Questions tagged [undocumented]
Questions on undocumented functionality of Mathematica. Note that such functions might be subject to change without notice in future versions.
290
questions
9
votes
1
answer
100
views
Arithmetic operations on NumericArrays
Currently, NumericArrays are directly supported by the most important array-related functions, what makes them a very attractive data structure for implementing ...
- 55.8k
10
votes
1
answer
256
views
What is idiomatic way to extract NumericArray from Image?
It is easy to see that NumericArray is a construct underlying Image:
...
- 55.8k
10
votes
1
answer
97
views
How to list all possible string arguments of a specific function?
For example, to learn the function Alphabet, we can read its document. But it's rather ambiguous, like "Some languages have extra properties". How to find ...
- 266
1
vote
1
answer
36
views
How to use System`Private`AssumptionAccess and Assumptions`*?
I see this function is used by some symbols in Assumptions`*, and it HasDownCode and does not ...
- 1,463
1
vote
1
answer
240
views
Internal`CopyListStructure makes fatal error sometimes
Warning : At least in my PC (windows 10, mathematica V12.2), some of the codes here led to fatal error.
Fatal means mathematica will freeze + 'Abort Evaluation' will not work. I had to quit the kernel ...
- 2,451
6
votes
1
answer
108
views
What is the purpose of StrokeForm?
Symbol System`StrokeForm is present already in Mathematica version 8 (but not in version 5.2).
Currently, it is used in built-in themes, for example:
...
- 55.8k
14
votes
1
answer
329
views
Wrong Graphics coordinate system after Image to Graphics conversion
Bug persisting through 13.0.0 [CASE:4896512]
If I upload this image (originally this img was generated by EdgeDetect) by normal ...
- 23.4k
3
votes
1
answer
111
views
How to explicitly open or close cell group?
There is a "OpenCloseGroup" in FrontEndTokenExecute. It act like toggle. If the selected cell group is open, ...
- 15.6k
3
votes
0
answers
77
views
How to convert Graph atomic object back into unevaluated expression? [duplicate]
For the purposes of further development of my shortInputForm function, I wish to convert Atomic objects such as Graph into non-...
- 55.8k
4
votes
1
answer
94
views
Resolve absolute path to Documentation Notebook
We can easily create clickable hyperlinks for Documentation pages like the following:
{URL["paclet:ref/Set"], Hyperlink["paclet:ref/Set"]}
But ...
- 55.8k
7
votes
1
answer
125
views
What Does Compile`SetIterate Do?
The list of compilable functions (given by Compile`CompilerFunctions[] // Sort) shows one of the more interesting- and core-sounding functions: ...
- 1,577
0
votes
0
answers
24
views
What is the function of "PreviousFunctionTemplate" and "NextFunctionTemplate" defined in "KeyEventTranslations.tr"
In the system file "KeyEventTranslations.tr" are two undocumented frontend tokens "PreviousFunctionTemplate" and "NextFunctionTemplate" and I wonder what they do.
...
- 1,167
4
votes
0
answers
49
views
What are the valid options for the "ParametricCaching" option in ParametricNDSolve?
I am using ParametricNDSolve as part of the calculation of an objective function for an optimization, so I am trying to strike a balance between memory usage and ...
- 13k
3
votes
0
answers
27
views
Modern equivalent of $InternetProxyRules
The undocumented symbol $InternetProxyRules was useful for debugging network connectivity issues. In Mathematica 12.0 it returns a list with keys "UseProxy&...
- 7,428
21
votes
1
answer
776
views
Is Internal`StringToDouble broken in 12.3?
I believe Internal`StringToDouble was the only way to fast convert string into numbers. Now in V12.3 it was removed:
Internal`StringToDouble["1"]
...
- 25.3k
2
votes
1
answer
73
views
How to set MaxStepSize for the case of two variables
The option MaxStepSize permits to manually set the step size of the integration in NDSolve and similar functions.
How do I set ...
- 6,114
0
votes
1
answer
77
views
TemplateEvaluate, TemplateUnevaluated, and TemplateVerbatim [Undocumented] - What do you know?
Let's discuss some undocumented Template-related functionality. Specifically, what do you know about TemplateEvaluate, ...
- 555
5
votes
1
answer
205
views
NDSolveValue and pdepe of MATLAB disagree under spherical coordinates
Assuming there is a spherical activated carbon particle, the concentration outside the grain is 200 (C[t,ri] == 200), that ...
