# All Questions

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### Computation of Hankel Transform Rainer example

I found Rainer's answer to be perfect. However I would like to know if he could upload his code for calculating the propagation of optical fields (for example, to reproduce Fig.3 from the reference he ...
6 views

### How to copy Coordinates of “Get Coordinates” in Figure?

I am trying to reproduce the answer here about Recovering data points from an image. I click the figure and press "Get Coordinates". I would like to copy the four coordinates by CTRL-C and then paste ...
7 views

### Théorie de Fourier in Sontags book

I was reading Sontags In America and she mentions: "La théorie de Fourier sur les douze passions radicales.." What is this theorem about?
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### ParallelDo does not work, when using variables from other parts of the script

I have a script doing a large amount of calculations with very big matrices that takes so long; so, I want to parallelize pieces of the script to be executed on multiple kernels. For instance, the ...
14 views

### benchmark of Mathematica's FEM?

Does anyone have any numbers on how mathematica compares to other commercial (eg ANSYS) or free FEM softwares (eg. FreeFEM++, FEniCS, elmer)? If this is too vague say solving the diffusion equation in ...
12 views

### Bouncing a disk off a line

I have been working with this concept and have not been able to accomplish it yet. I am trying to have the disk slide to the determined location but if it hits the line it bounces off at the ...
2 views

### Complex number simplifications

My Mathematica notebook is not simplifying some expressions which do look trivial. I mean that one of my outputs contains: ...
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36 views

### CForm not getting exp(), pow, log() functions

I'm performing derivatives in Mathematica and I want to use them in a C code. For that, I'm using CForm as for example in this expression: ...
30 views

### function as argument in a package

I would like to customize the function DensityPlot and use it in a package as a function called MyDensityPlot: The functions ...
35 views

### How to speed up NDSolve?

I have a program where I need to iterate NDSolve thousands of times for different configurations of a diffusion problem. The thing is, I only need about 3 digits of accuracy. I looked thru previous ...
67 views

### Replace pattern for exponentials

Ultimately, I want to replace every Exp[(const) w[i,j]] to T[i,j] and Exp[-(const) w[i,j]] to 1/T[i,j] in the following expression ...
41 views

### Lyapunov exponent of non-autonomous differential equation

I am trying to calculate the Lyapunov exponent for a non-autonomous system using M Sandri code, but it always shows me error "infinite expression 1/0 encountered". Does anyone know about this? Mr. ...
33 views

### Maclaurin Series Help [on hold]

My problem is to numerically approximate the series (1 - Cos[x])/x over the interval [0,1]. I typed it into Mathematica as so: ...
39 views

### All Graphics3D commands crash

Recently updated from Mathematica 8.0 to 10.2 running on Windows 7 (8.0 was uninstalled before installing 10.2). Anytime a 3d graphics is rendered, the first rendering in a notebook is completely ...
27 views

### NDSolve kernel crash, affected by variable naming

The following isolated example cannot be further simplified much to reproduce a crash. I've already submitted the issue to TechSupport, but it seems this is not an easily reproducible case, so I'm ...
40 views

### Pumping Lemma - non regular [on hold]

Can everyone help me to show that: the language L = {a,b}* \ {a^m b^2 m a^n | m,n >= 0} is not regular. I don't know what is the meaning for the proof.
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### Input in Manipulate

Plot[Evaluate[ Input["Please input a function of x to plot with one parameter \ \[Alpha] to manipulate"]], {x, 0, 1}] This work without doubt. But ...
32 views

### Using TraditionalForm to express equations

I have a notebook in which a couple of partial derivatives are calculated. At the time of publishing this notebook, I'd like to make the resulting equations look the way they would in standard ...
25 views

### Bezier curves function in mathematica [on hold]

I need help urgently, for next monday I need to write the name ALAN using BEZIER CURVES programming it on mathematica, but I'm not allowed to use the bezier curves function that mathematica already ...
299 views

### Is there a way to make a bihistogram plot?

Is there a way of making a bihistogram plot in mathematica? There is a reference to it at http://mathworld.wolfram.com/Bihistogram.html but no suggestions as to how to do it.
51 views

### how to apply Alternatives command to delete cases from a list?

I have two lists let say listF = {{7, 2}, {2, 6}, {8, 1}, {1, 7}, {11, 8}, {6, 11}}; and ...
118 views

### Dynamical system problem x(t+1) = Ax(t)

I have a problem that have been trying to solve but it's not going so good. I would like some guidelines on how to work myself around this problem: Two neighboring countries spy on each other and ...
52 views

### How to calculate the slope in a data set plotted in ListPlot?

I am working with a large set of data that follows an exponential behaviour. My challenge is to create a function in Mathematica with these objectives: Retrieve the information from an Excel File ...
48 views

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