Questions tagged [undocumented]
Questions on undocumented functionality of Mathematica. Note that such functions might be subject to change without notice in future versions.
256
questions
13
votes
1answer
163 views
What does Reduce`FreeVariables really do? And can we rely on it?
Very frequently, in answers on this site, the undocumented function Reduce`FreeVariables comes up in the context of generating a list of variables inside an ...
0
votes
0answers
60 views
How to make my custom neural layer only apply noise during training (similar to how DropoutLayer behaves)?
Utilizing some undocumented Mathematica functionality, I implemented it like this:
...
5
votes
1answer
119 views
How to author a workflow?
I find the workflow refpages in the doc center very helpful, and I'd like to make some of my own:
Workflows seem to be notebooks of "Text" and ...
4
votes
1answer
79 views
Is it possible to get current thickness for every Line, Polygon, Circle object in a plot?
When exporting Mathematica graphics to raster formats with high resolution the common problem is that thickness for such objects as Line, ...
14
votes
1answer
118 views
Why does setting SyntaxInformation add a definition to DefaultValues
Before setting any definitions to the symbol f, the DefaultValues of f is empty:
...
5
votes
1answer
41 views
How to extend the DefaultDuration of Manipulate[] when it has Bookmarks?
How to extend the DefaultDuration of
Manipulate[x,{x,0,1},Bookmarks->{"beginning":>(x=0),"end":>(x=1)}]
to 20 ...
6
votes
1answer
96 views
Is it possible to make listable Experimental`NumericalFunction?
I have been playing a bit with the undocumented function
Experimental`CreateNumericalFunction
and I wanted to know if somebody found a way to make generated ...
5
votes
0answers
112 views
Status of Streaming package
I see the Streaming package mentioned in this question
How to use Streaming package in v11.1?
with advice on getting it working in V11.1.
I've failed to get either the built-in version or the patch ...
1
vote
1answer
95 views
Problem with “MediaTools`” in Mathematica 12
I asked here for a solution how single video images can be extracted very fast from avi files.
Piotr Wendykier gave a solution for Mathematica 11.3.
Now I'm using Mathematica 12 and his solution ...
2
votes
1answer
51 views
TemporalDiscretization in MethodOfLines
When solving ODE's one can use options like MaxStepFraction to control the number of grid points.
When solving PDE's ...
1
vote
0answers
57 views
Understanding how ComponentMeasurements finds neighbors
I am trying to understand how the module ComponentMeasurements in Mathematica works when the property Neighbors is called in ...
6
votes
1answer
71 views
How to vectorize this nonlinear ODE system for NDSolve?
I learned a long time ago that NDSolve can often be sped up by vectorizing systems of equations. I've got a problem now that seems ideal for this approach, but I ...
3
votes
1answer
101 views
Implementing the Peano-Baker Series with Mathematica
I would like to calculate the Peano-Baker series with mathematica, namely an integral expansion to approximate the state transition matrix:
Say I have a matrix $A(t)$ and I want to calculate:
$\Phi(...
8
votes
1answer
101 views
Can we construct our own NDSolve`StateData?
NDSolve can be broken into three stages:
NDSolve`ProcessEquations processes the equations and sets up an NDSolve`StateData ...
13
votes
1answer
151 views
Can't make more than 249 Internal`Bags in a Table
I need a lot of Internal`Bags so I made them with Table. It works fine for 249 or fewer Bags...
9
votes
0answers
106 views
How to modify NDSolve`StateData without crashing the kernel?
Probably a hard question, but it's better to cry out loud.
Reminded by Chris K, I noticed my fix function has been broken since v11.3. After some checking, I ...
5
votes
1answer
62 views
MatrixConditionNumber does not work in version 12.0
A = {{1., 0.}, {0., 2.}};
LinearAlgebra`MatrixConditionNumber[A]
3
votes
1answer
214 views
What is the most reliable way to find a particular function?
I learned there're built-in functions which is not documented from this question.
After this , I tried looking for something which is usable for me,then noticed that with ...
5
votes
0answers
93 views
Reverse Engineering of MMA `Classify[]` Output?
Update: as @AntonAntoniv rightly noticed in his comment the case of DecisionTree is already discussed. Now it would be great to also have an equivalent answer for LogisticRegression.
MMA is really ...
7
votes
1answer
45 views
Can I reimplement something like TogglerBox?
As a purely academic exercise can I make a box structure that'll toggle between two views when clicked and that doesn't ever depend on Dynamic or ...
5
votes
1answer
71 views
How to not show line mesh elements
Let's say I make a mesh from a collection of random points:
SeedRandom[1234]
points = RandomReal[1, {20, 2}];
mesh = VoronoiMesh[points]
For the purposes of my ...
0
votes
0answers
67 views
Evaluating Internal`$VideoEncodings gives a strange message
When calling Internal`$VideoEncodings to check available video codecs on my pc, Mathematica_11.3 gives a message:
...
2
votes
0answers
43 views
Why does the kernel strip \< and \> from strings [duplicate]
The FE always passes strings to the kernel that look like:
"\"\<asdasd\>\""
And the \< and > get pruned out. We can simulate this for ourselves with:
<...
5
votes
1answer
117 views
How can I see all FE nine-patch bitmaps?
