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

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7
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1answer
279 views

Variable scoping in Module

I don't understand why $a$ and $b$ are not local in the following code: ...
7
votes
1answer
272 views

Module variable scoping in Scheduled Tasks?

I ran across a scoping puzzle while experimenting with ScheduledTasks, and I'd be grateful for an explanation from the sages here. I found a workaround by intuitive horse sense, but was unable to ...
7
votes
1answer
161 views

How to inherit options by scoping?

Consider the following example: you have a function framed producing a cell with a button that, when pushed, calls framed again. ...
7
votes
1answer
79 views

How to reset the $ModuleNumber?

According to the documentation, we can reset $ModuleNumber to a positive machine integer. There is even an example in the doc: ...
7
votes
1answer
230 views

FullDefinition and Module local variable

I have a question about FullDefinition and how it interacts with the local variables of Module. I've created a few functions ...
7
votes
1answer
220 views

Difficulty catching thrown errors in asynchronous tasks

In this Question, Leonid explained that module variables can get garbage collected from a chain of asynchronous tasks unless their Temporary attribute is cleared ...
6
votes
1answer
3k views

Module with “local functions”

I am trying to use a Module having "local functions", i.e., those which I need to define only inside this module. So I tried this: ...
6
votes
1answer
291 views

A smarter nested With?

I often find myself writing code that looks a bit like this: ...
6
votes
2answers
253 views

Variable scoping problem when mapping over delayed replacement

This is something that got me curious while I was playing around with Mathematica. Consider the following (contrived) example: ...
6
votes
1answer
192 views

Creating a Block from a list of rules

How can I create a function which works like Block but takes a list of rules as its first argument, rather than a list of assignments? The function needs to be ...
5
votes
4answers
286 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 ...
5
votes
3answers
291 views

Notation for specifying transformation rules

I would like to have a compact notation for specifying conditions and results in transformation rules. Consider ReplaceAll: ...
5
votes
3answers
164 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 ...
5
votes
1answer
239 views

Parts of Module body evaluated in external scope?

I have an expression that suggests that some expressions in a module body are dragging in definitions from outside the scope in a surprising way. First, consider a symbolic constant, ...
5
votes
2answers
211 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 ...
5
votes
2answers
154 views

Generating EventHandler using Table

I would like to change the edge color of a graph when double clicking on it, the following code works: ...
5
votes
2answers
143 views

Checkbox behaving weird when variables are local

I have a DynamicModule in which I need a checkbox with a Max in the dynamic part: ...
5
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3answers
201 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 ...
5
votes
1answer
102 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. ...
5
votes
1answer
93 views

Dynamics and Block interfere

As mentioned by Albert Retey in a comment, we can unintentionally interfere with our dynamics as follows ...
5
votes
1answer
63 views

How to solve an equation system whose equations are based on Mod[x,y]

I'm trying to find the parameters of a specific linear congruential generator (pseudo random number generator) based on a list of the first five numbers generated by it. The list is this one: ...
5
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0answers
211 views

Exhaustive examples of variable replacement due to nested scoping constructs

Consider the following examples, where I have replaced dollar signs in the output by a D. ...
5
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0answers
126 views

Are there any videos that show how different Mathematica expressions are evaluated?

Are there any videos that show how different Mathematica expressions are represented internally as object graphs and demonstrate how they are transformed during an evaluation? I am asking because I ...
4
votes
3answers
694 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 ...
4
votes
2answers
97 views

How can I pass arguments to Module without being reinterpreted each time they appear inside it?

