Questions on undocumented functionality of Mathematica. Note that such functions might be subject to change without notice in future versions.

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14
votes
0answers
141 views

Undocumented fourth parameter of Collect; how long has it been there?

While tinkering with How to get a list of monomials of a polynomial without coefficients? on a whim I tried a fourth argument in Collect and found: ...
11
votes
2answers
191 views

What will happen if I set ExclusionsStyle for points in 2D plot?

For example f[x_] := (x^5 - 4 x^2 + 1)/(x - 1/2); Plot[f[x], {x, -1, 2}, Exclusions -> {f[x] == 0}, ExclusionsStyle -> Dashed] Has the ...
13
votes
1answer
134 views

How to retrieve current FaceForm?

The current colour in a Graphics object can be retrieved using CurrentValue["Color"] for use in Dynamic stuff. Example: ...
5
votes
1answer
60 views

Can Someone Please Explain Internal`$SameQTolerance?

If I input Internal`$SameQTolerance (* output = 0.30103 *) which is the approximation of Log[10,2], or ...
12
votes
1answer
160 views

Is there a way to control which special forms Normal converts?

Normal documentation reads: Normal[expr] converts expr to a normal expression, from a variety of special forms. But is there a way to control which special ...
10
votes
1answer
227 views

How can I make FilledCurve smoother?

In How can I generate and randomly assign color to annular sectors? J.M. showed an interesting way to create a sector graphic using FilledCurve. Unfortunately it ...
8
votes
1answer
124 views

What's the goal of the Macros` package?

I see in the Mathematica install a Macros` package. In windows the paths is for example: ...
8
votes
1answer
171 views

Possible Method for MatrixExp

Well, probably a hard question, but I think it's better to cry out loud :). I noticed that MatrixExp owns Method option when ...
18
votes
1answer
379 views

What are SparseArray Properties? How and when should they be used?

A strange undocumented form of SparseArray is increasingly used in answers on this site: ...
16
votes
1answer
264 views

In 10.1.0 BenchmarkPlot doesn't work?

In Mathematica 10.1.0 BenchmarkPlot from the GeneralUtilities package doesn't work; copying Taliesin Beynon's initial use of the function on this site: ...
1
vote
0answers
31 views

Understanding HoldSequence and ReleaseHoldSequence in Error Handling

I was playing with GeneralUtilities`PrintDefinitions in V10.1, and find some of native Mathematica functions using ...
24
votes
0answers
332 views

Documentation of the frequently-used functions in the context of Internal` and Compile` [duplicate]

In this site, I have gradually found out that there is a collection of functions in all kinds of answers. For instance, Compile`GetElement, ...
10
votes
1answer
160 views

Enigmatic message about MaxBend

Referring to the method I proposed for Problem with ParametricPlot Mathematica 10.0.2 throws an enigmatic error message: ...
10
votes
2answers
181 views

Why is a symbol still found after changing its context?

It seems that we can change the context of symbols: In[1]:= x = 1 Out[1]= 1 In[2]:= Context[x] = "foo`"; But then x is still ...
3
votes
0answers
47 views

Undocumented options for “BalloonEmbedding” in GraphLayout

From an error message, I see some options of the BalloonEmbedding method for GraphLayout: ...
4
votes
1answer
82 views

What are all the Properties that ColorData supports?

The documentation for ColorData reads: Possible properties in ColorData["scheme","property"] include: ...
8
votes
2answers
265 views

What does IndexBy do and how exactly does it work?

I just saw the function IndexBy in the autocomplete suggestions and I was curious to know exactly how it works. Unfortunately, there's no trace of it in the ...
17
votes
1answer
181 views

Reading from a socket stream

I noticed an undocumented socket package (SocketLink) in Mathematica (Using version 10, not sure when it was actually added) and wrote a barebones HTTP responder ...
4
votes
2answers
163 views

Is there a build-in function converting a quantity to one with mixed units (such as feet and inches)?

For example, I want to convert 179 centimeters into 5 feet and 10.4724 inches instead of 70.4724 inches (as this website did). Maybe in the future I would need to convert days to {years, months, days} ...
15
votes
2answers
308 views

What is the purpose of Internal`LocalizedBlock?

I have come across the (internal) use of of the function: Internal`LocalizedBlock I am trying to determine its purpose. It seem to behave like ...
2
votes
1answer
54 views

When is are these additional docked cell styles used?

The the style "DockedCell" is automatically used for Docked Cells even when no Cell style is specified. In the section of ...
3
votes
0answers
61 views

Lists for built-in functions that can work without brackets

I just noticed that Exit and Quit can work without brackets i.e. a single Exit or ...
6
votes
1answer
134 views

What are the arguments supplied to ColorFunction in MandelbrotSetPlot?

On the document of MandelbrotSetPlot, it said: With ColorFunction->f, where f is a function, the argument of f is a real number in proportional to the number of ...
5
votes
2answers
153 views

Finding out all undocumented values for “Properties” in XxxData[] functions

No, XxxData[] is not a new function in Mathematica 11. I am just using that name for all curated data-related functions. As you know, ...
1
vote
1answer
70 views

In which version was this Extract syntax introduced?

