All Questions
589 questions
3
votes
1
answer
131
views
function evaluation - I don't get it
this function returns Pi/4 for a[1,4]
In[...]:= a[r_, n_] :=
Module[{an = Pi/n, h = r Cos[an], w = 2 r Sin[an]}, an];
a[1, 4]
Out[...]= Pi/4
so the kernel ...
- 487
5
votes
1
answer
131
views
why DSolve in V 12 returned an internal module variables with $ on them in this example?
Fyi, Reported to WRI in case it is a bug. [CASE:4288939]
Is this supposed to happen?
...
- 150k
1
vote
1
answer
155
views
How to use Module function?
Here is my issue; I want to iterate a fit to this data for a polynomial of degree 2 up till degree 6. However, at each iteration I drop certain data points that have a poor residual value. So each ...
0
votes
1
answer
111
views
Modifying/optimizing a double sum with an If condition
I would like to better understand double summations where one of the sums depends on the upper limit of the previous sum. This appears frequently in representation theory (to the extent of my ...
user49048
1
vote
1
answer
62
views
Variables referring to other variables within Module
The following doesn't work:
Lol[x_, y_] = Module[ {w=x+1, z = w + 1}, z]
because z refers to ...
- 3,175
1
vote
1
answer
148
views
Using rules inside Module or Block
I have a rather long piece of code inside a Module, and I want to provide different parameters to the different pieces inside the ...
- 67
0
votes
1
answer
216
views
13
votes
4
answers
1k
views
What is the accessibility of a package's `Private` context variables?
I've been reading up on how Mathematica handles contexts, $Context, $ContextPath, and a few of the tutorials they have on ...
- 489
6
votes
1
answer
148
views
RegionPlot3D no longer localizes its arguments?
Bug introduced after 9, fixed in 12.0.
Just now, I was astonished to find the behavior of RegionPlot3D changes somewhere after v9 . Consider the following sample:
...
- 68.4k
3
votes
1
answer
343
views
How to trace value assigned to local variable(variables in Module)?
Bug introduced in v10.1 or earlier and persists through v11.3
CASE:4240757
Here is my code:
...
- 165
0
votes
0
answers
175
views
Assigning values to variables inside Module using user defined function
Say I'm defining a function
with some local variables, for which I'm using Module. Now, I want to assign some value (or perhaps a list of values or a list of list, ...
- 1,404
1
vote
1
answer
339
views
Why are there local variable conflicts in my recursive function definition?
Sorry to post a long piece of code. There are two places in here where I Print[] 'path2' when the count == 984, because for some reason, that list is getting ...
- 4,642
0
votes
1
answer
101
views
Different result in ContourPlot function using different version of Mathematica (?)
I tested "Elasticity with Mathematica" notebook (Mathematica 6) in Mathematica 11.3 and tested C05_stress_kirsch.nb, I added some trigger code to protected function in the tensor2analysis.m file, and ...
- 1
2
votes
0
answers
41
views
1
vote
0
answers
48
views
Why doesn't `ReplaceAll` work in this situation? [closed]
I can work around this by using With, but it seems really odd to get the following:
...
- 2,335
0
votes
1
answer
246
views
Multiple functions within a Module
I have a function that extracts a numerical value from two vectors, written as Spa[i_,j_]:=Flatten[LaU[i].LaD[j]][[1]]. (Note, I'm sure that this isn't the most ...
- 135
1
vote
0
answers
115
views
Function returned from module doesn't work [closed]
I have a sequence of steps that work in the main notebook:
...
- 343
3
votes
2
answers
338
views
Finding the inverse of a function
I am to solve for $r(\rho)$ given the function,
ρAsymp[r_, b_, q_] :=
1/(1 - q) Gamma[1/(1 - q)]/Gamma[(q - 2)/(q - 1)] r Sqrt[1 - (b/r)^(1 - q)]
This can be ...
- 181
1
vote
1
answer
49
views
Evaluation of Extract and use the result in a Sum
I am experiencing a problem in the evaluation of a sum. I hope that someone can help me, I am not an expert Mathematica programmer. I'm posting just the portion of code that gives problems, I know ...
