# All Questions

320 views

### Using map projections with astronomical data

I noticed that all important "Geoprojections" are available in projections for a spherical reference models: GeoProjectionData function; 1 - I am trying using the sinusoidal projection for ...
315 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 ...
296 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, ...
449 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 ...
305 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. ...
287 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 ...
602 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 ...
847 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 ...
159 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 ...
261 views

### ShearingTransform and Dynamic

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

### How to change default notebook background color?

How does one change the default notebook background color?
431 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 ...
487 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. ...
378 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) ...
354 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 ...
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 ...
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, ...
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 ...
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 $a_i<x_i<b_i$. ...
171 views

### Show graphics content in front of frame

Consider some graphics which spill over the plot range, like these: ...
75 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: ...
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: ...
160 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 ...
640 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 ...
613 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: ...
179 views

### Vertex merging in graph?

Given a Graph such as the one produced with the following code ...
138 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 ...
596 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 ...
291 views

### Add lines to 3D Plot

How can I add lines that demarcate the different regions of the following 3D plot: Plot3D[1/(1 + E^(-a - c)), {a, -8, 8}, {c, -8, 8}] To give you an idea of what ...
555 views

### High Contrast Syntax-Highlighting

I have a neurological disorder which causes me to have migraines if I look at a white computer screen. To combat this, I have put the following at the top of all of my Mathematica notebooks: ...
212 views

### Palette button with progress bar

Let's say you have a palette with a button that has to do some time-consuming task when clicked: ...
325 views

### How to prevent instability blow up in NDSolve?

I have the following code to solve a PDE: ...
271 views

### How to generate nonperiodic tilings?

I need to generate nonperiodic tilings which are similar to the attached figure (kite-domino tiling). I was thinking the code is similar to the code for the Penrose tiling. However, that code is too ...
2k views

### How to find the Shortest Path, visiting ALL vertices, without coming back to the start (Hamiltonian Path, minimum distance)

A car has to pick up each person and take them to their destination. I am trying to find the shortest tour that will do this. How can I find the shortest path between any s and t.... visiting all ...
5k views

### Does Mathematica implement the fast Fourier transform?

Is there a fast Fourier transform in Mathematica? Although looking in the help I could not find one. I am looking to implement the equivalent of fft in MATLAB.
313 views

### Connect neighbouring points as list of segments in 2 D

Context I am interested in connecting neighboring points in 2/3D as list of segments. I am guessing this is something within the reach of graph theory, which is well implemented in mathematica. ...
464 views

### Building a molecule viewer: aesthetic rotations

I am working on building a molecule viewer in Mathematica and am running in to problems with controlling rotation of the molecule (which is rendered as a ...
613 views

### Export to CSV is very slow - can performance be improved?

I have to provide data exports from Mathematica to CSV format and it is very slow compared to other formats as can be seen in the following table: JSON, 15 sec, 8.4 MB TXT, 23 sec, 5.6 MB XLSX, ...
7k views

### Quick Hessian matrix and gradient calculation?

I am absolutely new to Mathematica and I actually want to try implementing a little optimization method . Long story short assuming I have a predefined two-variable function f(x,y) I want to ...
115 views

### Are there any videos that show how different Mathematica expressions are evaluated?

Are there any videos that show how different Mathematica expressions are represented internally as object graphs and demonstrate how they are transformed during an evaluation? I am asking because I ...
405 views

### What is the status of ::usage and Templates in Mathematica v10.1?

In Mathematica 9, a number of issues concerning the ::usage and templates were raised. In 9.0, there was a bug first reported here and better diagnosed here, where ...
589 views

### Compiling ColorFunction for faster complex phase-amplitude plots

I have gotten into the habit of plotting complex-valued functions on a plane using a color-function along the lines of ...
822 views

### Are there any “RLink” like projects, which enable the interaction between R and Mathematica?

I want to borrow the vast amount of packages of R. I know there was one but it is neither sold nor supported anymore. So are there any active open source projects for linking R with Mathematica? Thank ...
3k views

Since PolarPlot doesn't support Filling, what is the best way to shade or fill the a region between two polar curves? For ...
2k views

### Unsaved notebook is crashing: is there any way I can save the state of the MathKernel before I kill it?

So I'm in the middle of generating some plots and all of the sudden the frontend goes dead and I haven't saved my work. I'm using Mathematica 8 in MacOS X. The MathKernel process is still running and ...
720 views

### When to make (file.nb) instead of (file.cdf)?

I started with File > New > FreeCDF so I can save my work in a format compatible with the CDF Player. I can use Mathematica to make new cells, evaluate input and so in the CDF file. What are the ...
988 views

### Graph vs GraphPlot

What is the difference (in purpose) between Graph and GraphPlot? Which function is bested suited to which tasks? Background: I ...
622 views

### Using Transpose with a list as the second argument

I'm having difficulty understanding the Transpose function. I know what the transpose of a matrix is, not a problem, and I see that applying the ...