4
votes
0answers
129 views

Efficient Generation of Subgraphs (or, unfriend a friend a day)

NB: If you're not interested in the back-story, you could simply jump forward to the code which I'm seeking to optimize. Also, I believe this code would only work for MMA 8.0 and above. My friends ...
4
votes
0answers
114 views

How can you link Parallel Mapping and Error tracking

Following this question and the comments made, together with the information in this question, the following code allows error tracking and debugging very nicely. ...
4
votes
0answers
170 views

Solving a nasty equation

Here's an equation that I need to solve for $t_k$ $$ \theta_0 = \tan^{-1}\left(\frac{2(w_x - m)}{p - g {t_k}^2 - 2 t_k w_y}\right) - {\frac{1} {r}} \left( \left(\frac{m}{t_k}\right)^2 + \left( ...
4
votes
0answers
607 views

Analytically solve the eigenvalue problem with infinite dimensions by Mathematica?

If I am given a symbolic expression of all the matrix elements in an infinite-dimensional space, e.g., the Hamiltonian of a quantum mechanical system, is it possible to get the symbolic expression for ...
4
votes
0answers
651 views

When using NMinimize[…,Method->“DifferentialEvolution”] is an “iteration” different than a “step”?

Hopefully this question has a simple answer. I have the following bit of code: ...
4
votes
0answers
604 views

looking for a generalised Hough Transform function or a least a function to locate circles

I am looking for a generalised Hough Transform function or a least a function to locate circles (position of center and radius) in a image. There is the standard Hough line search function ...
4
votes
0answers
345 views

Counting paths of a certain length between a source and sink vertex

I have a graph $G$, which may be directed or not, and I was wondering if there was an efficient way of using, say, BreadthFirstScan[] and FindShortestPath[] to count the number of paths between some ...
4
votes
0answers
203 views

Strange result from evaluating a Limit expression

When I evaluate the limit of (1-Cos[x]) Sin[1/x] at x = 0 in Mathematica 9, I obtained ...
4
votes
0answers
99 views

Is there a way to check whether two notebooks share the same variables?

When I code in Mathematica, I often re-use code from old notebooks which fulfilled a specific purpose; for example, one testing for soft matches in strings, or one that identifies outliers on a graph ...
4
votes
0answers
416 views

Cubic polynomial interpolation with velocities listed rather than some points

I am trying to use the function BSplineFunction[] to create a natural cubic spline. Normally what is done is that you specify "SplineDegree -> 3" and include a list of points and it will carry out ...
4
votes
0answers
151 views

Version 8.0 integrates but Version 9.0.1 doesn't

I am trying to run the following integral in version 9.0, but it fails: ...
4
votes
0answers
119 views

Proper treatment of roots and powers in Series?

I have the following problem in Mathematica 9 on Linux. I let Mathematica compute the Series expansion: ...
4
votes
0answers
95 views

Using Resolve and ForAll to prove takes a really long time

I've been trying to prove a lemma for my paper using Mathematica... basically that $$\forall \{n, d_i, d_j\} \in \mathbb{Z},\ n \ge d_i > d_j \ge 2$$ it's true that $$V[1, n, d_i-1, d_j-1] ...
4
votes
0answers
187 views

Possible to batch WolframAlpha queries?

Sometimes I want some country data not available from CountryData. And issuing things like: ...
4
votes
0answers
78 views

Problem with inequality using refine

I am using inequalities to follow some line of reasoning in Mathematica and I came across a problem I can not explain to myself. Does from a>=0 and b>=0 not follow a+b >= 0? How does Mathematica ...
4
votes
0answers
222 views

What's the kernel launch command syntax?

I want to configure a remote kernel, but the box it'll run on doesn't have a fixed hostname or IP address. I can however get its IP address by running a shell script. (For the moment I'm only worrying ...
4
votes
0answers
120 views

Symbolic solution to ODE, pure InverseFunction not evaluated

I'm new to Mathematica and I don't understand why in the solution of the following ODE, the #1 in the pure function is not immediately replaced by the corresponding ...
4
votes
0answers
123 views

How can I link the c library GAUL into Mathematica?

Is there a way to load the library GAUL (Genetic Algorithm Utility Library) for use within Mathematica?
4
votes
0answers
133 views

Why does $Path change when I examine it in new cell after I just changed it?

This is really driving me crazy. In one cell, I change $Path by removing from it un-needed paths that I do not want for the duration of a computation I will be ...
4
votes
0answers
257 views

Notebook manipulation to “Save as (HTML)”

In a previous question, I said that I wanted to display code as text in "Save as (HTML)". I am closer, but would like to ask the community for a better approach by telling the whole picture. I did my ...
4
votes
0answers
264 views

Why does OS X need permission to allow JLink connections each time it starts?

I understand that JLink loads each time Mathematica launches or each time a kernel starts, and that this can require permission from the firewall, if it is enabled but OS X provides settings the ...
4
votes
0answers
205 views

FinancialData property value at a given date

I was trying to get the volatility value of a specific equity on a given day. Based on the Mathematica Help, the syntax is ...
4
votes
0answers
502 views

Finding a Graph Shortest Path with Custom Graph Distance Function

What is the best way to find a shortest path by using a custom distance function? I'm trying to play a little bit with the concept of using distributions instead of a deterministic weight value for ...
4
votes
0answers
258 views

Second-Order Feedback Pathways

I'm relatively new to Mathematica and I've tried searching and reading through the Mathematica documentation but I'm not able to find a good place to start. I want to model a simple, second-order ...
4
votes
0answers
94 views

BipartiteMatching hangs with floating-point weights in Mathematica 7 (package Combinatorica)

I am trying to use Combinatorica's BipartiteMatching algorithm on a weighted graph. I need to use real numbers as weights. If I try the following ...
4
votes
0answers
291 views

Front-end glitch when interacting with dynamic content

This is now bugging me too much to ignore it anymore. When I interact with a notebook that has dynamic content, for example moving a slider, Mathematica regularly brings other open notebook windows to ...
3
votes
0answers
28 views

Why doesn't Mathematica evaluate solve numerical integral function when specifying range?

