56 votes

What are some useful, undocumented Mathematica functions?

Sequential With From Daniel Lichtblau's comment there is a new undocumented syntax for With introduced sometime after version ...
46 votes

What are some useful, undocumented Mathematica functions?

System` The default value for the overhang parameter k (3rd argument) in ListCorrelate is ...
35 votes
Accepted

How to use Handler functions?

So I have a little bit more info, but mostly a learning technique we can test: Init I wanted to see when each of these was called so I made each possible handler (without a previous assignment) just ...
b3m2a1's user avatar
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33 votes

How can I work with RawArray?

This is a community wiki answer. Feel free to improve it. Introduction RawArray is an atomic array type that can hold data in any of the following formats: ...
32 votes
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How to use the iterator in Mathematica

Such functions set up a one-time iterator, i.e. a GeneralUtilities`Iterator. Its functionality may be inspected with ...
Michael E2's user avatar
  • 234k
31 votes
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Is Internal`StringToDouble broken in 12.3?

StringToDouble was renamed StringToMReal as part of code cleanup and the addition of several friends: ...
Itai Seggev's user avatar
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28 votes
Accepted

Why is SatisfiabilityCount faster than SatisfiableQ?

SatisfiableQ has three methods: "BDD": converts the expression to a BDD (binary decision diagram), "SAT": uses the Minisat library, "TREE": a branch-and-bound method based on the expression tree. <...
Adam Strzebonski's user avatar
27 votes

How to export an MXNet?

It seems the model file in MXNet (checkpoint) is defined by two files: a ".json" file and a ".params" file. The json file contains the definition of the network, and the params file contains the ...
xslittlegrass's user avatar
26 votes
Accepted

How to get old message formatting in version 11?

We can get old-style messages using Internal`$MessageMenu = False Needless to say, this is unsupported and undocumented functionality.
Szabolcs's user avatar
  • 234k
25 votes

What are some useful, undocumented Mathematica functions?

System`Private`*Entry* functions Since version 10.0 System`Private`SetNoEntry and ...
23 votes

What are some useful, undocumented Mathematica functions?

Not sure if a new question should be started, anyway, here's some undocumented syntax (sorted alphabetically): Collect Collect ...
23 votes

Bug with iterated With: Referring to function arguments invalidates previous definitions

A long comment: Automatic renaming again: ClearAll[F]; F[x_] := Hold[With[{a = x}, {b = x}, a]]; F[0] ...
Kuba's user avatar
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23 votes
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How can I determine the type of a packed array?

We can use one of several ways. First, let us create some test data: ...
Szabolcs's user avatar
  • 234k
22 votes

How to extract parts from atomic expressions like DelaunayMesh and Graph?

Motivation Recently, I wanted to extract parts of an atomic expression, and my first thought was to use a ToExpression/ToString ...
Carl Woll's user avatar
  • 130k
21 votes

What are some useful, undocumented Mathematica functions?

Undocumented option PlotPoints->{n,{p}} with 2(!) parameters n (number of points or Automatic) and p (list of critical points) example ...
20 votes

Language`* documentation project

Language`*Mutation* First seen here, implemented by Taliesin Beynon What do they do? The only functions I really know about in this bunch are the ...
b3m2a1's user avatar
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20 votes
Accepted

Why does setting SyntaxInformation add a definition to DefaultValues

In my view, the Mathematica front end would have needed a complete rewrite a long time ago to be in a shape where it can compete with modern UI's. Looking at MATLAB, it's clear that you always find ...
halirutan's user avatar
  • 113k
19 votes

What are some useful, undocumented Mathematica functions?

Simplify`PWToUnitStep: ...
19 votes

What is the complete list of valid FrontEnd Packet types?

I thought I'd keep a running tally of what I know about these packets (excluding the obvious ones like CreatePalettePacket) just for reference. Text / Box ...
17 votes

What are the main differences between RawArray and PackedArray?

Here goes my conjecture but I would welcome any opinion or clarification by people in the know. PackedArray stores data in a computation-efficient way. It still ...
The Vee's user avatar
  • 1,790
17 votes
Accepted

Is there any difference between Quiet and Internal`DeactivateMessages?

Internal`DeactivateMessages[expr, msg1, msg2, ...] evaluates expr after turning off the given messages. When the second argument ...
ilian's user avatar
  • 25.5k
17 votes

What's purpose of the Internal`ToEquivalenceClass

Internal`ToEquivalenceClass[expr, tol] is used to replace floating point numbers in an expression with their equivalence class representatives according to the ...
ilian's user avatar
  • 25.5k
17 votes

Language`* documentation project

Language`*ExpressionStore This is a hash-map system (without vectorized calls) that stores items without incrementing the ref count allowing them to be garbage ...
17 votes
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Can't make more than 249 Internal`Bags in a Table

Seems to be the same underlying issue as here: by default, Table compiles its argument when the number of values is 250 or more. Evidently ...
Chris K's user avatar
  • 20.1k
15 votes
Accepted

Reduce ODE into 1st order

Introduction I thought I would present a way to leverage built-in functions to do this. I've known for a long time that NDSolve sets up an ODE problem as system of ...
Michael E2's user avatar
  • 234k
15 votes

Using DocumentationBuild and Transmogrify to generate web docs

tl;dr The Workbench packages are out-of-date for 11.1 and the whole system is not configured to easily work from Mathematica using a structure differing from the standard ...
b3m2a1's user avatar
  • 46.8k
15 votes
Accepted

How to use Streaming package in v11.1?

The patch Here is a way to get Streaming` working: on a fresh kernel execute the following: ...
Leonid Shifrin's user avatar
15 votes
Accepted

A more appropriate way to use RuntimeTools`Profile

Update Here's a new version that doesn't require a stylesheet: ...
Carl Woll's user avatar
  • 130k
15 votes
Accepted

What happened to SequenceLimit?

SequenceLimit became NumericalMath`NSequenceLimit. In the past, that change broke some of the examples on ...
Chris Chiasson's user avatar
14 votes
Accepted

Would it be a good idea to use Failure and FailureQ in own code

What I personally usually do is to still use $Failed / exceptions when a returned $Failed / thrown exception can't be used ...
Leonid Shifrin's user avatar

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