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

learn more… | top users | synonyms (1)

2
votes
2answers
44 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
0answers
55 views

Combining Mandlebrot and Monte Carlo

I'm trying to combine plotting a Mandlebrot set with using 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
85 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
91 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
53 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 ...
7
votes
1answer
106 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 ...
9
votes
2answers
125 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 ...
12
votes
1answer
213 views

Messages leak out from Block

When assigning message to a symbol localized by Block, I would expect that this message is not accessible outside of Block, but ...
2
votes
1answer
37 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
63 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 ...
13
votes
2answers
365 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 ...
2
votes
1answer
78 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
91 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
274 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
242 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
42 views

Substitution breaking the scope

A novice's problem, perhaps: it seems that /. substitution does weird things to the scope. ...
1
vote
2answers
84 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
89 views

Module function corrupts string? [closed]

I have the module who should replace some elements of a matrix with checkboxes ...
2
votes
1answer
54 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
176 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
47 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 ...
8
votes
1answer
130 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 ...
3
votes
1answer
59 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
48 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 ...
0
votes
1answer
36 views

Fit inside a module [closed]

I have here a MMA NB which works fine outside the MODULE. BUt in the module routine there comes up an warning that the solution is not real. Can anyone here help please? ...
3
votes
2answers
129 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] ]
1
vote
1answer
87 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) ...
3
votes
1answer
71 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. ...
6
votes
1answer
231 views

A smarter nested With?

I often find myself writing code that looks a bit like this: ...
3
votes
1answer
77 views

Hiding body of a module or function in mathematica

Is it possible to hide the body of a module or function in MMA? For example I would like to turn this: myModule[]:=[{}, Body of module ] to: ...
1
vote
2answers
62 views

How do I localize an assignment to expression (instead of symbol) within scoping construct?

Is it possible to localize an assignment to an expression (defined via UpSet) instead of a Symbol within a scoping construct? ...
8
votes
1answer
130 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 ...
1
vote
2answers
65 views

Assigning to the “local” version of a symbol

Compare Manipulate[c[1] = 1; c[1], {c[1], 0, 1}] with Manipulate[Do[c[i] = 1, {i, 1}]; c[1], {c[1], 0, 1}] The first case ...
4
votes
3answers
159 views

Altering values in Manipulate with dynamically generated controls

I have a Manipulate whose controls are generated based on a parameter in a containing Manipulate: ...
0
votes
2answers
68 views

Use conditional expression inside With

I want to assign a number to an internal variable, depending if a specific option has been given, but it seems to fail. Something like: ...
2
votes
1answer
110 views

Odd problem with Module

I've been having a strange problem with Module. Oddly it seems to be linked to my use of Import and then applying a function such as Flatten to my Import. I pasted images of my code and output ...
1
vote
2answers
64 views

Is there a way to logically test an optional color input inside a module? [duplicate]

Suppose I create a Module that is expected to return a graphic that I will later use in a plotting procedure (e.g., with ...
0
votes
1answer
78 views

Substitution of a function in a differential equation

Suppose we have a differential equation as follows: g[t_] := t/2 m[t_] := t/3 A[t_] := {{g[t], 1}, {1, m[t]}} p'[t] == A[t]. p[t], p[0] == {1, 0} ...
3
votes
1answer
78 views

Evaluating arguments of module (inside compile)

Note: this is a clarification of 2 earlier unanswered questions, Compile issues, scoping and order of evaluation and Optimising a simple computation with vectors . The problem I have a list of ...
2
votes
1answer
97 views

Manipulating parameters in a complex algorithm

I have a complex algorithm that depends on: A wavelet basis A number of sampling points out of a distribution A thresholding value I want to be able to play with different scenarios using ...
3
votes
0answers
82 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
0answers
90 views

Compile issues, scoping and order of evaluation

I have a few questions about compiling functions, which I think are all related to scoping and order of evaluation. I will illustrate them by a minimal example of the problem I have. I'm sorry for ...
0
votes
1answer
53 views

Output a symbol from Module or Block

I have troubles to output an entire symbol, a function in this case, from a module or a block. For instance myf = Block[{f}, f[3] = 33; f[4] = 4; f] Then I want ...
0
votes
2answers
124 views

Are there ways to create local variables analogous to a local variable in C++ and other languages? [closed]

There has been a great deal of discussion on local variables in Modules and Manipulate. If I am reading this correctly, local variables in a language such as C++ or C# are not exactly analogous to ...
1
vote
0answers
76 views

Building Reusable Custom Controls?

I would like to build an application using Mathematica 10. I would very much like to structure the application for maximum maintainability. To this end I would like to segregate controls and user ...
0
votes
1answer
90 views

Return a local variable from a Module containing a Manipulate

I would like to create a set of custom controls that call Manipulate[] and return the value(s) set during the Manipulate session. I can easily make a version that uses something like: ...
2
votes
1answer
154 views

Implementing local variables of a recursive function with either Module or Block

First, some quick background: I have been eagerly learning Wolfram and Mathematica for two months now, and along the way have written about 250 pages of teaching material that has ballooned into a ...
13
votes
1answer
307 views

Is garbage collection broken in version 10.0.0?

Bug introduced in 10.0.0 and fixed in 10.0.1 In version 10.0.0 under Windows I am observing the following behavior: ...
5
votes
3answers
148 views

Prevent iterator name from being confused with symbol passed into function body

I have a massive amount of code with lots of Table and Sum inside a Module. Each with their ...
2
votes
3answers
93 views

Dependency injection - use a specific implementation of one function within another

Consider... f[x_]:=Body containing h[some args]... g[x_]:=Body containing h[some args]... However I want to define something like... ...