I'm having trouble getting Mathematica to solve equations numerically. I know that its important to specify the type of variables for pattern testing (see e.g. here) but this doesn't seem to work. ...
3
votes
0answers
37 views

VS c# NetLink - pictureBox - MathCommand

Has anyone experiance or a running example how to use within VS C# the NetLink.UI pictureBox to plot graphics, especially using the pictureBox - "MathCommand" I use the code example below which throw ...
3
votes
0answers
41 views

How to export to NetCDF format

Consider I have a scalar field on a grid f(x,y), where x and y can take values ...
3
votes
0answers
57 views

Refining a density plot of the Eisenstein series argument

Thanks to amazing code from "Guess who it is" here: Eisenstein Series in Mathematica? I'm able to make some nice plots using Eisenstein Series. What I'd like is a color plot of the argument of certain ...
3
votes
0answers
56 views

Possible bug in fetching price index data?

I seem only able to fetch price index data for the U.S. For example, the following fails (Mathematica 10.2): ...
3
votes
0answers
53 views

Method of characteristics, recursion formulas

I'm helping a friend out with a problem. He needs to plot out the solution to a water surge in a pipeline. I have all the parameters set and I've put the equations in Mathematica, but I can't get the ...
3
votes
0answers
52 views

How to speed up a high dimensional numerical integration of Gaussian-form integrand

My integral has the following form: $$\int \sin(\theta) d\theta d\phi\left| \int d^3p_1 d^3p_2d^3p_3 \frac{f(p,\theta,\phi)}{g(p,\theta,\phi)}e^{-\frac{1}{2}(p^\mathrm{T} .A.p)}\right |^2,$$ where ...
3
votes
0answers
47 views

Issues adding properties to multigraph

Today I was working with a large multi-graph with properties on the edges when I discovered that properties aren't assigned as expected. My preferred graph construction method is to specify ...
3
votes
0answers
29 views

Front end responds slowly when writing

I have Mathematica 10.1 running on a Windows 7 laptop (i7 processor, 64-bit system with 4 GB Ram). The issue is that when I type in commands the letters build up very slowly on the screen. E.g. when I ...
3
votes
0answers
79 views

Importing large number of frames form Video - improved method?

I am trying to work with large numbers of frames from a video (30000+). I see there are a number of answers out there, but I find none of them satisfying - see below for details. I understand from ...
3
votes
0answers
74 views

Change the background color of matched strings when doing find-and-replace

This is not a fundamental question, but it puzzles me. In doing a Find & Replace for some string in a notebook, the matched string is highlighted temporarily with some background color (green for ...
3
votes
0answers
38 views

Solve ItoProcess SDE

I specified a SDE for a random process $y(t)$ using ItoProcess is there a mathematica function that provides the analytic solution for $y(t)$? I know ...
3
votes
0answers
76 views

Mathematica 10.2 break downs when `StreamPlot`-ing

Bug introduced in 9.0.0 and persisting through 10.2 or later This code meets error: ...
3
votes
0answers
71 views

Solving for the roots of a trilinear system of polynomials

I have been trying to solve for the roots of the following system of trilinear polynomials: ...
3
votes
0answers
38 views

Changing scroll range for mouse wheel

Is there a possibility to change the range for scrolling with the mouse wheel in Mathematica? In ScrollingOptions I couldn't find such an option. I played around ...
3
votes
0answers
72 views

How to extract a Graph[] from an image?

This graph (as a picture) is given below: I am wondering rather than setting up this network graph using Mathematica syntax such as PathGraph,...
3
votes
0answers
55 views

How to produce timely spoken text?

On my system (Mac OSX 10.10.4) the following code produces only the first utterance. The second one is produce when the user interacts in some way with the front end (mouseover, mouseclick). How can I ...
3
votes
0answers
59 views

Where's the service status page for Programming Cloud?

I've searched wolframcloud.com and found none. It would be good to know, because I am getting a range of apparently random failures from "Tag List ... is Protected" to "possible crash" (!) to "Cloud ...
3
votes
0answers
42 views

Tracking features where ImageFeatureTrack finds none?

How is it possible to track common features in the following sequence of images (e.g. holes or corner points along the top margin), ? I have had no luck with ...
3
votes
0answers
39 views

Setting MaxIterations for neural network function `Predict`?

The neural network implementation of Predict seems to support a number of undocumented options as shown in a previous question: How to change NeuralNetwork ...
3
votes
0answers
46 views

String option names for Cells

They seem to be correctly interpreted. I'm asking because of some minor reasons and a major one: NotebookWrite a Cell with WholeCellGroupOpener option I don't know any official confirmation so let ...
3
votes
0answers
32 views

How to create permanent intra-notebook links

I'm trying to create a documentation notebook for a package and have entries which reference other entries. I'd like to include the hyperlinks in text formatted cells so that when a reader clicks on ...
3
votes
0answers
83 views

StreamPlot of potential flow from a finite element calculation

I am trying to calculate a potential flow past a thick plate. The finite element calculation seems to go well but I am finding it difficult to get a nice plot of the flow. The stages below are, ...
3
votes
0answers
66 views

Verification of results given by NDSolve

I am trying to solve a system of ODEs using NDSolve. The differential equations used are obtained by applying method of lines to actual governing equation. The system includes differential equations ...

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