# All Questions

2k views

### Make a density list plot/histogram from large, pre-binned data set?

I have a large data set consisting of $\mathcal{O}(10^9)$ two-dimensional points. In order to save memory and time I have pre-binned these into a uniform grid of $500 \times 500$ bins using Fortran. ...
510 views

### Assessing argument type in set delayed function definitions

I'm wondering how to properly assess the type of arguments passed to functions defined with :=. I want my functions to be the most efficient, unambiguous and clear ...
574 views

### What's the most “functional” way to do Cholesky decomposition?

I can do Cholesky in a procedural style, such as: ...
260 views

### Old values are not freed/garbage collected when you re-evaluate an assignment

For this code: (* Cell 1 *) generate := Module[{x}, x = Range[100 * 1000 * 1000]; x]; (* Cell 2 *) g = generate[]; MemoryInUse[] If I evaluate cell 2 ...
2k views

### Combination and Permutation

How could I obtain the list of all the groups of 5 numbers taken from Range[12] such that the 2 lists have an empty intersection : ...
68 views

### Unexpected pattern matching behaviour: PatternSequence vs. Optional

Consider the following pattern-matching expressions: ...
224 views

### Is there a way to control V10's undo length?

This may be a duplicate (if so I will remove this), but I was having trouble finding the relevant bit of documentation to fix it. I noticed that my FrontEnd memory ...
499 views

### Are there tools for getting Mathematica 9 Notebooks working in Mathematica 10?

As often happens with Mathematica updates, nearly all of my notebooks no longer work as they did with the previous version. The upgrade from 9 to 10 has changed the appearance or introduced errors ...
197 views

### Why is my rasterized graphic blank?

Consider the following code: ...
408 views

### How can I access the internal function that plots a molecule from a formatted XYZ file?

Mathematica has the ability to plot a molecule using the data contained in an XYZ file. This is a simple text file, of which this is an example. The molecule is plotted using the Import command. ...
649 views

### How can I Flatten this List with Inner List of Lists?

Given the following List ...
164 views

### Are formal characters like \[FormalA] to be used differently than other symbols?

I noticed that Mathematica has a set of special 'Formal' characters such as \[FormalA], \[FormalB] , etc.. In the front end, it ...
605 views

### How to send output of Information[] command to a text file?

I am having little hard time sending output of Information[] command to a text file. related question How to write output to an external text file in addition to ...
449 views

### How to use pattern matching to assign values to Subscript[f,x_]?

I want to define two subscripted functions Subscript[f,1] and Subscript[f,2]. To keep the assignments local, I would like to ...
794 views

Is it possible to avoid this unreadable situation with label crowding when using PieChart's RadialCallout and ...
684 views

### Count consecutive positions with the same value

I want to program a function that counts the successive positions with the same value: In[]= ConsecutiveValues[{1, 1, 1, 1, 2, 2, 1, 0}] Out[]= {4, 2, 1, 1} In ...
248 views

### Encoding format used by GraphicsData?

I am trying to extract some graphics stored in PICT format from a Mathematica notebook, using a platform that doesn't support PICT. If I look at the .nb file in a ...
453 views

### Mathematica Source-Code Control for CDF files in multi-user scenario

Q: I'm putting together a strategy on how its best to maintain cdf documents with multiple users in a source code repository. Ideally I wish for users to create (unit tested) cdf's with data and ...
5k views

### subscripts in plot axis labels

Superscripts can be included in axis labels by the use of the caret symbol (e.g., Plot[x^2, {x, -1, 1}, AxesLabel -> {x, x^2}]). How does one include subscripts ...
848 views

### Passing down arguments

In R, one can use ... to pass arguments down to another function. For example ...
1k views

### Most Efficient Way to Calculate the Product of All Items in a List?

Say that I have a list of returns on a financial asset over time and want to know the total compounded return. To get the answer, I need to add 1 to each return and then calculate the product of all ...
544 views

### How do you efficiently return all of a List but one element?

I have a problem that I am working on that requires that I compare several lists of overlapping data points. As I traverse one of the lists, I'd like to only compare those data to the other lists, and ...
87 views

I tried to install LinkSnooper on my Windows 7 computer, as described in the documentation and here. According to the answer of @Todd Gayley, I entered the following string in the field MLOpen: ...
817 views

### Solve Laplace equation using NDSolve

I am new to Mathematica, a friend recommended this software and started using it, in fact download the trial version to know. I recently did a program in C to calculate numerically the solution to ...
347 views

