Questions about contexts, which are used in Mathematica to organize defined symbols and avoid conflict between symbols that would otherwise have the same name. They are created when packages are loaded.

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57
votes
6answers
3k views

What is the most convenient way to read definitions of in-memory symbols when we don't have the source files? (Spelunking tools)

Note: I put Simon's implementation on GitHub. Contributions welcome! When trying to read the definition of already defined (package or built-in) symbols using ...
35
votes
1answer
1k views

Local variables in Module leak into the Global context

From the Mathematica documentation on Module: Module allows you to set up local variables with names that are local to the module. But after using ...
23
votes
3answers
1k views

How to load a package without naming conflicts?

This question applies to any package, but I encountered this problem while working with graphs. There are symbols in the Combinatorica package (such as ...
21
votes
1answer
2k views

Why are some function names red?

I need to evaluate Needs["GraphUtilities`"] before I can use functions such as GraphPath[]. When I do so, some functions get ...
21
votes
2answers
161 views

How can I evaluate untrusted Mathematica code in a sandbox?

Is there any way to build a sandbox to evaluate untrusted Mathematica expressions in order to prevent them from having (malicious or accidental) harmful side effects? Context: I'm developing a system ...
21
votes
2answers
501 views

Context unique to each group at a specified level

Are there any new tools in v10 that might be applicable to this problem? Recent versions of Mathematica provide the option of having a unique $Context for each ...
16
votes
4answers
358 views

Result about Context is inconsistent with the description of “Power Programming with Mathematica”

x = 5; temp`x = 6; Begin["temp`"] {x, Global`x, temp`x} The result in my Mathematica session is {5,5,6}, but it's ...
15
votes
2answers
202 views

How to find the package file that stores a certain symbol?

Is it possible to figure out in what file a certain packaged symbol lives in (assuming there is no shadowing between multiple identical symbol names)? I would like to have a function that if, given a ...
14
votes
1answer
422 views

Is it possible to use Begin and End inside a Manipulate?

May be someone can explain why I can't use Begin["context`"] and End[] inside a Manipulate ...
14
votes
2answers
181 views

How to find out what files are touched when Get is called?

Is there a way to capture all package files touched whenever a package is called via Get, Needs, ...
14
votes
1answer
216 views

Global` context not empty at startup in v10.2.0

Bug introduced in 10.2 and persisting through 10.2 or later Note that the analysis of this problem revealed a different problem than in Potential pollution of Global` context in fresh kernel (see ...
14
votes
1answer
245 views

Potential pollution of Global` context in fresh kernel

Bug introduced in 10.0.0 and fixed in 10.0.1 If I evaluate, with a fresh kernel Names["Global`*"] I get {"rhs", "z"} ...
13
votes
2answers
326 views

Why does leaving and re-entering a context lose values defined in that context?

I'm getting unexpected behavior when beginning a new context, leaving it, and then re-entering it. Specifically, when re-entering the context, symbols that had been previously defined in that context ...
13
votes
4answers
744 views

Strategies for avoiding and handling shadowing

When dealing with namespaces in Mathematica (BeginPackage, $ContextPath ...) one is unavoidably confronted with the problem of ...
11
votes
3answers
214 views

Creating a custom context with a Hold construct

I'm trying to create a function "InContext" to execute a piece of code inside a certain context (and to return the result of evaluating that piece of code). One approach is to place the code inside a ...
11
votes
2answers
217 views

Globally loading packages while using a CellGroup as the default context

I have a notebook I wish to set up where the sections are conceptually related to each other. But, I wish to isolate them from each other programmatically, so that they do not interfere with one ...
10
votes
2answers
277 views

How to abbreviate context names?

It's convenient to abbreviate often-used function names, eg Dim = Dimension. Is it possible to abbreviate long context symbols, e.g. Combinatorica when the context ...
10
votes
2answers
195 views

For any symbol, how can I get the full context-qualified name of the symbol as a string?

I'd like to have a function, whether built-in or not, that when given a symbol, whether bound to a value or not, returns a string giving the context and name of the symbol. Example: ...
10
votes
1answer
186 views

Importing an mx file into a context

Consider the following simple code which dumps the global context: var = 5; DumpSave["test.mx", "Global`"]; Now, in a new notebook, I would like to import var in ...
10
votes
1answer
156 views

Is there a way to find out who is importing a package?

After calling some functions, if I look into $ContextPath, I can see that JLink` is in there. Is there a way to find out what ...
10
votes
1answer
202 views

Future-proofing access to packed array tools

Most of the Mathematica users beyond beginner level will be aware of the phenomenon of Packed Arrays. The user-accessible functions related to packed arrays live in the ...
10
votes
2answers
104 views

Functions in a different context are replaced with infix forms of their namesake in System`

So, in an attempt to help out Fabian with his question, I did what I often do, and created a new symbol in the Pillsy` package that I could play with. Since it was ...
10
votes
2answers
183 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 ...
9
votes
2answers
175 views

What are the purposes of functions in FrontEnd` context which are duplicates of those in System`?