- 53
6
votes
1
answer
88
views
Turning off automatic hyperlinks
Recently (I only noticed in V12.2), website URLs, such as https://www.wolfram.com, became active in text cells in notebooks. The "hot" nature makes the links hard to edit, since any click ...
- 213k
6
votes
0
answers
57
views
How to revert behavior of SeriesData to pre 12.1
In Mathematica 12.0 and earlier,
SeriesData[x, 0, {1/u + Log[x/y]}, 0, 3, 1]
used to preserve its list of expressions in the form it was given.
Now, in ...
- 19k
5
votes
1
answer
148
views
Property "Centroid" of result from ConvexHullMesh[] can not be extracted
As the title describes, specifically, simple code below
ConvexHullMesh[RandomReal[1, {10, 2}]]["Centroid"]
returns an error in V. 12.2, but it worked in ...
- 9,273
0
votes
1
answer
112
views
Log scale for ListContourPlot when the axes have different orders of magnitude
I am trying to plot a data set (download here) in Mathematica (it's 3.9 MB and I wasn't sure how to best share it) which I then want to visualize with ...
- 952
8
votes
1
answer
364
views
Please explain this syntax: GaborWavelet[6]["FourierFactor"]
I've been using Mathematica for some years, yet I'm befuddled by this statement:
GaborWavelet[6]["FourierFactor"]
It appears to give the center frequency ...
- 285
9
votes
2
answers
268
views
BarLegend ticks distorted in MatrixPlot
As shown in many threads here (this, this, ...), Ticks is a valid option of BarLegend. But it doesn't seem to work well in this ...
- 4,006
2
votes
1
answer
204
views
Experimental`CreateNumericalFunction
When working with a Compile function I can specify if a given argument is a matrix, a vector or a scalar. For instance, something like:
...
- 457
6
votes
0
answers
136
views
A Curiosity: What is DispatchQ?
As shown below, my autofill in Mathematica showed an interesting function: DispatchQ. Yet, it does not appear in the Mathematica Documentation Center, a search for ...
- 1,577
3
votes
0
answers
90
views
Why are some symbols recognized by Mathematica but nowhere in the documentation? [duplicate]
I was trying to calculate a Groebner basis for a given set of polynomials, and I did it successfully. But I wanted to calculate the conversion matrix between the original basis and the Groebner basis....
- 131
6
votes
1
answer
141
views
Implicit Riccati Equation Solver (to find the anti-stabilizing solution)
I've found that the latest MATLAB icare() solver includes the possibility to find also the anti-stabilizing solution of the Riccati equation.
I haven't found a ...
- 2,058
5
votes
0
answers
64
views
What does the PerformanceGoal option of FindMinimum do?
FindFit and FindMinimum both have a PerformanceGoal option. It is not documented. What does ...
- 224k
4
votes
1
answer
162
views
In search of lost time: Mathematica keyboard shortcuts
I am wondering about all the shortcuts that there are in Mma, besides the documented ones in https://reference.wolfram.com/language/tutorial/KeyboardShortcutListing.html.
Are there any undocumented ...
- 743
7
votes
1
answer
126
views
Is AlgebraicRulesData magical?
I am trying to understand what AlgebraicRules is all about in the answer to this question. It apparently returns an ...
- 19k
15
votes
1
answer
244
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 ...
- 19k
1
vote
0
answers
97
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:
...
- 609
5
votes
1
answer
179
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 ...
- 30.3k
5
votes
1
answer
116
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, ...
- 55.8k
19
votes
1
answer
162
views
Why does setting SyntaxInformation add a definition to DefaultValues
Before setting any definitions to the symbol f, the DefaultValues of f is empty:
...
- 19k
5
votes
1
answer
75
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
1
answer
139
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 ...
- 457
5
votes
0
answers
137
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 ...
- 14.7k
1
vote
1
answer
125
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 ...
- 11.3k
4
votes
1
answer
146
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 ...
user67126
6
votes
1
answer
125
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 ...
- 17.6k
3
votes
1
answer
266
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(...
- 2,058
8
votes
1
answer
167
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 ...
- 17.6k
13
votes
1
answer
178
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...
- 17.6k
11
votes
0
answers
154
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 ...
- 51.6k
5
votes
1
answer
190
views
MatrixConditionNumber does not work in version 12.0
A = {{1., 0.}, {0., 2.}};
LinearAlgebra`MatrixConditionNumber[A]
- 71
3
votes
1
answer
234
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 ...
- 1,139
5
votes
0
answers
133
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 ...
- 2,383
7
votes
1
answer
60
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 ...
- 45.4k