15
votes
2answers
690 views

How to define a non-standard algebra in Mathematica?

I want to define an algebra, where there are three elements: 0, 1 and $\infty$ and two operations, addition and multiplication defined, both commutative: $$\begin{align*} 0+0&=0\\ 0+1&=1\\ ...
14
votes
12answers
608 views

Join lists with nested list

Is there a way of smarter way of joining list of the form l1 = {a,{b,c}}; l2 = {d,{e,f}}; l3 = {g,{h,i}}; To obtain ...
14
votes
6answers
561 views

How can I suppress rotation of 3D graphics?

Given a 3D image built of a combination several Graphics3D objects, is it possible to suppress rotation of the displayed image by the mouse? To be specific, here ...
14
votes
5answers
1k views

Make legend same height as plot

One common style for density plots is to have a vertical legend that is the same height as the plot itself. Some example density plots from Google Image search: How can we make DensityPlots with ...
14
votes
1answer
582 views

Detecting and counting signals in list data: checking pulse rate

Hope this isn't too much of a basic question: I'm looking for some Mathematica functions, but I don't know which ones. Background I recently read about a simple technique for reading your body's ...
14
votes
2answers
1k views

How to deal with complicated gaussian integrals in Mathematica?

As we know, for most Gaussian integrals, we can get the analytical result. Now I have many Gaussian integrals to treat, which have the following general form, ...
14
votes
4answers
404 views

How can we implement “Sleep Sort”?

Inspired by Implement Sleep Sort: Sleep Sort is an integer sorting algorithm I found on the Internet. It opens an output stream, and for each input numbers in parallel, delay for the number ...
13
votes
1answer
402 views

Morphological Filtering in 3D to produce skeletons

Context As a follow up of this question and that answer, I would like to identify the special lines separating 3D watersheds. These are useful in the context of astronomy to identify the ...
13
votes
0answers
1k views

Mathematica performance on Mac

I recently got a trial version of both Mathematica 9 and MATLAB 13a for Windows. I was stunned by the performance difference in the Windows and the Mac version. It was a simple test in matrix ...
13
votes
1answer
458 views

Get the current iteration count

I would like to be able to get the current iteration count, the one that if exceeds $IterationLimit makes the evaluation stop. After not finding a magical variable ...
13
votes
6answers
661 views

How can I fill-in this Pentagram?

This is my code: Graphics[{EdgeForm[Yellow], Yellow, Polygon[Table[{Cos[t], Sin[t]}, {t, 0, 4 π, (4 π)/5}]]}] which gives this: but I want to get: How?
13
votes
4answers
1k views

Is there a Mathematica/Lisp link?

I'd like to start learning Lisp as it sometimes leads to interesting answers on this site with concepts borrowed from this language, so I'm curious. As I already spend most of my programming time in ...
13
votes
2answers
436 views

How to REALLY Hold arguments and capture FullForm?

I'm trying to write an expression deconstructor or FullForm-capturer; might even call it a parser, maybe, but that might be too glorious a word. I got some great ...
13
votes
4answers
1k views

Is there a way to Collect[] for more than one symbol?

Oftentimes you find yourself looking for polynomials in multiple variables. Consider the following expression: a(x - y)^3 + b(x - y) + c(x - y) + d as you can ...
12
votes
3answers
353 views

Disentangling the data

An experiment yields a functional dependence on two variables $F(x,y)$, can be imagined as a 2D map. It is known that the function can be factored as follows $F(x,y)=fx(x) gy(y) +gx(x) fy(y)$. Given ...
12
votes
2answers
207 views

Bug with SparseArray selector in Pick

I have created a notebook with two cells. This is the content of the first: ...
12
votes
3answers
393 views

How to memoize a function with Options?

Consider the following modified fibonacci function: ...
12
votes
4answers
2k views

How to select and delete all Output cells?

How to select and delete all Output cells in multiple notebooks programmatically without needing to (manually) opening them? How to define a hot key for deleting all Output cells within a notebook ...
12
votes
1answer
2k views

3D plots with parallel projection

It is easy to make 3D Plots with Mathematica, e.g. use: Plot3D[Sin[x+y^2],{x,-3,3},{y,-2,2}] But I want to have nice plots in my thesis, so I decided to use ...
12
votes
2answers
524 views

Calculating morphometric properties

Is it possible to calculate segment length, segment diameter and branch angles for three dimensional geometry. Geometry contains vertex points and polygon surfaces as ...
12
votes
4answers
462 views

How do you decompose a polynomial matrix into its matrix coefficients?

Let's say I have a matrix, $\mathbf{M}$, that is polynomially dependent on a single variable, such as M = {{15 + a^2, a + 5 a^2}, {a - 5 a^2, 2}} and I want to ...
11
votes
5answers
308 views

Applying a function to a Dataset column conditional on another slot's value

How to apply a function to a column conditional on another slot's value? The Dataset documentation show only how to apply a function to named slots independently. The ...
11
votes
4answers
293 views

Dataset: get number of levels and elements

The summary box for Dataset objects shows the number of levels and elements at the bottom. How can we get these values programmatically? For example, "4 levels, ...
11
votes
2answers
425 views

Hatched Filling for ListPlot

I am plotting to data curves using ListLinePlot. I like the look of Filling, but this is going to be printed, so I want something both black and white friendly, but giving more definition and ...
11
votes
4answers
303 views

Replacing parts of a held expression with held parts of another expression

I'm applying the Trott-Strzebonski technique in order to replace inside a held expression. ...
11
votes
1answer
285 views

Is there a guideline about when to end expressions with semicolons?