### Converting structured data to a dataset

A Dataset seems perfect to represent structured data. Has anyone already thought about how to convert as efficiently/elegantly as possible an XML or JSON file to a Dataset in Mathematica 10 ?
2k views

### Why is this semicolon in red?

I have a piece of code that works well, but when I put a semicolon after a plotting statement, the semicolon appears in red. What's the error?
524 views

### Memory leak issues

I am working with noncommuting objects and basically I am using Mathematica to sort large expressions by normal ordering and simplifying them. To this end, I first create an object called ...
13k views

After macosx 10.9 mavericks upgrade i have a compilation problem, you can see below. Even the examples given in ...
410 views

### When should I use Apply (or Function) and when @@ (or &)?

This is a rather general question, which I fail to answer myself. I guess it is mainly due to my insufficient knowledge of the precise terms. If I understand correctly, the following are equivalent: ...
266 views

### Efficiently filling area with disks located at certain points

Starting from a set of points, I want to fill an area using disks. Each disk's center should be one of the points and the disks should not overlap. I've managed to write a function that, given a list ...
304 views

### Is there a way to programmatically set global preferences?

Can I set global preferences that are accessible via "Edit"->"Preferences" programmatically from within a notebook? As learned from this question, turning off anti-aliasing can make a huge difference ...
540 views

### Extracting vertex coordinates from an automatically laid out graph

Given a Graph with an automatically computed layout (i.e. not explicitly given VertexCoordinates, but using a ...
321 views

### Transition between graphs

I want to visually demonstrate the manipulations made to a graph. For instance, I have a graph g where using the command ...
379 views

### Why is AstronomicalData so slow?

I'm having trouble getting some pretty simple functions using AstronomicalData to perform at anywhere near the speed I need them to. For example, I have many ...
236 views

### Strange results while nesting scope constructs?

I did a handful of tests with Block, With, and Module and had a couple of new surprises. ...
518 views

### Different calculation of median and quartiles, bug in BoxWhiskerChart?

When you plot a dataset with BoxWhiskerChart passing over the box in the plot with your mouse pointer shows some specifics about the dataset (min and max values, ...
649 views

### Improve speed for calculating a recursive sequence

I want to calculate following recursive sequence: $\alpha_{0}=0,\\ \cos(\alpha_{i})=\cos(\alpha_{i-1})\cdot\cos(\beta_{i})+\sin(\alpha_{i-1})\cdot\sin(\beta_{i})\cdot\cos(\gamma_{i}).$ In ...
407 views

### How to use Locators on a graphic in a tabview

Background: I want to split graphics in a Manipulate in several parts in a tabview control. But the tabview somehow interferes with the locators as in the following simplified example: ...
293 views

### How can I add row and column header images to my TableForm output?

I am experimenting with the Eigenfaces algorithm and have my notes and experimental data collected in a Mathematica notebook. The result of an experimental run is a table of scores, where the smallest ...
171 views

### Is there a way to have a Tooltip for non-editable raster graphics produced by MakeBoxes?

I have a function which produces a large object I would like to hide. Formatting is of course an option but I'm hoping for something a little more meaningful using raster graphics and ...
275 views

### SubTitle and SubSubTitle do not group by default

For some reason, the SubTitle and SubSubTitle cell formats do not group automatically on my machine any more, and I cannot ...
388 views

### What is my problem with MeshFunction?

I want plot the max value in a sine plot. We can use the following code ...
200 views

### Inconsistent DistributionFitTest results?

In pondering this question, I used Mariana's function to generate the following data. ...
201 views

### The introduction for Context in Wagner's book is out of date? [duplicate]

In Section 8.1.1 (P230 of the book, P249 of the PDF) of Wagner's book, the following example is shown: x = 5; tempx = 6; Begin["temp"]; {x, Global`x} The ...
313 views

### Deleting quasi-duplicates from large list efficiently

I have the need to remove "duplicates" from large (>10K members) lists, where a "duplicate" is either a verbatim duplication, or the element's second entry exists as a first entry for some "earlier" ...
344 views

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307 views

### How to convert Graphics3D object into an Image3D object?

How does one convert a Graphics3D object into an Image3D object? E.g., start with ...
305 views

### How can I define a Listable function only apply to a vector?

Consider the function f which should behave as f[{{1, 2}, {3, 4}, {5, 6, 7}}] ...