# All Questions

645 views

### Counting radial ridges on an image

After happily using the v9 image assistant to crop elliptically an image, and then the drawing tools to put a white disk in the middle, I turned this image: into the following one: that can be ...
2k views

### How to find the center of a circular pattern?

I am writing an algorithm that finds the center of 500 x 500 pixels images coming from a live feed from a camera at 50 Hz. So it has to be quick! The images are images of an optical field which looks ...
688 views

### Alternative ways to implement a triangular recursion

Triangular recursions are a class of algorithms that frequently turn up in computational mathematics. These recursions are expressible in the general form ...
747 views

### How would I improve this Karaoke machine code?

I was looking at a large collection of Import/Export user suggestions the other day and it dawned on me that we finally have MIDI import in Mathematica 9, which is rather interesting since MIDI ...
348 views

### How can I see which transformations Simplify attempts?

The documentation for Simplify[expr] says that it performs a sequence of algebraic and other transformations on expr, and returns the simplest form it finds. How can I see which transformations it ...
2k views

This question is based on the old song, The Twelve Days of Christmas In a comment made on a recent question, Yves Klett remarked, "no seasonal questions this year?" This reminded me of one I solved ...
5k views

### What are the advantages of using .nb rather than .m files?

I can edit a notebook within the mathematica front end and then Save As a .m file, which produces output like this: ...
1k views

### The Orbit and Perigee of the Flamsteed comet

Historical context This year we have the 330-th anniversary of the Battle of Vienna - one of the great formative events of European history, it took place on September 12, 1683. Kara Mustafa, Grand ...
1k views

### Removing In/Out Labels before printing

I know that I can close a notebook and open it again in order to remove the In/Out labels. What I would like to know is if there is another easy way of removing these labels without having to close ...
1k views

### Rotating perspective of an image in the z axis

A purely recreational question, but one I hoped the community would find interesting enough to suggest a way to approach it. Let me preface this question with the admission that I have done nothing ...
519 views

### NotebookFind and String Pattern Expressions

Is there a way that NotebookFind can be used to match string pattern expressions rather than just strings? The documentation for ...
635 views

### Nonlinear least squares on a GPU with Mathematica 9

Update: A Mathematica wrapper for (https://github.com/zitmen/cuLM) should allow for us to directly implement the Levenberg-Marquardt algorithm in CUDA for nonlinear least squares fitting. In a ...
556 views

### Paste data into Mathematica with formatting

Select the following Mathematica code and paste it into a notebook. In Windows 7(Mathematica 8) the line breaks are not interpreted in the expression. In fact any data copipasted from stackexchange ...
830 views

### Clustering a set of points

I have a set of 2D points in the square defined by {-1, -1} and {1, 1}. These points typically form compact groups. I need to ...
472 views

### How can I trace a functional expression's evaluation visually?

Ok, so the goal is to visualize the execution of this expression foo /@ {3 + 1, bar /@ {1 + 2, {4 + 7}}} in the following fashion using nested rectangles with ...
377 views

### Applying different functions to different columns of a Dataset

Suppose I have different functions: Total, Mean and Max and the following ...
2k views

### Edit a Mathematica plot in Illustrator, missing font problem

I export my Mathematica generated plot as an eps and then open it in Adobe Illustrator to make a few changes. When I try to do this I get this error message: Times-Roman: Font not found on ...
425 views

### Is it possible to insert new colour schemes into ColorData?

Because of the standards in my field, for many plots I need to use (or at least end up using) rather narrowly defined colour schemes, and in particular the Matlab "Jet" scheme, which is well described ...
870 views

### How to make a parallel auto-generated .m package from Initialization cells?

according to the documentation at ref/InitializationCell, When you first save a notebook that contains initialization cells, you have the option to make a ...
1k views

### WYSIWYG table creating and editing

In Microsoft Office OneNote 2010, creating and editing tables is easy. There are simple toolbar controls for creating tables: , and editing them once they exist: . My question is, what's an easy ...
758 views

### How to sort digits in a string while keeping other characters untouched?

Now there is a string with digits and letters, for instance, "95uge678r3gi89hgfe30kgh063d51". And the expected output is ...
323 views

### Combining BarChart and Grid - IPCC style

I would like to combine a plot with a table. Something like this famous plot/table from IPCC: So after reading Combining graphics & lists / tables I tried an approach using ...
589 views

### Block Matrix Algebra with Mathematica

I have come up with some BlockMatrix Algebra for Mathematica to make notations easier. I have the following: ...
2k views

### How to convert an image to a graph and get the positions of the edges?

I am trying to convert an image to a graph. My image is already skeletonized and looks pretty much like this: What I need to do is identify all vertices and edges, and in particular get a list of ...
514 views