In Mathematica 10.0.1 this works: Extract[{a, b, c, d, e}, {{{1, 3}}, {{5, 4}}, {{2}}}] {{a, c}, {e, d}, {b}} In ...
5
votes
1answer
105 views

RawArray crashes the kernel

fixed in 10.0.2 RawArray seems to crash the kernel on my machine RawArray["Byte", {}] Is this a bug? Any insights why this happens? My system: version 10.01 ...
12
votes
2answers
177 views

Listable functions thread over Associations; is this documented?

Thanks to a somewhat misapplied use of MapThread I learned of this behavior: ...
2
votes
1answer
81 views

How to obtain a complete list of WordData's “Properties”?

Command WordData["Word", "Properties"] seems to return an endless list of properties, such as: "Definitions", ...
4
votes
1answer
141 views

Undocumented overload for Graph?

I stumbled (here, in the expression for the block diagram) upon a version of Graph that I don't see in the documentation over here. That documentation admits three overloads (the following are in my ...
5
votes
0answers
57 views

Is “MaxMessageCount” broken or is its function counter-intuitive?

Behavior remains unchanged through Mathematica version 10.1.0 As noted by kguler the Front End option: MessageOptions -> "MaxMessageCount" does not appear to ...
22
votes
2answers
569 views

Specifying non-conflicting PlotTheme options

A bug or limitation in 10.0.0 affects a few of these examples; it was resolved in 10.1.0. I am trying out Mathematica 10 on https://programming.wolframcloud.com. ...
8
votes
0answers
194 views

TableView displays negative numbers incorrectly

I'm trying to substitute TableForm with TableView because TableView is more handy with big data . But on my Mathematica 9.0.1 (ubuntu 14.04_64bit) there is a problem with negative numbers: ...
24
votes
1answer
819 views

Undocumented use of Integrate: Integrating over regions

I have come across a few questions asking about integrating over regions. And while the answers are impressive there should be a better more consistent way. So my question is, are there ways, ...
5
votes
1answer
124 views

Undocumented WolframLibraryData::evaluateExpression

It seem there's this promising function in the callback object provided to MathLink C functions: ...
25
votes
1answer
616 views

Undocumented form for Extract

Prompted by a comments conversation here, here's an interesting (and often performance enhancing) use of Extract: ...
5
votes
0answers
105 views

SparseArray internal structure [duplicate]

According to the documentation: SparseArray is treated as a raw object by functions like AtomQ and for purposes of pattern ...
7
votes
1answer
334 views

How to use Undocumented Functions Prism, Tetrahedron and Hexahedron

Taking a look at this question and this one, I checked to see if Mathematica really does not have a Prism primitive. To my surprise the function ...
18
votes
1answer
525 views

What does ImageSize -> 1 -> 1 mean?

On the page http://www.wolfram.com/language/gallery/blur-faces-in-an-image/ the example code has ImageSize -> 1 -> 1. I am unfamiliar with this chaining of ...
22
votes
1answer
491 views

How to work with Experimental`NumericalFunction?

This question is intimately connected with previous one: "How to create internally optimized expression for computing with high WorkingPrecision?" Oleksandr R. correctly states in the comment: A ...
15
votes
0answers
193 views

Graphics`Mesh`FindIntersections[ ] fails to detect intersections

Graphics`Mesh`FindIntersections[ ] is an undocumented function for, well, detecting intersections very efficiently. Take a look: ...
12
votes
2answers
340 views

Behavior of Reduce with variables as domain

When using Reduce, I accidentally put a set of variables as the domain. To my surprise, it not only seems that Reduce expects ...
15
votes
1answer
229 views

The second argument of Signature

I've noticed that Signature can have an undocumented second argument. What does it do? Signature[{1,2,3,4}, ?]
31
votes
4answers
627 views

Any ideas on how to use the Region` context?

If you type ?Region`* you'll get: which seems a bunch of interesting and not documented symbols. Any idea (or experience) on how to use them? Edit By ...
6
votes
0answers
192 views

Documentation for user-defined functions; undocumented documentation feature?

I stumbled on some strange behaviour when trying out the new function template and documentation features, now purportedly working in v 9.0.1. I defined a function ...
4
votes
0answers
62 views

“ClosingActions” option for FrontEnd`AttachCell

I'm looking to find the possible values for the ClosingActions options FrontEndAttachCell. I have found ...
8
votes
1answer
128 views

Strange behaviour of Internal`InheritedBlock

I was going to post an answer for fast way to replace all zeros in the matrix. I was even quite happy because timings were the same order of magnitude as others. The idea was to overwrite ...
5
votes
1answer
87 views

Syntax for FrontEnd`SelectionSetStyle

I know FrontEnd`SelectionSetStyle is undocumented, but its name suggests it does what I need. What is its syntax? I have already tried several variations of the ...
21
votes
2answers
543 views

How to write beveled fractions?

How to write beveled fractions like ${}^a/_b$? In contrast to $\frac{a}{b}$ and $a/b$ (see this question).
7
votes
0answers
163 views

Finding hidden treasure (aka finding undocumented functions) [duplicate]

I was searching for a way to determine if a point is within a polygon and stumbled upon rm -rf's answer. (actually, I really wanted to find a point within a ...
4
votes
2answers
151 views

Workaround for Import not supporting the \leqslant TeX macro

$\{A\leqslant x\leqslant B\}$ Copy the code into Notebook, and you'll lose the less sign, this can be rendered well in ...