# All Questions

232 views

### Finding the least positive integer satisfying a quantified statement

I'm studying the convergence of the sequence of functions $f_n:[0,1]\subset\mathbb{R}\to\mathbb{R}$ defined by $$f_n(x)=n^2x(1-x^2)^n$$ for $n\in\mathbb{N}$. These functions converge pointwise to the ...
410 views

### I have the minimum Y value. I want to find the corresponding X value from the list [duplicate]

I have a very big file and contains data in the format of {x,y}. I got the minimum Y value by using data[[All, 2]] // Min[#] & Now I want to get the X value ...
95 views

### NDSolve returns asymmetric solution to a symmetric equation

I am trying to find the potential of a conducting cylindrical electrode by solving the Laplace's equation. Both, the boundary conditions and the equation are symmetric w.r.t. the change $r\to-r$. ...
99 views

### Slow-down encountered for RandomChoice in large lists

I was wondering if anyone could help me to speed up this code snippet which creates simple (sparse) networks by preferential attachment. The algorithm adds a vertex and an edge each time interval. ...
96 views

### Filling Stacked Graph v.10.1

I used a code very similar to the code posted by Kuba stacked line graph with fragmented data ...
225 views

### Create Nested List from tabular data

Im trying to create a nested list from tabular data, then onward into a nested association. I can get part way with the help of this answer but it only works for the first level. Repeated use of this ...
304 views

### Partial fraction expansion with complex numbers

$$\text{Apart}\left[\frac{1}{x^4+1}\right]$$ Does nothing. How can I get it to expand it. Sometimes it is useful.
213 views

### How can I draw a box with moving particles inside and a hole in one side? [closed]

The idea is to create a simulation for ideal gas motion in a container that have a hole and then find the speed distribution for the gas particles that leave the box through the hole. I have a ...
105 views

### How to plot two random functions (Together)

I have ploted the next following jump diffusion model using Mathematica 10 $$X_t=X_0 e^{\sigma W_t+(v-\sigma /2)t}(1+J_1)\cdots(1+J_{N_t})$$ namely, a Geometric Brownian motion with compound Poisson ...
134 views

### NDSolve-Problem (Calculating field lines)

I want to calculate the field lines of a quite nasty vectorfield. In general the method works fine - except, one of the components of the VF gets 0 - then NDSolve ...
277 views

### Adds a rug representation to plot

This question came to me when I read How convert list of numbers to list of points on x-axis? @Mr.W suggested Interlacing a single number into a long list for the question. @Artes provides a very ...
92 views

### Replacing function in Sum

I have this expression, which, after execution, gives these $F[s,r]$ in output. $$S_{1,1}=\sum _{s=1}^{16} \sum _{r=1}^{16} F(s,r) \text{Tr}\left[G_r.G_1.G_s.G_1\right]$$ Here is a piece of ...
67 views

### Using Apply on a function with multidimensional input

I have a user defined function which takes multidimensional input, e.g a function that takes two algebraic variables a and b as well as a matrix m and computes some rule function as: ...
171 views

### Set PlotTheme globally?

Can one set a default PlotTheme globally? While I recognize one can make lots of workarounds to sort of do this: Go to ...
401 views

### Isometric perspective for Graphics3D

Is it possible to render Graphics3D in an isometric projection? I know that the ViewPoint option can be used for orthogonal ...
64 views

### Controlling the evaluation of other arguments in pure functions [duplicate]

I have a piece of code where I would like to do the something like the following: ...
118 views

### Three questions about two plots

I used the following code ...
84 views

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111 views

### Combine ListLinePlot and ListPlot3D using Graphics3D

I want to plot something very similar to what is plotted by @Sjoerd C. de Vries in Can 2D and 3D plots be combined so that the 2D plot is the bottom surface of the 3D plot boundary? I need to combine ...
228 views

### HDF5 importing large arrays

I have some computations that output a 300,000,000 element array of long unsigned ints, so about 2.4GB, in an h5 file. Mathematica handles files south of 2GB fine, albeit taking very long to import ...
163 views

### Mathematica error code 0x00000171

I'm getting above error code with a Trap 132 indication when attempting an ArrayPlot of a complex 130000 x 2048 matrix. Using Mathematica 9.0.1 with Mac OS 10.10.3 ...
146 views

### How to check keys and values in nested Associations?

Considering we have a an association: ...
227 views

### Is there any Mathematica functionality enabling its use for the blind?

A colleague of mine has become blind as the result of a sudden medical misfortune. We want to help him to feel useful and active again. We, however, still cannot determine what can be done and to what ...
154 views