### How to guarantee that NDSolve correctly detects abrupt changes in parameters?

When using NDSolve, I often have parameters that, in most of their domain, have a constant or null variation, but that suffer from abrupt variations on a very small ...
477 views

### Microsoft SQL DatabaseLink connection using Windows Authentication

For those who use Mathematica with databases in companies, a common way to securely connect to those is using Windows Authentication (detailed here). Mathematica doesn't seem to support this ...
3k views

I have a large Excel .xls file. Miniature version shown below: (formatting should appear as two columns...) ...
1k views

### Reference request for neural network programming in Mathematica

I'm looking for a good reference/book on programming neural networks in mathematica. I've been working through Freeman's "Simulating Neural Networks with Mathematica," but it is from 1994 so is quite ...
354 views

### Modify existing color scheme

I am using the "TemperatureMap" color scheme for image processing. How can I set the lowest color value to Black? Generally ...
602 views

### Determine frequency of oscillations

I am wondering how I could determine the frequency of oscillations of a differential model equation? How could I find the frequency from this example given in Mathematica Documentation: ...
939 views

### Enlarge an image and increase its resolution

An ongoing purely recreational project. I got my introduction to image processing with this Rotating perspective... question and had a lot of fun with it. Now I want to take it to the next step. ...
223 views

### How to use C language functions in Mathematica? [duplicate]

I'm trying to find out the way to use c-functions in Mathematica (I'm using 14 version) on OS X 10.10. For example I've got this lines of code: ...
970 views

### Mathematica code for hidden Markov models (HMM)

I am looking for some simple Mathematica code to model an HMM with just a few states and an equal number of observable signals (emissions). I am hoping to generate sample paths and keep track of the ...
263 views

### Avoiding MainEvaluate in a CompiledFunction to fetch global variables

I'm trying to write a simulation using Mathematica 8.0. Since I will most likely be doing the same operation over and over again, I'm trying to Compile whatever I ...
204 views

### How can I make Which format its output?

Functions like Piecewise have cool, easy-to-read formatting. In the same vein, I think it would be wonderful if the Which ...
621 views

### How to copy code out of notebook to an external text editor without extra line feeds being added?

I am simply trying to copy code from a cell (input cell) in a notebook, to paste the code into a plain text editor, and not have some lines wrap in the middle. I need to copy the code, as is, to a ...
1k views

### Rebinding keys to define new keyboard shortcuts

I've checked Mathematica → Preferences, and poked around the options on the toolbar. However, I don't see a way to define new keyboard shortcuts in Mathematica. I've used VIM for 10+ years, and I've ...
160 views

### How to use RunProcess to import external function?

I have a functions written in an external language called GO. How can I quickly load them into the kernel for use as Mathematica functions? The two ways I've tried are with MathLink and LibraryLink ...
219 views

### How can I add arbitrary code into DefaultKeyTranslations.tr?

The solution to this question on how to get latex code for a text cell (which Mathematica doesn't do correctly) was formulated as a palette but I need it as a keyboard shortcut. How can I add an ...
439 views

### Detecting double click events

Is there a way to detect double click events? I did not find anything on the doc page of EventHandler. Use case: I want to re-implement the ...
2k views

### Spiral pattern and Fibonacci numbers

I'm want to generate a 2D spiral pattern like the the one shown in the following figure. I can generate the spirals one by one, but I think there ought to be a more efficient method for generating ...
1k views

### How do you draw credible regions/intervals on a 2D PDF?

I have some numerical data from which I generate a PDF via: pdf = HistogramDistribution[data]; Which can then be easily visualised thus: ...
2k views

### Doing a chi-square independence test in Mathematica

I have a matrix consisting of the following data: Needs["HypothesisTesting`"] data = {{11, 206}, {32, 1374}} How would I make a chi-square independence test ...
9k views

### Plot legend inside a Show [duplicate]

Possible Duplicate: Using PlotLegends with Show messes up the graphics I have created a composite plot function: I want to add a legend to it, but ...
1k views

### No warning when extrapolating with Plot

One of the most annoying "features" of Mathematica is that the Plot family does extrapolation on InterpolatingFunctions without ...
2k views

### Mathematica 10 Notebook Fonts Look Bad

Bug introduced in 10.0.0 and persisting through 10.0.2 or later I've upgraded my home installation of Mathematica from version 9 to 10 today on a Windows 8.1 machine, and I'm getting a weird font ...
296 views

### Random polyhedra walk

I would like to recreate ssch's random polyhedra random walk, which he posted in the chat. For convenience here it is again: Since it's been one and a half year since then I've certainly had time ...
2k views

### Will Mathematica install and run on Raspberry Pi computer?

My club is considering buying a Raspberry Pi computer for tinkering. Can Mathematica be installed on and ran from it?
How to write beveled fractions like ${}^a/_b$? In contrast to $\frac{a}{b}$ and $a/b$ (see this question).