Questions tagged [scoping]
Questions on Mathematica's scoping constructs (Block, Module, With, etc.)
566
questions
4
votes
3
answers
120
views
Evaluation control of nested With, If and Integrate
Can you explain the behaviour of the following?
The first With outputs unevaluated If.
So in the second ...
0
votes
0
answers
77
views
Red colored font in code
To avoid affecting lamda in other part of my notebook, I have wrapped code with Module. After wrapping, red colored font appeared.Could I know the reason?
...
9
votes
2
answers
494
views
What's the difference between With and ReplaceAll?
A wolfram Tutorial mentions that ReplaceAll and With are similar:
The way ...
3
votes
0
answers
49
views
Writing 'yield' style generator function
Just out of personal curiosity because I can't think of any solution. Probably, it's not possible, but I want a decisive answer. Is there some clever way of implementing the following function?
...
1
vote
1
answer
82
views
Define list of local variables to be parsed to Module
I have a Module which has $n$ local variables, say $a_i$. Now I want to write my Module in such a way that I do not need to change the code for varying $n$.
My approach is
...
1
vote
2
answers
82
views
SortBy does not work correctly when nest in Evaluate in With in Block
I have got some formula in Mathematica, then I want to pass value to verify them.
full code
...
4
votes
3
answers
147
views
With function replace rule does not work in
If I define an expression , and evaluate it in With function, replace rule does not work.
sumT = TA + TE;
With[
{TA = 0.1, TE = 0.2},
{TA + TE, sumT}
]
output
<...
0
votes
0
answers
55
views
Using a module that turns the output of Findroot into a function of a variable
I am trying to create a module that finds the root b* of some equation with two variables b and ...
0
votes
2
answers
67
views
Using Dynamic string output inside Block
Inside a Block, I have (among other things) a string output that is updated during an internal for loop in the following (schematic) way:
...
0
votes
1
answer
69
views
Using Manipulate for initial guess to nonlinear fitt, feed the result back to Manipulate (and repeat) for a general model with indexed parameters
I have been trying to put toghether a visual method to help fit experimental data with peaks. I have stumbled upon this answer which is very similar to where I got. But it is not sufficiently general ...
1
vote
2
answers
61
views
How to extract manipulated indexed variables from Manipulate
I am struggling with getting values of variables that are manipulated with Manipulate:
The code:
...
0
votes
0
answers
37
views
Manipulate with With and without - scope of variables
I am struggling with some basic concepts:
Why this works:
...
4
votes
0
answers
78
views
Temporary symbol leaks into public context?
This phenomenon has confused me a long time. Consider the following package example,
...
0
votes
0
answers
51
views
how to use subscripted variable such as a_i as the control of Manipulate?
I'd like to define a series of variables called $l_1$,$l_2$, etc., in Mathematica, using the "ctrl+_" shortcut. Moreover, I want to use these variables as the controls of a Manipulate[] ...
0
votes
0
answers
86
views
Interactive control panel using dynamic is surprisingly slow
I am hoping to create a user interface for performing gaussian fits on two dimensional data. I made a basic grid of various controls and labels. The tool works, but it's much slower than I anticipated,...
1
vote
1
answer
79
views
Dynamic text input of equation for graphing
I'd like a simple interface where the user can input (by text) a function $f(x)$, and then the function, its even part, and its odd part are all plotted on the same axes. I'd also like PlotLegend to ...
0
votes
1
answer
51
views
How to make this bisection code work for different equations?
I am very new to Mathematica. I have this code of Bisection Method for finding a root of a polynomial.
...
2
votes
0
answers
68
views
Most efficient way to define several local constants in a function -- Block or nested Withs?
Sorry if this is kind of a noob question but I'm wondering what the best-performing approach is to the following: I'd like to define several local constants in the body of a function, each of which ...
2
votes
0
answers
78
views
With[{a=1},{b=a},b] in 13.2 does evaluate to 1 [duplicate]
This isn't documented, and the front end highlights the second comma and third argument in red, but it's used in DownValues[Once][[3]] and is very convenient. Anyone know more?
1
vote
1
answer
52
views
Function definition inside Module with local symbol
Usually if I want to define a function using an expression I do:
expr=x^2;
f[x_]=expr;
which usually works and give f a defination.
But now if I want to do the ...
4
votes
1
answer
97
views
Passing control values out of nested Manipulates
I am building a "batch photo cropper" UI.
I have a list of images to crop, and I can use Manipulate to make a nice cropping UI for each one:
...
5
votes
1
answer
423
views
Is this buggy behavoir of Module solved? [closed]
I have just found out about this bug of Module, i.e. the creation of "zombie"-variables in some cases (see also this post).
I couldn't find a post saying ...
1
vote
1
answer
82
views
how to achieve “for(int i,i<=3,i++){}” of C++ in Mathematica [closed]
when i use Mathematica to do some small programmings, i always need to pay attention to variables-namings, i just wonder is there a way to achieve “for(int i,i<=3,i++){}” of C++ in Mathematica.
...
1
vote
1
answer
116
views
How to convert a function with named arguments to a pure function?
