All Questions
Tagged with scoping list-manipulation
25 questions
1
vote
2
answers
72
views
How to extract manipulated indexed variables from Manipulate
I am struggling with getting values of variables that are manipulated with Manipulate:
The code:
...
- 4,036
1
vote
1
answer
63
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Variable replacement not working in ParallelTable
The following code produces different results using Table and ParallelTable. K and ...
- 37.4k
0
votes
0
answers
165
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Using the for loop in the Module function
Good afternoon, I need some help. I have compiled a function that calculates the flight of the ball, step by step I made an analytical solution first, then a numerical one. But in numerical it is not ...
- 101
2
votes
1
answer
47
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Why are the inputs not being applied to the function in this MWE?
Consider the following MWE
...
- 56.4k
9
votes
1
answer
156
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How to define a version of Table[] which localizes iteration variable by Module[]?
For reusable code it's good practice to use Module[] to localize iteration variables used by Table[], as explained by this post.
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- 115k
3
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2
answers
2k
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Can you unpack a list of values into variables in a With expression?
For instance, if I am trying to draw a graph with 5 vertices labeled a through e, and I want to draw edges connecting a and b, a and c, a and d, a and e, b and c, b and d, and c and e, I would run the ...
- 551
2
votes
1
answer
136
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How to partition $[0,1]$ into $m$ equal sub-intervals and count the number of sub-intervals that intersect with my cantor set?
Suppose I define my cantor set as
...
- 121
9
votes
1
answer
394
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Local variables in sums and tables - best practices?
Stumbled on Local variables when defining function in Mathematica in math.SE and decided to ask it here. Apologies if it is a duplicate - the only really relevant question with a detailed answer I ...
- 69.3k
1
vote
1
answer
63
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How to set same Variables with different Values [closed]
I have a pipe with different insulation sections and a fluid flowing through. I need to calculate the fluid Temperature at the end of every section, to estimate the temperature for the next section. I ...
- 108k
0
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1
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109
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How to use module to assign functions to a set of imported text files?
I have a lot of text files in my folder (in this example I'm using only 8). I am trying to import all of them and then do calculation on each individual file; I want to use the same notebook without ...
- 10.4k
1
vote
2
answers
268
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function fails to use local variable when it is called inside a Module
I have these two functions fun and microstep.Fun makes use of a Module construct within which I define the ...
- 543
2
votes
2
answers
293
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Table and evaluation order
I thought Table should not evaluate the inner code until it inserts the value. I'm confused by
test1[3]="a";
test2[4]="b";
Table[DownValues[i],{i,{test1,test2}}]
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- 4,781
2
votes
1
answer
1k
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A function which performs multiple steps
I'm trying to figure out how I can define a function which takes an input, performs an operation on it, then produces a table from the result. For example, I have a function ...
0
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1
answer
59
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Error when calculating more than 1 input
I'm trying to solve a problem where I can't do more than 1 calculation inside a Module here. I have a list of numbers where ...
- 23
4
votes
1
answer
135
views
Using Position[] inside a Module
I have a dataset with missing or wrong values. A module should replace those values so that the dataset length is preserved. For identifying the positions to be replaced I use ...
- 138k
1
vote
1
answer
282
views
0
votes
0
answers
71
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Error in storing the output of a module (subroutine) into an array
For a physics application, I have to compute components of a rank-4 tensor, the Riemann tensor. I do this using a module (subroutine) which looks like this
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- 411
0
votes
2
answers
422
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Using recursion to find the trace of gamma matrices
All you need to know about the gamma matrices for this problem is that there are four of them, $\gamma_{\mu}$ with $\mu = 0, 1, 2, 3$, and that the trace of the product of n gamma matrices (n even) ...
CommunityBot
- 1
2
votes
0
answers
136
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How does Table behave differently? [closed]
I have some functions, that I cannot break down to a reasonable MWE, so I'm going to try for an abstract question without providing the code. If need be, I'll include the extra code.
I have some ...
- 27.6k
11
votes
2
answers
264
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How to correctly implement in a new function the scoping behavior of Table, Sum and other commands that use Block to localize iterators?
It is documented that "Block is automatically used to localize values of iterators in iteration constructs such as Do, Sum, and Table." Therefore the dummy index (iterator) in a Sum is shielded ...
- 588
1
vote
3
answers
147
views
1
vote
1
answer
1k
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Change input variable in a function [duplicate]
I'd like to write a function, that would take a matrix as an input parameter and would change it by multiplying one of its rows by a factor.
I try to do it in the following way:
...
- 198
1
vote
2
answers
246
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`Slot` (#) interfering with evaluation
In the following I am using one function makeFunc to assemble two functions a[t] and b[t] to ...
CommunityBot
- 1
0
votes
1
answer
866
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Passing lists to functions in a manner that works like pass-by-reference in other languages?
Is it possible to use a list as a variable, i.e., to pass it by reference to a function?
In particular, I have a two-dimensional array and a function to get one element specified by its position:
<...
CommunityBot
- 1
9
votes
3
answers
888
views
How do I avoid scoping collisions of iterator variables?
Yesterday I had an issue that kept for quite a while. My code wasn't producing the right results. Now I know why and I am wondering how to avoid the issue in future. Consider the following code.
<...
- 4,751