I noticed that for notebook-related heads, there are usually a pair of same functions, one in System context, another in ...
9
votes
2answers
183 views

How to define UpValues in a different context from within a package

I'm trying to create a function (in a package) to import a lot of data and create a symbol with UpValues to return specific results about the data. I've got it working fine in a regular notebook, but ...
9
votes
1answer
3k views

How do I create and use Mathematica packages?

I have created a package following the tutorial in Mathematica 8 virtual book. However this tutorial is quite, let's call it, "short". I have a TestPackage.m file: ...
9
votes
3answers
233 views

Functions that creates symbol in a specific context

I'm trying to make a function f that takes a symbol, a value, and a context, and creates the symbol in the requested context and assigns it the passed value. The ...
9
votes
2answers
158 views

How does $CellContext` work?

The only official info about $CellContext` I was able to find is: placeholder for the context of a symbol inside Dynamic ...
9
votes
2answers
361 views

Why doesn't DumpSave work for elements created within a local notebook context?

I recently noticed that when dealing with notebooks with local context, I cannot successfully DumpSave variables, or, rather, when I call ...
8
votes
2answers
218 views

The introduction for Context in Wagner's book is out of date? [duplicate]

In Section 8.1.1 (P230 of the book, P249 of the PDF) of Wagner's book, the following example is shown: x = 5; temp`x = 6; Begin["temp`"]; {x, Global`x} The ...
8
votes
3answers
618 views

How can I make private functions inside packages

I want to make private functions.for that purpose,I wrote the following code. BeginPackage["Test1`"] Begin["`Private`"] function1[x_]:=x End[] EndPackage[] I ...
8
votes
2answers
638 views

How to properly handle mutual imports of multiple packages?

I'm new to the mathematica platform and I am developing a simulation framework as my first exercise and have been tearing my hair figuring how to make packages interact with each other. Ill explain a ...
8
votes
1answer
171 views

Context of localised (dynamic) symbols

When you localise a symbol with Module, the created unique symbol is usually in the current context. There seems to be an exception to this which has further ...
7
votes
6answers
618 views

How can you give a Module a context and have its local variables and Modules belong to that context?

What would be the best way to give a module its own context and have its local variables and Modules belong to that context?
7
votes
1answer
152 views

Organizing similar datasets using Contexts or otherwise

I often import several long time series to analyze something about a city. When I have multiple cities, I use contexts. As a simple example, ...
7
votes
2answers
128 views

Inserting symbols' definitions during read time of the code

Let's say we've got a package: ...
7
votes
1answer
212 views

What is the purpose of Dump contexts?

Motivation I've been trolling through some internal code, trying to glean design practices WRI developers employ when extending Mathematica using top-level code. During my ...
6
votes
3answers
269 views

Scope within Context

To define some package-wide functions/variables, what approach is recommended? I tried to use contexts with the Begin function, but this failed: ...
6
votes
0answers
86 views

Does one need to be careful about loading multiple (many) contexts or packages in the same session?

I have a number of large pieces of precomputed data which I am considering putting into individual packages in order to load them (via DeclarePackage) and unload ...
5
votes
2answers
207 views

Delete contexts from a string representation of a symbol

I want to delete the string representing the context of a symbol. For info I need such a functionality in my ShowIt function defined here I'd like to know how I ...
5
votes
1answer
89 views

Naming conflicts with Dummy variables in several packages conflicts

I'm using several packages in a notebook. In each packages there is functions defined with dummy variables. When I load the several packages in my session, i've got a warning message: ...
5
votes
1answer
56 views

Update/refresh notebook variable color on clear

By default, Mathematica displays variable names already assigned as black while new variables are displayed in blue. When executing Clear["Global`*"], variables ...
5
votes
2answers
183 views

Package Loading: How to get rid of Needs::nocont?

I am trying to create a documentated application inside FileNameJoin[{$UserBaseDirectory, "Applications"}] I obviously dont fully understand the concept of the ...
5
votes
0answers
44 views

How is CellContext->CellGroup supposed to work?

After reading the documentation on the subject, I still cannot get CellContext->CellGroup to work. Here's a simple example. (Unfortunately, I cannot easily ...
4
votes
1answer
984 views

FeynCalc “May shadow or be shadowed by other definitions”

So I've downloaded the latest FeynCalc from this site and put the extracted folder in user/me/library/Mathematica/application, but when I write the command ...
4
votes
1answer
136 views

Copying a symbol using a subpackage

In this question, there is a beautiful method to copy a symbol. However, i'm not able to use it as an addon to my package. So the main question is How to rename/copy a function defined in a ...
4
votes
0answers
43 views

When I run multiple Mathematica programs from terminal, are they supposed to use different Kernel?

Since I found that when I using notebook interface, I need to assign different kernels to different notebooks (if I want to run them at the same time), I wonder if I run those *.m files from terminal ...
4
votes
0answers
65 views

Variable not assigned to correct Context [duplicate]

I am trying to understand Mathematica's Context, but I do not understand why the short name of the variable defined in the temp` context (x) returns the Global definition. I am following the section ...
3
votes
1answer
260 views

Errors when using ParallelTable inside a package

I'm developing a package that contains a function that requires evaluation of an expensive Table, so I use ParallelTable ...
3
votes
2answers
98 views

Sections with unidirectionally shared variables

I have 2 sections is my notebook: ...