The FE stores a bunch of little nine-patch images in the layout that govern the appearance of much of Mathematica. These things are incredibly useful to have as they may be used to give a clean ...
0
votes
0answers
42 views
Second argument Run[]
Run officially takes only one argument. I encountered code with Run[command, "Text"], is this a mistake or is the second argument meaningful? If so what does it do? ...
0
votes
0answers
31 views
Method option of function MatrixRank
By running ??MatrixRank, I see that it has an optional argument named Method.
However, this argument is not in the ...
5
votes
1answer
79 views
Making an Association-like interface for HashTable
System`Utilities`HashTable is conceptually a lot like an Association but it has the pretty phenomenal (for Mathematica) property ...
7
votes
1answer
64 views
Custom Property interface on my own objects
I know I can use the Property interface for things like Graph but I want to use it for all of my objects. This includes:
...
3
votes
1answer
67 views
Custom conversion rules in UnitConvert
I want to make UnitConvert operate on custom units with special rules.
For instance, I would like to be able to convert between ...
2
votes
0answers
33 views
Create a ProcessObject for a process not made with StartProcess
I am launching and linking to Mathematica from an external process and would like to be able to create a ProcessObject for the launching process that will support <...
3
votes
0answers
43 views
How to make custom attached menubars? [duplicate]
I would like to understand how to build an attached menubar. For example, Image has the following bar - an attached cell that arises when clicked on:
...
4
votes
1answer
167 views
Others problems with Graphics`PolygonUtils`PolygonCombine
As a continuation of this question, writing:
...
8
votes
2answers
231 views
Problem with Graphics`PolygonUtils`PolygonCombine
Writing:
Normal@ParametricPlot[{x, x^2 t}, {x, 0, 2}, {t, 0, 1}] /.
p : {__Polygon} :> Graphics`PolygonUtils`PolygonCombine[p]
I get:
but if I write:
...
6
votes
1answer
122 views
Undocumented GraphComputation`GraphProduct usage
According to Mathworld there is an undocumented function
GraphComputation`GraphProduct[G1, G2, "Cartesian"]
To compute the cartesian graph product.
Now in ...
4
votes
0answers
32 views
Get all built-in image files for styling buttons and panels
Mathematica makes use of nine-patch images in styling its resizable interfaces like Panel and Button. Nicer than remaking new ...
15
votes
1answer
287 views
What happened to SequenceLimit?
In older versions of Mathematica, there was a function called SequenceLimit that allowed taking the limit of a numerical sequence. It is useful for speeding up the ...
3
votes
0answers
86 views
Language`ExpressionStore and ParallelMap
Is there a way to access NewExpressionStore from within a parallelized calculation? I have tried variations of
...
7
votes
0answers
61 views
Special forms for autocompletion strings
Szabolcs has previously dug up a very useful tool to make custom autocompletions.
Here's that in action:
...
0
votes
0answers
92 views
Implementing jacknife method
I need to use a jacknife method in order to find the standard deviation of my data. Howvere, I realise there's no built-in fuction (or maybe I couldn't find it), not even a general bootstrap method.
...
3
votes
1answer
77 views
Using OAuthClient to extend ServiceConnect service that requires authentication and POST
I want to extend the functionality of a service available via ServiceConnect, particularly Google Calendar to insert a new event.
That action requieres ...
9
votes
1answer
171 views
How to defer creating/displaying boxes in front end until requested?
If the size of an output expression is larger than threshold ByteCount, the front end will display an abbreviated version of it by producing an ...
2
votes
1answer
52 views
How can I find all the plot themes for a given function?
Plot themes are useful little things that ease the pain of manually styling Mathematica graphics. I have a few favorites, "Web", ...
8
votes
1answer
118 views
Exclude inactived functions from DifferentiationOptions
The list of functions provided in SystemOptions["DifferentiationOptions" -> "ExcludedFunctions"] show which symbols will not be touched by ...
13
votes
1answer
171 views
How is the Hessian computed using ``Experimental`NumericalFunction``?
Here and here it was explained how to use Experimental`NumericalFunction to compute the Hessian of a numerical function. I would like to know how this undocumented ...
5
votes
0answers
58 views
Testing for membership with Bags?
Is there a faster way to test for membership in an Internal`Bag other than unpacking the whole thing like this?
...
10
votes
1answer
194 views
Second argument of Internal`DoubleToString
Does anybody have an idea what the meaning of the second argument of Internal`DoubleToString might be? It accepts also a third argument which seems to be related to ...
10
votes
0answers
258 views
How to use Charting`ScaledTicks?
I found several topics about undocumented ScaledTicks function and tried to use this. Here is the first example:
...
7
votes
0answers
193 views
Undocumented TableView function
Seeking information on undocumented function TableView. Exempli gratia,
tab=Table[Table[If[Mod[i,Prime[j]]==1,1,0],{i,1,10}],{j,1,2}]
tab//TableView
$ $
...
7
votes
1answer
147 views
Internal`WithTimeStamps usage
I was digging inside the Iconize implementation a little bit and saw that there's a function BoxForm`BoxFormAutoLoad which loads ...
6
votes
1answer
110 views
Getting all system-level icons
Dispatch and InterpolatingFunction have these fun little icons on their summary boxes. How can I find the list of those?
