# All Questions

178 views

### Rule transformation between letter and number

I have a global rule as follow: ...
509 views

### Is FrameTicks broken in 10.1.0?

On my system, Mathematica 10.1.0 under Windows, none of these FrameTicks documentation examples work correctly: ...
427 views

### AltGr randomly stops working - Windows 7

My problem is that AltGr just randomly and frequently stops working. I've only seen this problem since the last update (10.1). The only sure way to recover functionality that I've found was to change ...
46 views

### How to adjust the FrameTicks length in DateListPlot?

suppose I have the data for DateListPlot: ...
64 views

### Covariance matrix estimation when number of variables is larger than number of observations

It is well known that the sample covariance matrix estimator results in a singular matrix if the variables is larger than the number of observations. One solution is to apply shrinkage estimators. ...
88 views

### How to define $x^n$ where $x=\pm 1$ and $n\in\mathbb{Z}^{+}$?

I do not know how I can define $x^{n}$ in Mathematica, where $x=\pm 1$ and $n=1,2,3,\ldots$. For even values of $n$ we simply have that $x^{n}=1$. While for odd values of $n$ we have that $x^{n}=x$. ...
84 views

### speed up evaluating a listable function [duplicate]

I apologize in advance for the vagueness, but I can't think of a more descriptive title. I am trying to find the average value of the square of BesselJ[0, x] ...
499 views

### Exporting Dataset to WDX format fails

I reported this to WRI support. Tracking number is CASE:3368636 Official answer is: Thank you for contacting Wolfram Technical Support. This is a known issue and our developers are working on a ...
117 views

### Importing a spreadsheet with infinity values from Excel

I have imported a spreadsheet from Excel that I want to use as an adjacency matrix. I want to use this matrix as the argument in WeightedAdjacencyGraph, so I have ...
40 views

### SetOptions does not give expected result with Grid [duplicate]

Chech this example: ...
151 views

### DiscretizeRegion of ImplicitRegion too small

I have a 2D function that has some sharp peeks within the my domain. I need to find a tight region that contains these sharp peeks. The following is an example of what I would like to do. An example ...
54 views

### Defining a function which takes lists as it arguments and threads over them [closed]

I want to define a function with lists as variables, which has the form like m = Table[2, {i, 5}]; f[x_, y_] = m*x + x*y; x and y are list variables; m is a ...
242 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 ...
416 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 ...
97 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 ...
321 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.
222 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 ...
108 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 ...
282 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 ...
68 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: ...
180 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 ...
423 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 ...
85 views

...
112 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 ...
233 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 ...
166 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 ...
148 views

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

Considering we have a an association: ...
232 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 ...
157 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 ...
171 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: ...
125 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. ...
805 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 ...
208 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. ...
157 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. <...
109 views

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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. ...
64 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 ...
108 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 ...
337 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 ...
65 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]...
140 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 (...
112 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?