Whether for nested Ifs or within scoping constructs like Module and Block, I never know ...
11
votes
2answers
597 views

Automatizing PSfrag export

I'm in the early phase of creating a Mathematica function (or package) that exports graphics such that they can be used with $\LaTeX$'s PSfrag. The goal Ideally, the function should take a graphic ...
11
votes
4answers
839 views

data clustering

I have some data set which i would like to partition into 3 groups a:set 1 b: set 2 c: background. I use FindClusters[] function but as you can see (after ...
11
votes
2answers
261 views

ShearingTransform and Dynamic

Background: I have a geometric transformation composed of a RotationTransform, ScalingTransform and ...
11
votes
4answers
4k views

How to change default notebook background color?

How does one change the default notebook background color?
10
votes
3answers
410 views

Generating hatched filling using Region functionality

Before v.10 came out there were several Q&A on generating hatched filling for Plot, ListPlot etc. In v.10 we have new ...
10
votes
3answers
477 views

Find intersection points with V10

My question departs from this one: Find intersection of pairs of straight lines but now I want to find the points with the new V10 Region-functions. ...
10
votes
2answers
369 views

Select cases from a list

I have a list in the form : {1,1,1,0,-1,-1,1,1,1,0,0,0,0,-1,-1} No I'm trying to select only those sequences which start with 1 have a zero (or many zeros) ...
10
votes
2answers
349 views

Get tab key to indent a block of code

Is there some way I can change Mathematica keyboard behavior so I could select a block of text/code, press tab, and the selection would be indented to right? Similarly, I would like shift+tab to ...
10
votes
2answers
1k views

How to write data from Mathematica to an existing formated Excel file?

I have a sheet in an Excel file already formated: different colors, fonts, columns width and cells styles. I want to fill-out values from Mathematica into specific cells of that sheets, or use that ...
10
votes
0answers
158 views

Is there a convenient/automatic way of uploading a notebook into SE?

This post discusses how to streamline the other way - extracting code from a fragmented and longish SE answer but I imagine a two-way workflow like: Fashion an answer/question in an SE-templated ...
10
votes
3answers
2k views

How to make a tight crop of a 3d plot?

I like Mathematica, but it's syntax baffles me. I am trying to figure out how to minimize the whitespace around a graphic. For example, ...
10
votes
4answers
434 views

Building a tree

Given a list of word characters, such as this one, I'd like to build a tree, similar to this makeTree function, but with the tree in a different format. So, for an input such as ...
9
votes
3answers
272 views

How to plot a series using different colors depending on the y-value

I have a sequence of numbers ${x_1,x_2,\ldots,x_n}$. I would like to plot the sequence using ListLinePlot but use a different color depending on if the values $x_i$ are within $a_i<x_i<b_i$. ...
9
votes
1answer
169 views

Show graphics content in front of frame

Consider some graphics which spill over the plot range, like these: ...
9
votes
1answer
74 views

Using PatternSequence on its own in ReplaceAll?

Say I have this list: list = {0, 1, 2, 0, 1, 3, 0, 1, 4} and say I want to remove consecutive sequences of 0 and 1. I'd normally go for this: ...
9
votes
2answers
1k views

What is the best distribution for my histogram?

I defined a security bound for a random walk (cube with 15 lengh) and i have this code to obtain a sample of the random times at which the random walk crosses the boundary for the first time: ...
9
votes
1answer
158 views

How to avoid CopyTensor in CompiledFunctions?

In a reply here Leonid wrote, “Compile can handle a number of higher-level functions, such as Transpose, Partition, Map, MapThread, etc. Most of these functions return expressions, and even though ...
9
votes
1answer
619 views

Workflow in the Mathematica and Workbench IDE

After visiting one of the Wolfram presentations, I started writing code for my number theory research project in Mathematica because I found it to be faster than Sage. I downloaded Workbench and ...
9
votes
2answers
611 views

How can I create a fountain effect?

Inspired by this (please use Chrome or Firefox), I tried to simulate it, but I couldn't do it. I'm not familiar with Dynamic. Here is my simple code: ...
8
votes
1answer
177 views

Vertex merging in graph?

Given a Graph such as the one produced with the following code ...
8
votes
1answer
135 views

CSS Selectors for Symbolic XML

Symbolic XML is a convenient way of managing XML in Mathematica, at least for casual use or small tasks. Here and elsewhere you can find examples of XML handling in Mathematica, including XSLT/XPath ...
8
votes
1answer
559 views

How to combine more locations (GPS coordinates inside one city) with Google map?

I have a list of GPS coordinates.E.g. GPSList = {{47.680800, 17.626446}, {47.681078, 17.627283}, {47.682759, 17.631810}}; I would like to crate a Google Map ...
8
votes
3answers
475 views

1D quasicrystal: points on a line nearest to points on a lattice

I have a simple lattice / line manipulation: ...
8
votes
2answers
692 views

Can you apply the Cellular Automata function to a grid containing numbers?

Im attempting to simulate a simple evacuation model using cellular automata theory.My study aims to determine whether Cellular Automata can effectively represent how people would behave in a fire ...

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