# All Questions

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### Series Expansion of Differential Operators [duplicate]

We know about the possibility of series expansion of a function in Mathematica. Same as below, where a function f[a x] is expanded around zero up to 5th order. ...
317 views

### Stream plotting in polar coordinates [duplicate]

I got to a scalar field that really looks just fine to me in polar coordinates. "looks just fine" = all the physical limits make sense. The scalar field in polar coordinates r and θ is: ...
242 views

### The envelope of a set of translated and rotated ellipses

I achieve a dynamic graphics by using Manipulate as follows: ...
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### How to multiply lists of data?

Let two lists of data, say lst1={{x1,y1},{x2,y2},...,{xn,yn}} lst2={{x1,z1},{x2,z2},...,{xn,zn}} I need to construct a third list ...
150 views

### Incorporating photos into a Mathematica-made web page

I use Mathematica to make my web page. I make various .nb files, usually with photos, and then use an Export command to convert the .nb file to an .html file with ...
58 views

### FindShortestPath does not work

The FindShortestPath doesn't work in this graph, can someone tel me what's wrong? ...
312 views

### Print all numbers from a sequence which don't contain the digit 7

so i have this: Cases[RecurrenceTable[{a[n + 1] == 7 a[n] + n, a[1] == 1}, a, {n, 7}], Except[7]] But i noticed that it will only exclude numbers that are 7, and ...
98 views

### Calculating Variance (without Variance expression)

I am learning Mathematica on the fly, one of my tasks is to find the variance of white noise. I followed the tutorial for finding white noise by using the code: ...
131 views

### How can I copy and paste my beautifully indented code into my notebook without alteration?

Say I indent my code like this: ...
46 views

### Behavior of custom file chooser code changes when placed inside DynamicModule

My primary objective is to build a file chooser that aides a user in selecting files into one of two categories. Files can be individually selected, or based on the clicking of a specific checkbox, ...
154 views

### A peculiar behavior of NSolve[]

NSolve[Power[x + 1, x + 1] - Power[x, x + 2] == 0, x, Reals] returns: {{x -> 3.14104}} Great. However, ...
336 views

### Compute a hessian matrix on a image?

Is it possible for Mathmatica to load a gray image and apply a hessian matrix on it?... It used image processing to find good features.
87 views

### Orthogonality relations of Hermite polynomials

The Hermite polynomials are orthogonal. $$\int_{-\infty}^\infty H_m(x) H_n(x) e^{-x^2}\, \mathrm{d}x = \sqrt{ \pi} 2^n n! \delta_{nm}$$ Does Mathematica not use this relationship? Because running ...
268 views

### Taylor series representation as an infinite sum

I want to see the Taylor series representation for arbitrary functions, e.g. $\sin$. With the Series[] command, I can only see the first $n$ terms. Is there the ...
375 views

### Projection of triangles onto a sphere

I am trying to find the solid angle taken up by a large set of triangles around a central point. I have normalized the vertices of the triangles to a unit sphere around the central point, But the ...
92 views

### Symbolic matrix calculation [closed]

I have question about a matrix calculation like $\mathbf{b}^{t}\,\Sigma\,\mathbf{b}$, where $\Sigma$ is a 7 by 7 matrix, and $\mathbf{b}$ is vector of 7 elements, and each element in the vector ...
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### Is there a programmatic equivalent of Edit > Find…?

Most things that can be done via the front-end interface in Mathematica can also be accomplished by some function. Is that the case for find-and-replacing? That is, is there some code I could execute ...
152 views

### The idea behind Stiffness switching method with NDsolve [closed]

Does the Stiffness switching method with NDsolve switch just between multiple variants of 4th order Runge Kutta method or it uses also other methods?
131 views

### Integral too oscillatory

Is there any way top make this integral less oscillatory? ...
210 views

### Binary file gymnastics

I have an unformatted binary file generated by fortran 77 and i want to import it in Mathematica. The file is formed by 5 data arrays with double precission float numbers. The problem is that seems ...
68 views

### How to keep elements only if their first key is part of another list? [duplicate]

I have two huge lists: list1 and list2. I would like to keep elements of list1, only if ...
128 views

### Divergence in spherical coordinates as can be done in W|A

Is there any widget kind of thing that can work out calculations of vector analysis in not-Cartesiian coordinates, i.e spherical and cylindrical? Like the calculators found here: ...
35 views

### How to close the debugger window [duplicate]

So this thing just popped out of nowhere X.x ... I tried getting rid of it yesterday following suggestions in this post and I could've sworn it went away. But today I opened my laptop and the damn ...
329 views

### $\mathbf L\mathbf D\mathbf L^\top$ Cholesky decomposition

Mathematica can do a Cholesky decomposition $\mathbf A = \mathbf L\mathbf L^\top$, but how do I do a LDL decomposition $\mathbf A = \mathbf L\mathbf D\mathbf L^\top$, with $\mathbf L$ being a unit ...
73 views

### Computing large nested values

Is it possible to compute a value for n=10^9; Nest[# + Log[#] &, 2., n] for large n? $10^9$ seems to be the max for me - ...