another notebook is being executed (here only a single core is used). The CPU of my computer has 4 cores (Win 10, Mathematica ...
2k views

### What would you ask Mathematica to do on a big system?

Our hardware supplier has given us the opportunity to test Mathematica on a big Windows system. The specs will be 1 to 4 TB of working memory and 12 sockets with 18 cores each. I got 1 full week of ...
51 views

### Product of two Meijer's Function

I want to evaluate an integral $I_1$ defined in $Eq.(1)$ as \begin{align} I_1=\int_{0}^{\infty}\frac{x\exp(-\beta x)K_1(\alpha x)}{1+x}dx\tag{1} \end{align} Where $\alpha\geq0$, $\beta\geq0$, and ...
60 views

### Computing quadrature points on triangle

According to http://math2.uncc.edu/~shaodeng/TEACHING/math5172/Lectures/Lect_15.PDF page 7, it is possible to compute coordinate of quadrature points by using the script ...
252 views

### Is there a method to enumerate the keys/values of SystemUtilitiesHashTable

Lacking from the simple API of SystemUtilities`HashTable is a method to enumerate the keys/values. ...
32 views

### Shortcuts for Indentation in Text Cells?

Marking a cell's bracket and then using Alt-7 I can make it a Text cell using the formatting set forth in Default.nb or in a modification of it stored with the notebook itself (so called "private ...
62 views

### RandomPoint fails with a large enough number of points

Bug introduced in 10.2.0 and fixed in 10.3.1. RandomPoint is new in 10.2.0. I have defined a simple ellipsoidal parametric region: ...
36 views

### Limit involving DiracDelta gives zero [on hold]

Why is the following limit zero? In[147]:= Limit[DiracDelta[ϵ], ϵ -> 0] Out[147]= 0 It does not matter if the limit is taken from either sides (+/-), since ...
29 views

### Hidden assumption in Mathematica integration [duplicate]

If I do Integrate[Exp[I*omega*t],t], it gives me $\frac{1}{\omega} e^{i \omega t}$, as expected in most of the cases, except when $\omega$ is 0. Mathematica seems ...
104 views

### FilledCurve inside GraphicsComplex doesn't interpret the integers as points

Bug introduced in V9.0 or earlier and persisting through V10.3.1. Here's an example: ...
155 views

### Grid cuts my images

Bug introduced in V9.0 or earlier and persisting through V10.3.1. pic2 = ImageResize[ ImageCrop@Rasterize@Graphics@Disk[], {Automatic, 40}] ...
651 views

### FEM: user material subroutines (UMAT in ABAQUS), mechanics

Just a quick question (mainly for those who are also familiar with ABAQUS or other comparable FEM programs and non-linear modelling of mechanical behavior, e.g., plasticity). Is there any module in ...
46 views

### Force mathematica to consider variables as real [on hold]

I want to implement an optimization of the form: NMinimize[{function,{constraints:A1^2+A2^2+A3^2+A4^2 ==1}},{A1, A2, A3, A4}] where I want to tell mathematica ...
39 views

### Bilinear interpolation [on hold]

I have a matrix with n rows and m columns. I would build a two-variables function which interpolates these points (it's a bilinear interpolation problem). How can I found a two variables function ...
49 views

### How can I convert a 3D contour plot into a region for use as a custom slice in ListSliceDensityPlot3D?

The documentation for ListSliceDensityPlot3D says ListSliceDensityPlot3D[{{x1,y1,z1,f1},{x2,y2,z2,f2},…},surf] generates a ...
70 views

### Calculating products of given length of two matrices

I have the following problem to solve. Let us have two given square matrices $A$ and $B$ of the same size and a positive integer $n$. I would like to produce all products of length at most $n$ of ...
29 views

### How can I get a list of the “coefficients” of Quaternion[1, 2, 3, 4]? [duplicate]

I want to input: Quaternion[1, 2, 3, 4] to get a list: {1,2,3,4}.
31 views

### Problems in animating graphs and its extrema

I tested to animate 2D graph and its extrema for simple case using Mathematica. ...
42 views

### Shared variable can not be distributed again after UnsetShared

I see a weired behavior in my MM 10.3 version. Can someone reproduce it or explain what is going on? The code is easy: ...
59 views

### Discrete Fourier Transform: help on how to convert x axis in to the frequency when I have a set of data samples [duplicate]

I have a huge data set (400000 sample) and when I plot them ListLinePlot[Au4, PlotRange -> {All, All}] I used the following code to Fourier transform it ...
53 views

### Product derivative on derivative [on hold]

this is a silly question, probably. How to product derivative on derivative in Mathematica. I mean for example how to achieve this result: Just more explanation. I need this for solving task with ...
261 views

### How is LHS = RHS; … ; LHS (nontrivially) different from … ; RHS

I'm trying to understand how Mathematica thinks about the results of Set. Suppose we perform LHS = RHS. I'm focusing on when ...
19 views

### Solving a simple ODE [duplicate]

I am trying to solve $y(x)' = \sqrt{y(x)}$ with initial condition $y(0)=0$ for $x\in \mathbb{R}$. I have tried this: DSolve[{y'[x] == Sqrt[y[x]], y[0] == 0}, y[x], x] but this gives {{y[x] -> ...
19 views

### Popup window shows after kernel closed when using J/Link

A popup window always show after kernelLink.close(); And this only happen after expression evaluated as graph. Such as ...
73 views

### A simple question about replaceall and plotting

I was trying to replicate the picture produced on the following Wikipedia page: https://en.wikipedia.org/wiki/Evolute with the astroid emerging as the envelope of normals to the ellipse. I ran into ...
46 views

### Riemann Zeta function definition was expanded by Euler with an infinite product series [duplicate]

The Euler infinite product series definition for Riemann's zeta function requires that Mathematica use all prime numbers in the product series. Can anyone help me with the code that will give a ...