I'm trying to understand how to save time when calling functions in Mathematica. I wrote this example, ...
4
votes
3answers
99 views

Creating a function after working out an example calculation

I have created this setup, it is giving me the correct answer, however I am interested in a function that does all this calculations and creates a output of mean and standard deviation. The function ...
4
votes
2answers
296 views

Comparing LetL and Module efficiency

I was recently introduced to the LetL macro thanks to Leonid's answer to one of my prior questions. I was, needless to say, impressed by the simplicity of its ...
4
votes
2answers
578 views

Local variables

I'm trying to use Modules together with functions. tmp2 = x^2 + 1; f[y_] := Module[{x = 1}, Evaluate[y tmp2]] This works when ...
4
votes
2answers
118 views

How to take derivative of a interpolated function inside the module

When handling derivatives of a interpolated function, I often use the following function makeDeriv[f_InterpolatingFunction] = D[ f[x], x] Then, I can define ...
4
votes
3answers
278 views

Modify this code using Module and While

I have written a recursive function and would like to re-write the code using Module AND While to compare the timings. Here is my recursive function for f[n], where 6 n f[n] = f[n-1] + n! for n>0 and ...
4
votes
1answer
246 views

How to avoid conflicts between local variable names and symbolic arguments in Block constructs?

I am using Block inside the definition of some recursive functions. If the Block definitions use short variable names, like ...
4
votes
1answer
108 views

Unwanted interaction between instances of a Manipulate function

The function trajectory below is defined in terms of Manipulate and calls the auxiliary function ...
4
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3answers
244 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: ...
4
votes
2answers
172 views

TrackedSymbols affected by CurrentValue. Another problem with SetDelayed(:=)+OwnVales in Initialization

It is MWE, only a Disk[] that should print "Click" when clicked. Also "date... updating" ...
4
votes
1answer
126 views

Dial control for Manipulate?

I'm trying to make a control item in a Manipulate that is a simple dial. I'm trying to mimic Manipulate[theta, {theta, 0, 360}], ...
4
votes
1answer
165 views

Downvalues vs. Scoping for Functions

Regarding my recent question on using a default value for a function argument when a pattern was not met yielded some interesting answers, but the general consensus was "Yes this can be done, but ...
4
votes
2answers
73 views

Assigning function values in a memoized recursive module

I have a complicated recursive module which I have memoized. I realised that certain isomorphs of inputs to this function will give the same output. Therefore I decided to memoize all such ...
4
votes
1answer
252 views

Namespaces in Mathematica

In many programming languages one can define a namespace with namespace abc How can the similar be done in Mathematica? The ...
4
votes
1answer
149 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 ...
4
votes
0answers
275 views

Module in numerical model for NonlinearModelFit is slow and leaks memory

I am trying to make a NonlinearModelFit where the model is the result of a numerical calculation. My code works, but it is very slow and also seems to have a memory ...
3
votes
2answers
108 views

Is there a way to localize Off[some::message]?

Is there a way to temporarily suppress certain messages, so that I could write for example (with made-up syntax for that feature): ...
3
votes
1answer
163 views

Issue with scope of variables

For the definitions, t = 1; f[x_, y_] := t (x + y); v[3] := {1, 1}; g[u_] := f[v[u][[1]], v[u][[2]]]; the following two expressions yield different results, ...
3
votes
3answers
112 views

Name scope confusion

Sorry for the too ambiguous title. First consider a following code snippet. ...
3
votes
2answers
391 views

How to declare a function that uses local variables of a module outside this module?

I have the following code Module[{f,x=0}, f[t_] := x + t; ..........; ...f[1]...; ..........; ] My aim is to put the declaration of the function ...
3
votes
2answers
91 views

Module, local variable

Lets say I define a Module, that internally use iterating in a Table or Do, say something ...
3
votes
2answers
105 views

Sections with unidirectionally shared variables

I have 2 sections is my notebook: ...
3
votes
2answers
370 views

Why does the syntax highlighter color a local symbol red inside DynamicModule?

I am adding a Module inside DynamicModule here is an example (thanks to @rm-rf for this simple example) ...
3
votes
2answers
120 views

Plotting a function variable vs. an explicit function

Can someone tell me why this doesn't plot/animate? ...
3
votes
1answer
50 views

Blocking Dataset`$ElisionThreshold doesn't work

I would like to define a simple function to automatically show all rows in a Dataset. Based on Taliesin Beynon's answer, I tried the following trivial snippet: ...
3
votes
1answer
307 views

Call Functions From File Without Modifying Context (Sandbox)

Let's say I have file named test.m containing test[arg1_] := ( Print[arg1];) What is the best technique for calling test like ...