Questions on Mathematica's scoping constructs (Block, Module, With, etc.)

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3
votes
2answers
112 views

Module, local variable

Lets say I define a Module, that internally use iterating in a Table or Do, say something ...
1
vote
1answer
84 views

Module inside module in `Compile`

How can I make compilation to go through with a module inside module? I tried this, failed, a few other ways failed too. ...
0
votes
0answers
62 views

Is tensor argument passing to module expensive?

I wrote a simple module which is supposed to do recursive computation, however it turns out to be expensive even for 300 points. I am not sure why is it slow, all the computations seem to be ...
23
votes
1answer
228 views

Strange behavior with Cases and Position with SetDelayed

I feel like I must be missing something simple and obvious here, but this has me scratching my head. This works as expected: ...
5
votes
3answers
242 views

Turning an expression into a function inside another function

Say I have an expression g=Sin[q]; It is easy to turn it into a function, and to perform manipulations on this function (this and variants of this were discussed ...
7
votes
2answers
110 views

Cannot Block Plus

It is customary to use the following idiom to partially evaluate something inside a held expression: ...
3
votes
2answers
110 views

Sections with unidirectionally shared variables

I have 2 sections is my notebook: ...
18
votes
1answer
258 views

A With expression local variable specification without head List

I just noticed a new form of With in its documentation: With[$x=x_0$, $expr$] specifies that all occurrences of the symbol $x$ in $expr$ should be replaced ...
2
votes
0answers
74 views

Scoping all symbols

After working Mathematica for a couple weeks to write a larger program, beyond doing integrals, I am starting to gain an appreciation for the Wolfram Language. There are a couple issues that drive me ...
1
vote
0answers
19 views

Manipulate inside Module - “Order of evaluation conflicts” [duplicate]

In this example, Manipulate is contained within a Module: ...
3
votes
2answers
133 views

How to use locally scoped dynamic variables in Manipulate for expression and control parameters

I have a Manipulate that has dynamic variables that I want to use in the displayed expression and use in the parameters for the manipulate controls. I only ...
1
vote
0answers
85 views

Should I Remove the initial symbols of Module?

Often we use Module to construct complicate function. Consider that Module create new vars every time we run the function, should I remove the initial values at the end of Module-function?Or should I ...
3
votes
0answers
38 views

Cross referencing symbols in different packages [duplicate]

I have problems with name space shadowing which I do not know how to resolve. I have two packages which depend on each other. Here is example of two files fooPackage.m: ...
2
votes
1answer
77 views

How to write a function that returns the combined output of several built-in functions

I am trying to make a module that takes a Boolean function, and prints the following: the function's truth table the function's NOR epxression the function's minimal Disjunctive normal form So far ...
-1
votes
1answer
106 views

Module whose input is a function of 2 variables [closed]

I need to make a Module whose input is a function of 2 variables and 2 variables m,n so i can make a Matrix with Array. Basicaly, I need this: ...
0
votes
1answer
47 views

Behavior of custom file chooser code changes when placed inside DynamicModule

My primary objective is to build a file chooser that aides a user in selecting files into one of two categories. Files can be individually selected, or based on the clicking of a specific checkbox, ...
5
votes
1answer
113 views

Dynamics and Block interfere

As mentioned by Albert Retey in a comment, we can unintentionally interfere with our dynamics as follows ...
0
votes
1answer
94 views

Basic (?) dynamic module questions (If clause and refresh problems)

I'm building a dynamic module, but I'm stuck with a few things i don't know how to deal with. In particular I'm stuck with the "If" sentence and the refresh inside the dynamic module. Here's a ...
1
vote
0answers
36 views

Module does not evaluate the same way as without [closed]

I have a module as follows: ...
1
vote
1answer
58 views

Module and Manipulate: Why the Red Highlighting? [duplicate]

If I define a function that returns a Manipulate object, and the Manipulate has a local variable inside of it, the local ...
0
votes
2answers
255 views

Use a Module to return multiple plots

A program I'm running requires me to generate multiple plots over the same domain, so I thought it would be fairly simple to use a module and bury all of the plot commands within that that way I only ...
3
votes
2answers
155 views

Memory Problem with Modules and NDSolve

I'm using NDSolve inside a module, and I appear to have a memory leak. The relevant code is: ...
1
vote
1answer
251 views

Combining Mandelbrot and Monte Carlo

I'm trying to combine plotting a Mandelbrot set with Monte Carlo randomization to plot an equation using random points for complex number z, for the function $z^3-2z+2=0$. Below is the code I have ...
1
vote
2answers
126 views

Random walk using Module [closed]