A function is defined with named arguments. How can this function be converted to a pure function that uses slots (#). As a simple example, how can the following:
<...
0
votes
1
answer
68
views
Problem with functions defined in Module in mathematica package
Might be very naive; I am trying for the first time to develop a Mathematica package as shown below. The intended usage is that the user will load the package, specify the input functions 'Model' and '...
2
votes
1
answer
88
views
Finding the output of the nested CompoundExpression
I am trying to catch the output expression of a nested CompoundExpression like this
...
2
votes
0
answers
144
views
What is the usage of other "*Block" and "With*"? [closed]
There exist some "kernel functions" that are related to the built-in scoping constructs: Assumptions`AssumptionsBlock, ...
13
votes
3
answers
486
views
Why does Module slow down StringMatchQ by 180 times?
I knew that Module is slower than With or Block, often by several times. But it surprises me ...
1
vote
1
answer
59
views
Variable replacement not working in ParallelTable
The following code produces different results using Table and ParallelTable. K and ...
1
vote
2
answers
102
views
Module returning Null even with Module as a Return parameter
I'm currently trying to implement Newton's method of approximating roots to approximate the root of 2. I looked into some possible reasons as to why it would return Null, such as the scope of the ...
5
votes
3
answers
303
views
How can I replace the locally defined function inside If with its value?
Consider the following module:
...
2
votes
1
answer
101
views
Dealing with locally defined functions in Module while exporting/importing
Consider the following example module:
...
2
votes
2
answers
204
views
about Return value of Module[]
questions are in the below code.
Although I'm pretty sure of the answer, I still feel a little uncomfortable, because I feel that the format of the body of Module[] ...
1
vote
3
answers
81
views
Local variables in a module don't show their actual values
I need to do the following transformation that
pick[a,b] -> ex[c|->{c[a],c[b]}]
ex is a function that accepts a function as parameter which returns a list ...
4
votes
1
answer
71
views
problem using package to verify solution of ode with Association, Naming scope/context handling [duplicate]
I learning how to use packages. I found a big problem. Here is description of the problem is, then a MWE is given.
This small package takes in an ode and ...
2
votes
4
answers
88
views
Always the same function in function table
Let's say, we have a list of points such as
Points = {{0, 0}, {0, 1}, {1, 1}, {1, 0}, {0, 0}};
This is nothing but the corners of a square.
List Plot:
Now I ...
0
votes
0
answers
91
views
Map-ed programmatic Style-s (based on user-input) are not evaluating. Scoping constructs are suspected
The top function manages several sub-functions which set visual properties over a list of Options.
Inside stylerules the ...
0
votes
0
answers
50
views
Efficiency in a use of ParallelMap[]
Suppose M is a large and relatively dense symbolic matrix. I am interested in applying F[] (...
5
votes
1
answer
88
views
Automatic scoping of input to function
I'd like to write a function whose arguments contains symbols that are automatically localized, just like some built-in functions, like Sum. Even better, I'd like to see the symbols' color change, to ...
3
votes
1
answer
88
views
Antiderivative of a piecewise function evaluates wrong inside a subroutine
It's very helpfull to use antiderivative of a given function in the form Derivative[-1][fun][t]!
Here my example with a simple piecewise function:
...
0
votes
1
answer
53
views
How to use Assuming and With together
(I am sorry for the ASCII form, I use the free WolframEngine which works in text mode.)
I have these assumptions ...
1
vote
2
answers
111
views
Symbolic manipulations of predefined variables without numerical substitution
As a novice in Mathematica I would like to expand an expression without substituting its variables so that
x = 4; y = 4;
Expand[(x^2 + y^2)/x^2]
generates the same ...
0
votes
0
answers
44
views
How do I build a module that takes in graph data? [duplicate]
This is a homework problem I'm really struggling with. I'm supposed to program the shortest path problem in Mathematica. There are 100 nodes, each node has corresponding distances to 2-3 more nodes. ...
4
votes
0
answers
77
views
Condition-in-scope as a rule for SequenceReplace
Bug persisting through 13.1.0 [CASE:4841653]
From
...
2
votes
1
answer
280
views
How to assign a value to something inside a module globally? [closed]
Let's say I created a function that calculates something inside a module. How do I assign that result to a global value?
Let's say I have this:
...
6
votes
2
answers
1k
views
Unexpected result with sums in set delayed functions
I don't know if I've just found a bug (and if so, whether there's a workaround), or if I'm just losing my mind. Without further ado, here is my code (really, a minimal working example), run on ...
1
vote
0
answers
28
views
Sequential vs Nested Module for closing tagged cell
I have the following simple line of code in my notebook
Plot[x^2, {x, 0, 2}]
I add a CellTag with the string "Plot" to that cell.
Sequential Module
I ...
1
vote
2
answers
170
views
Problem regarding "With" function
I am trying to calculate the effective potential using this code in Mathematica:
...
1
vote
0
answers
65
views
Is it safe to name the local variables by ending with "$"?
In many cases I need to copy the Global` symbols foo into Module/Block, and to memory the ...
0
votes
0
answers
29
views
Set keeps RHS unevaluated when RHS is a Module variable [duplicate]
Consider the simple code
...