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

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17
votes
1answer
181 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 ...
0
votes
0answers
17 views

How to get rid of numerical scope error? [duplicate]

I am trying to perform a numerical maximization routine on a setdelayed function which involves a numerical integral and I'm getting an error message. The evaluation continues and gives the right ...
2
votes
0answers
58 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 ...
9
votes
2answers
181 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 ...
1
vote
0answers
15 views
3
votes
2answers
66 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 ...
3
votes
0answers
35 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
47 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
vote
2answers
114 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 ...
15
votes
0answers
221 views

Compile not correctly initializing a variable defined inside Module

Bug introduced in 8.0 and persisting through 10.1.0 or later In the following example, inside the minimumX's Module, ...
-1
votes
1answer
64 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
29 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, ...
46
votes
5answers
1k views

How to avoid nested With[]?

With[ {v1 = #}, With[ {v2 = f[v1]}, g[v1, v2] ] ] How to avoid nested With[] like the above? I'd like to use ...
125
votes
7answers
5k views

What are the use cases for different scoping constructs?

Mathematica includes three functions that I know of which can be used to effectively (if not actually) define a variable and give it a value within a local scope: ...
5
votes
1answer
80 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
60 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
29 views
12
votes
2answers
541 views

Syntax highlighter shows error for Manipulate when it's inside a Block or a Module

I'm putting my new copy of Mathematica 10 through its paces and I noticed a weird change in the colouring scheme that I find very annoying, and I'd like to get some insight into why it's happening. ...
1
vote
1answer
36 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
76 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 ...
14
votes
2answers
370 views

Messages leak out from Block

fixed in 10.1 When assigning message to a symbol localized by Block, I would expect that this message is not accessible outside of ...
0
votes
0answers
45 views

What is the right way to combine a Package, Module, ParallelTable and NIntegrate?

I am stuck with a curious problem. I would like to to have a package from which i can call a function test[path], which then performs a time consuming numerical ...
1
vote
1answer
171 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 ...
3
votes
2answers
99 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
2answers
101 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
103 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
69 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 ...
8
votes
1answer
164 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 ...
3
votes
2answers
172 views

Strange interaction between Module and ListPlot

Why is the variable a ending up assigned to {1,2,3} after executing Module[{a}, a=Range[3]; ListPlot[a] ]
9
votes
2answers
156 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 ...
4
votes
3answers
557 views

Defining a new Function using RegionPlot

I'm trying to make images like this: to illustrate 2D integrals to a calculus class. I used the code ...
2
votes
1answer
43 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, ...
3
votes
0answers
92 views

Why is it not allowed to define vectors of variables in a scoping construct?

The following command assigns 1 to a, 2 to b and 3 to c: ...
2
votes
1answer
68 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 ...
14
votes
2answers
435 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
120 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 ...
15
votes
2answers
308 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
1answer
99 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. ...
9
votes
1answer
167 views

Temporary variable not removed in Mathematica 10

Bug introduced in 10.0.1 and fixed in 10.0.2 In Mathematica 10, the documentation still states that a symbol with attribute Temporary will automatically be removed when it is no longer needed. Now ...
5
votes
4answers
268 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 ...
8
votes
1answer
145 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 ...
2
votes
1answer
43 views

Substitution breaking the scope

A novice's problem, perhaps: it seems that /. substitution does weird things to the scope. ...
1
vote
2answers
87 views

Localised variable shows up as Global [duplicate]

Why does this local variable show up as Global? ?q Information::notfound: Symbol q not found. >> ...
-4
votes
2answers
98 views

Module function corrupts string? [closed]

I have the module who should replace some elements of a matrix with checkboxes ...
2
votes
1answer
60 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 ...
4
votes
2answers
188 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
51 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 ...
3
votes
1answer
62 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: ...
0
votes
0answers
55 views

Where to put manipulate brackets for slider effect to refresh page

In order to move the plane of a best fit around to alter the sum of the residuals, I have decided to pick on one point and attach a slider to it, this adds a little variance and moves the table ...