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

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6
votes
2answers
143 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 ...
11
votes
0answers
103 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 ...
3
votes
2answers
122 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
274 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
45 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
58 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 ...
5
votes
1answer
110 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 ...
3
votes
2answers
109 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
63 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
91 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 ...
11
votes
2answers
159 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
46 views

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

Command WordData["Word", "Properties"] seems have an endless list of properties, such as : "Definitions", ...
4
votes
1answer
135 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
48 views

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

As noted by kguler the Front End option: MessageOptions -> "MaxMessageCount" does not appear to have any affect on the number of times a Message is repeated ...
7
votes
0answers
162 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: ...
22
votes
1answer
557 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
113 views

Undocumented WolframLibraryData::evaluateExpression

It seem there's this promising function in the callback object provided to MathLink C functions: ...
23
votes
3answers
555 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
102 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 ...
8
votes
1answer
293 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
517 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 ...
21
votes
1answer
423 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 ...
11
votes
0answers
150 views

Graphics`Mesh`FindIntersections[ ] fails to detect intersections

Graphics`Mesh`FindIntersections[ ] is an undocumented function for, well, detecting intersections very efficiently. Take a look: ...
7
votes
2answers
216 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
223 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
576 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
169 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
50 views

“ClosingActions” option for FrontEnd`AttachCell

I'm looking to find the possible values for the ClosingActions options FrontEndAttachCell. I have found ...
7
votes
1answer
120 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 ...
2
votes
0answers
39 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
482 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).
6
votes
0answers
155 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
142 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 ...
41
votes
1answer
1k views

How can I manipulate TemporalData?

Version 9 introduced TemporalData but, truth be told, the documentation doesn't suggest that one can do much with it. Many of us have probably assumed we'd be ...
17
votes
2answers
399 views

What are all the named Mathematica styles?

This question came to mind because of this answer to a recent question. Under Style, the Mathematica Documentation Center says the following about named styles. A few common named styles ...
4
votes
0answers
213 views

Strange behavior of undocumented RawArray and ArrayObject expressions

I discovered several strange results and inconsistencies while trying to understand what undocumented RawArray and ArrayObject ...
10
votes
1answer
213 views

Is there a method to enumerate the keys/values of System`Utilities`HashTable

Lacking from the simple API of System`Utilities`HashTable is a method to enumerate the keys/values. ...
25
votes
1answer
255 views

What does Internal`InheritedBlock do?

What does the function Internal`InheritedBlock do? How is it different from the regular Block?
1
vote
0answers
88 views

Does Graphics`Mesh`SimplePolygonQ[] work for you?

Graphics`Mesh`SimplePolygonQ is an undocumented function. I'm using Mathematica 7, and when I try: ...
4
votes
1answer
559 views

What's the simplest way to plot an ErrorListPlot with only y error bars?

Sometimes I get really tired of Preparing data for making an ErrorListPlot using Thread and friends. Is there a simpler way to plot an ErrorListPlot with only y ...
5
votes
3answers
710 views

Parameters for the CIE XYZ Color Space in Mathematica

In Mathematica, producing a color based on its RGB parameters is easy; one can use (for example) ...
4
votes
1answer
352 views

A Graphics`Mesh`ConvexHull[] peculiarity

I have been unable to explain the behavior of Graphics`Mesh`ConvexHull[] on the following (highly simplified) example: ...
9
votes
2answers
354 views

Is there a “GrabHand” and “OpenHand” MouseAppearance in Mathematica?

MouseAppearance[Plot[Sin[x], {x, 0, 5}], "LinkHand"] Unfortunately I cannot get a screen grab to show the link hand but it is a cartoon hand with a finger ...
4
votes
2answers
270 views

How to get a list of available appearance/styles?

This is a basic question but I haven't found any answer yet :/ Available appearances for Button[] are mentioned in Help, those ...
7
votes
0answers
158 views

How can we extend the predictive interface so it can suggest new operations?

Introduction Mathematica 9 has introduced a new predictive interface. For each output, it suggest possible actions the user might want to take. How can this interface be extended so that it will ...
7
votes
1answer
289 views

What are \[InvisiblePrefixScriptBase] and \[InvisiblePostfixScriptBase]?

In the non-printing characters documentation, I see two named characters that are largely undocumented: \[InvisiblePrefixScriptBase] and ...
3
votes
1answer
113 views

Specifying a graphics object for the width of a median marker

In a previously posted question VLC used the element specification {"MedianMarker", filledCircle[10], Black} in a box and whisker chart, where ...
8
votes
1answer
271 views

What is the complete list of valid FrontEnd Packet types?

In response to my question How can I get the unchanged Box form of an arbitrary expression? John Fultz answered with a method using the hilariously named ...
19
votes
1answer
296 views

What does “EquationalLogic`FindCounterexample[]” do?

I found the undocumented EquationalLogic`FindCounterexample[] by browsing the lists of available symbols, but I have no clue about its purpose. The name is ...
7
votes
0answers
186 views

What Method options does FindInstance accept?

While answering Trouble getting FindInstance to return multiple results for certain constraints it became clear that for this problem FindInstance would be better ...