7
votes
1answer
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 ...
13
votes
4answers
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 ...
4
votes
1answer
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 $r\to-r$. ...
6
votes
1answer
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. ...
8
votes
1answer
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 ...
7
votes
4answers
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 ...
3
votes
1answer
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.
1
vote
1answer
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 ...
1
vote
1answer
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 ...
2
votes
1answer
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 ...
11
votes
3answers
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 ...
0
votes
0answers
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 ...
1
vote
2answers
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: ...
5
votes
1answer
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 ...
9
votes
1answer
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 ...
1
vote
3answers
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: ...
2
votes
1answer
118 views

Three questions about two plots

I used the following code ...
0
votes
1answer
84 views

How to change sign among eight octants

...
0
votes
1answer
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 ...
16
votes
2answers
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 ...
3
votes
1answer
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 ...
3
votes
3answers
146 views

How to check keys and values in nested Associations?

Considering we have a an association: ...
21
votes
1answer
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 ...
0
votes
2answers
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 ...
2
votes
2answers
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: ...
2
votes
1answer
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. ...
12
votes
2answers
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 ...
1
vote
1answer
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. ...
9
votes
1answer
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. <...
2
votes
1answer
107 views
1
vote
1answer
46 views

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. ...
2
votes
0answers
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 ...
4
votes
1answer
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 ...
8
votes
2answers
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 ...
-1
votes
1answer
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]...
6
votes
1answer
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 (...
3
votes
1answer
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?
1
vote
2answers
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 ...
3
votes
0answers
47 views

TimeSeriesInsert issue with Quantity expressions

Solved in Mathematica v10.3 This first sample code works as expected: ...
10
votes
3answers
205 views

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

I have a ragged Association of Association, say : ...
0
votes
1answer
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 ...
1
vote
0answers
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) ...
7
votes
1answer
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: ...
7
votes
5answers
636 views
4
votes
1answer
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 ...
7
votes
1answer
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 ...
13
votes
1answer
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 ...
1
vote
2answers
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 ...
3
votes
2answers
447 views

Using periodic boundary conditions in NDSolve

I need to solve a 2D linear elliptical equation in polar coordinates using NDSolve, but I can’t seem to get Mathematica to accept the required periodic boundary conditions. My actual differential ...
5
votes
2answers
105 views

Locator-based abscissa ranges widget

I'm trying to implement a widget that will enable users to graphically determine certain abscissa ranges in a 2D plot. I've started by coding a prototype, whose output looks like this: The idea ...

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