0
votes
0answers
37 views

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. ...
1
vote
1answer
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: ...
10
votes
3answers
242 views

The envelope of a set of translated and rotated ellipses

I achieve a dynamic graphics by using Manipulate as follows: ...
6
votes
4answers
238 views

Constructing a grid from a matrix

I would like to construct a grid from a matrix. For example, one possible matrix is $M1$. $$M1= \begin{pmatrix} c2 & a1 & a1 & a1 & a1 & a1\\ a2 & b1 & c2 & a1 & ...
2
votes
1answer
89 views

Plot directional field with a initial vlue

I do not have enough reputation to comment on other questions, hence I have to ask my own one I want to solve the following nonlinear first order ODE, $$(1 + x) (0.5 y[x]^{-0.5} (x - y[x])^{0.5} - ...
6
votes
4answers
221 views

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 ...
7
votes
0answers
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 ...
-2
votes
1answer
58 views

FindShortestPath does not work

The FindShortestPath doesn't work in this graph, can someone tel me what's wrong? ...
2
votes
4answers
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 ...
1
vote
2answers
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: ...
1
vote
1answer
131 views
0
votes
1answer
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, ...
2
votes
2answers
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, ...
3
votes
1answer
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.
3
votes
0answers
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 ...
4
votes
2answers
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 ...
0
votes
2answers
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 ...
0
votes
1answer
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 ...
1
vote
3answers
172 views

how to create, print and use variables using a loop in Mathematica?

I want to create, print and be able to use (i.e. do symbolic operations) variables in Mathematica using a for loop or equivalent. So, I have a bunch of variables of this form: $$dS_i = -\beta_i ...
1
vote
1answer
59 views

Button labels in different platforms

if someone has Mathematica on a mac or a Linux system, could you please evaluate this code: ...
3
votes
2answers
139 views

Table of contents in the same notebook

I created TOC programatically using instructions from http://reference.wolfram.com/language/AuthorTools/tutorial/MakeContents.html But it created second notebook TOC.nb. Is it possible to create ...
0
votes
1answer
67 views

NDSolve::bcsol?

I'm writing a code to numerically solve a differential equation. It has to repeat the process several times since there is a variable involved which is unknown, and the equation is fit to some ...
4
votes
0answers
139 views

Mapping Images in Parisian metro stations

One particular aspect of some Parisian metro stations is that stations' walls are curved, even in the sides where one would place advertising posters. Here is a picture of one such station: I was ...
1
vote
0answers
44 views

Shortcut to call recent inputs [closed]

I am familiar with CTRL+Shift+L to call the last input; however, in the case that I want to, for ease-of-comparison, want to print outputs of a command from further in the past and don't remember ...
0
votes
0answers
70 views

Integration is unevaluated analytically after a variable removed

I am using Mathematica 9.0 to do a symbolic integration as follows: ...
2
votes
1answer
198 views

Plotting a pencil of lines

I want to plot a pencil of lines between line1 and line2 using a formula (alfa*(ax+by+c)+beta*(a1x+b1y+c1)), but it doesn't show me anything. ...
0
votes
3answers
142 views

How to take dot product of every element in a list?

I have a list of coordinates (coord): ...
1
vote
2answers
166 views

Simulation of LogNormal process for an asset pricing

I'm new to Mathematica programming, so forgive my rather unsophisticated question. I need to simulate 5000 "walks" of a process value (of a stock) that starts from its current value, at ...
0
votes
1answer
71 views

Strange long time evaluation of Series for fractional function

my problem concerns the Series command applied to a product of a rational function times a square root. This can be exemplified in the following way ...
4
votes
0answers
47 views

Odd behavior of FindFile

Running FindFile gives some odd results on my machine: FindFile["HTTPClient`"] Result: ...
-1
votes
1answer
137 views
2
votes
1answer
92 views

Part specification error with InterpolatingFunction when generating a Markov Modulated Poisson Process

I want to create a Markov Modulated Poisson Process, where the arrival rates created by the states of a ContinuousMarkovProcess are fed into an ...
2
votes
1answer
244 views

How do I get the adjacency Matrix from a random graph [closed]

I am using the command g = RandomGraph[{8, 13}]; GraphPlot[g, VertexLabeling -> True] to plot a random graph with n nodes and l edges. Once the program has ...
0
votes
1answer
115 views

Plot a function based on the value of another function

Could anyone guide me on how to plot the function VR with the values of ρ that I get from solving the following eq. ...
10
votes
4answers
284 views

Handy / flexible directory tree operations

Is there any shorter / more handy / more flexible way to get directory tree as a nested Rules/Associations list? I tried to incorporate ...
1
vote
1answer
52 views

Conditional Drop of a Key based on a test of the Value

I want to restructure a simple dataset. ...
0
votes
1answer
81 views

Symbolically solve system of equations involving matrix

I need to solve the following system of equations symbolically for a_i, b_i, and c_i: ...
0
votes
0answers
55 views

Some unexpected behaviour with StyleKeyMapping

Start with a fresh front end & kernel. The expected behaviour with an Input cell should be like this: Input 1and delete ...
1
vote
1answer
127 views

Extract coefficient matrix $A$ from expression $f(x)$

I have expression: $$f(x)=\sum_{i=0}^{K-1}\sum_{j=0}^{N-1}a_{i,j}e^{ix}x^j.$$ I want to extract coefficient matrix $A$ from expression $f(x)$ where $$A=\left( \begin{array}{ccccc} a_{0,0}& ...
11
votes
1answer
279 views

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 ...
2
votes
0answers
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?
1
vote
2answers
131 views

Integral too oscillatory

Is there any way top make this integral less oscillatory? ...
2
votes
1answer
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 ...
0
votes
2answers
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 ...
0
votes
1answer
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: ...
0
votes
0answers
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 ...
9
votes
2answers
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 ...
2
votes
1answer
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 - ...
1
vote
0answers
96 views

Calling a custom function in slave kernel process connected through mathlink [closed]

I am performing a small experiment to check if we can call/execute a custom package function in slave kernel launched from master using mathLink. I have created a dummy application called ...
2
votes
1answer
47 views

Modifying generalized input so there is no default input

I'm currently working on a demonstration and attempting to utilize the Interpretation command based on the example provided in the "Generalized Input" tutorial ...

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