### Solve returns empty list / running forever

Update: I made a mistake before and corrected the sign in code below in case people wonder what some comments mean. Thank you for those who answered. But I should have said that this is only part of ...
164 views

### Why does Mathematica not evaluate the difference recurrence using RSolve or RecurrenceTable?

Mathematica does not evaluate the following recurrence of two variables using RSolve and only echoes the input: ...
116 views

### How to apply different colors to different contours

I have searched the forum, I hope this isn't a duplicate question. I try to apply unique color for every contour line with the same elevation. In short, I want to create a MATLAB style contour plot. ...
798 views

### How to fill the space outside of an image after rotating it

I want to rotate this image by -50 degrees, and then fill up the black space around the rotated image with a bluish color. I can't find any documentation/answers that suggest how to do it. (Sorry ...
205 views

### Modeling a stellar atmosphere

I'm trying to model a stellar atmosphere using Mathematica. Basically I'm working in a physical and chemical model which combined should give me a profile of the chemical abundance in the atmosphere. ...
154 views

### Region computations on FilledCurve (with hole)

How can I obtain a precompiled RegionMemberFunction for this geometry? It contains a hole, and the hole's boundary intersects the outer boundary at one point. <...
107 views

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### CellEventActions not working within DynamicModule

So here is some code that successfully displays a slider, the value of a dynamic variable, and cycles through a list of 10 images titled 'imgs' with keyboard commands. ...
63 views

### Ubuntu: Dynamics are not working after suspending system

I'm working on Ubuntu 14.04 LTS 64-bit and I'm running Mathematica 10.1. Usually, I don't turn my computer completely off but I'm using the Suspend function which is AFAIK a suspend to RAM. After ...
101 views

### WhenEvent used in a PDE to output independent variable

I want to use WhenEvent with a PDE after it has reached steady state. I'm posting a system of 2 equations (my real system has 6) and I'm solving the advection-diffusion-reaction 2nd order PDE. First ...
326 views

### How to copy and paste $n$ lines from a text editor to $n$ cells?

If I copy from an external editor to Mathematica notebook a block of lines (with a code) line 1 line 2 ... line n then whole text is copied to a single cell. I ...
63 views

### Need help plotting multiple functions [closed]

a = 0.5 b = 0.33333 r = 1.5 e = -0.33333 f = 1 g = 1 m = 0.00001 n = 0.33334 o = 0.00001 p = 0.000003 DSolve[{ x'[t] == a*y[t] , y'[t] == -bry[t] - x[t] - e - f + g*y[t], z'[t] == m*(x[t]...
139 views

### Draw from a given list according to empirical distribution

I have two lists, where each time I have age-income vectors. Given the distribution of age in the first list, I would like to draw a sample with the similar distribution of age from the second list (...
109 views

### Extracting a time series from a sound object

After importing a sound file, how can I generate a time series (preferably as an $n\times 1$ matrix) which gives the intensity at equal time intervals?
80 views

### InverseWaveletTransform of a list of rules

I want to extract coefficient images from a DiscreteWaveletTransform and replace them by modified images of the same dimensions. However, when I use ...
47 views

### TimeSeriesInsert issue with Quantity expressions

Solved in Mathematica v10.3 This first sample code works as expected: ...
205 views

### Association of Associations : how to permute level 1 and level 2 keys?

I have a ragged Association of Association, say : ...
311 views

### Traces of products of Gell-Mann matrices in FeynCalc

I am working on an assignment in FeynCalc and I need to evaluate traces of products of two commutators of Gell-Mann (SU(3)) matrices, i.e. I need to calculate the ...
80 views

### Mathematica does not recognize RegionPlot3D? [closed]

I've been desperately trying to graph a 3D region fitting the following three inequalities: -x <= z <= x -y <= z <= y (x-y)/2 <= z <= (x-y) ...
108 views

### Way to add a same option to multiple functions

Just wanna figure out if there is a decent way to add a same option to multiple functions simultaneously. For example I have a series of SoundNote: ...
636 views

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311 views

### Smoothing a unit step function

I want to smooth a unit step function for use in NDSolve so this function is a smooth function of time (t). How can I do the ...
421 views

### Plotting iterated function system images

I'm new not only to this forum, but to Mathematica in general, evidently. I'm running into an issue, and my best attempts at Googling solutions (and trying the search box for this forum) came up with ...
478 views

### Any solution to transfer data between Python and Mathematica

I think Mathematica handles .mat file not very well, python is pretty good at this kind of jobs. In this site, there are plenty of question related to calling Mathematica from Python, or calling ...
234 views

### Plotting data from multiple text files

I'm new to mathematica and stack exchange, so any help would be appreciated. I want to plot a bunch of data from text files that contain a lot of extraneous data. I have a hundred files with different ...