I want to create a random walk using Module. The walk start at {0, 0}. At every step, x ...
4
votes
1answer
111 views

Unwanted interaction between instances of a Manipulate function

The function trajectory below is defined in terms of Manipulate and calls the auxiliary function ...
3
votes
0answers
85 views

Decrease computation time of module [closed]

I need to compute the exponential of a matrix (in this caseR) by the summation method where R is a square matrix with symbolic ...
12
votes
1answer
321 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 ...
14
votes
3answers
275 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 ...
17
votes
2answers
410 views

Messages leak out from Block

Bug introduced in 8.0 or earlier and fixed in 10.1 When assigning message to a symbol localized by Block, I would expect that this message is not accessible ...
2
votes
1answer
51 views

Local function becomes global after Plot [duplicate]

In the code below, I define and plot a local function f. Clear[f] Module[{f}, f[x_] := 1; Plot[f[x], {x, 0, 1}]] However, ...
2
votes
1answer
77 views

Writing a procedure that invokes Manipulate[]

I would like to write a procedure with the signature: Foo[vars, params] which produces a Manipulate object. The procedure ...
19
votes
2answers
551 views

I define a variable as local to a module BUT then the module uses its global value! Why?

I have a question about modules and local variables. Here's my example: h = 5; Module[{a, h}, a[h_]= h^2; a[4]] (*Out[2] = 25*) I expected the module to ...
4
votes
1answer
182 views

ControlType -> None Vs. Module inside Manipulate (i.e. making everything local)

I'm building a program on another one made available in the Wolfram Demonstration Project. I've noticed that in the original code (working flawlessly) many variables were made local inside the ...
5
votes
1answer
112 views

Module does not remove a function definition

The following is a minor variant of the function uniqueTuples as given by Simon Woods in this answer. ...
15
votes
2answers
377 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 ...
5
votes
4answers
291 views

Replacing parts of a matrix

I'm a beginner to Mathematica and to writing scripts in general. I'm currently trying to write a code that will take any element in a matrix higher than a certain threshold value n and set it equal to ...
2
votes
1answer
44 views

Substitution breaking the scope

A novice's problem, perhaps: it seems that /. substitution does weird things to the scope. ...
2
votes
2answers
169 views

Expressions containing globally undefined symbols inside a function where they are defined

Consider the following code. f[a_,b_]:=x; Clear[a,b]; x=a+b; f[1,2] It returns a+b. However, from a certain viewpoint, one ...
1
vote
2answers
95 views

Localised variable shows up as Global [duplicate]

Why does this local variable show up as Global? ?q Information::notfound: Symbol q not found. >> ...
-7
votes
2answers
158 views

Module function corrupts string? [closed]

I have the module who should replace some elements of a matrix with checkboxes ...
2
votes
1answer
70 views

How to protect function variables [duplicate]

I am sure this has been asked before, but I can't seem to find the right solution. I want a function to be the solution to a differential equation ...
5
votes
2answers
239 views

A better way of handling Module output?

I am sure this has been asked before in a way or another. I need to Save or DumpSave some symbols that contain the result of ...
1
vote
1answer
53 views

Global variales, Paralell computation and Limiting notebook's contex

If I limit the context of each notebook: and use parallel computation: ParallelTable[ToExpression["b" <> ToString[j]], {j, 1, 10}] then after ...
9
votes
2answers
230 views

How to assemble and disassemble a function into steps

I've watched many programmers (both novice and expert) write functions in Mathematica and have observed a common behavioral pattern. This pattern has many elements that would be automated and thus ...
0
votes
0answers
104 views

Best practices for breaking up functional blocks?

Say I have a main function that does some job, and I'm only interested in the final result of ans, i.e., the local functions are not important and produce no side-...
3
votes
1answer
72 views

Should “counters” used in Do, Table, … within Module be declared as local?

I have little to no understanding of how Mathematica handles scoping, so the question may seem a little bit funny. What is the preferred way: ...
3
votes
2answers
252 views

Strange interaction between Module and ListPlot

Bug introduced in 10.0 and fixed in 10.1 Why is the variable a ending up assigned to {1,2,3} after executing Module[{a}, a=Range[3]; ListPlot[a] ]
1
vote
1answer
229 views

NDSolve inside Module with local variables

I want to use NDSolve within a Module and output the solution at some times. (Mathematica 10) All works fine with global variables (symbols) ...
4
votes
1answer
128 views

Defining a function that prints both the name and value of a variable defined locally within the calling function

To save time when debugging with Print statements, I'd like to define a function -- call it PrintVal -- that prints both the name and value of a variable defined locally within the calling function. ...