- 11
4
votes
2
answers
279
views
Scoping of pattern variables [duplicate]
I have run into a problematic behavior, and then came to find that it is a "possible issue" called out in the documentation, but I guess I am just baffled that this IS an issue, and am wondering why. ...
- 2,307
0
votes
1
answer
159
views
Can I bake my own PI using your Wolfram language oven and prebuilt utensils? [closed]
How might I override the value of the Greek letter PI within various builtin language functions in the Wolfram language? Specifically and without having to reinvent the wheel or code equivalent ...
2
votes
1
answer
327
views
How to define a function inside a module through Evaluate [duplicate]
I am trying to define a function inside a module as following
...
- 1,473
0
votes
0
answers
48
views
Symbol created in Module not seen outside of Module scope [duplicate]
I am using a function defined with a Module[]. In the Module I am creating a new variable name using a ...
- 1
1
vote
0
answers
67
views
ConditionalExpression still resulting from Assuming a Module's local variables
I have a memoizing, recursive function whose MWE looks like this (the two fake inputs/ICs are from 'K' and 'Bfun2', the latter just a quick way to check the results coming out of the Residue.:
...
- 455
1
vote
2
answers
204
views
How do I localize changes to a variable inside a Do-loop?
I want to change the increment value inside the do loop . But i dont know why it remains for the first declared value?
...
- 203
3
votes
3
answers
159
views
MostOccuringWeekdays Wolfram Challenge [closed]
I am working this challenge from Wolfram Challenge. I believe that I have solved the problem with the following code (note it is not very efficient - I am new to Mathematica!)
...
- 477
3
votes
1
answer
132
views
Module - Symbols out of scope of lexical scoping
The Problem
Consider the following code (1):
In[1]:= x = 2;
Module[{x, y},
y[x_] = x;
y[1]
]
Out[2]= 2
I expected the answer ...
- 1,125
3
votes
3
answers
240
views
What is wrong with Module? or me? [closed]
The following code does not give me an answer. It looks all is working when each command inside Module is individually run. But ...
- 6,409
2
votes
1
answer
146
views
Why does Mathematica stay on an endless evaluating loop with Manipulate?
I have built Manipulate to see the impact of a change in time and volatility to the profit of an option strategy, bull spread.
To calculate the price of the option, I built the good old Black-Scholes:
...
5
votes
1
answer
179
views
With vs. Block scoping of parameters for Plot
A very basic question..
Why does Block work, but not With, to specify value of a parameter for a function to be plotted?
...
- 12.1k
5
votes
2
answers
207
views
HoldAll Attributes and Delayed Evaluation: ContourPlot with solutions to NDSolve
This is a general question on evaluating functions that are defined to be evaluated with delay.
In particular, I am having difficulties working with the ...
- 607
1
vote
3
answers
158
views
Prime number counting function
As part of an assignment for a calculus class, I have to write code for the prime number counting function $p(n)$, I have no problem creating the function itself, but for I want it as a function, ...
- 23
6
votes
0
answers
67
views
Nested rules and automatic renaming of variables [duplicate]
I understand why $ happens here:
ClearAll[foo]
foo[a_] := (x_ :> a x)
foo[1]
...
- 138k
1
vote
0
answers
62
views
What use is empty binding list in `Block[{},...]`? [duplicate]
Spelunking the Export function, I stumbled upon the following definition:
...
- 794
2
votes
1
answer
128
views
1
vote
1
answer
87
views
Problem passing argument in hash table from global context to a module
I was experimenting with passing arguments via a hash table to a module. Found a very strange result. When I pass a function to be plotted inside the module, it comes out empty.
Yet all argument ...
- 150k
3
votes
1
answer
246
views
Module and With do not work in some cases
I apologize if the title is too vague/general but I couldn't find a better one. I am trying to use either Module or With but it does not work if the object containing the local variables is defined ...
- 297
9
votes
0
answers
191
views
A bug in Derivative?
Update
This is a bug in v11.3 or earlier and is fixed in v12.
Original Post
Check this out:
...
- 2,814
0
votes
1
answer
159
views
Want help with debugging a For-loop
I'm trying to run a simulation, which at the end gives a value 'qber'. Now I want to run this simulation multiple times with different values of 'p' each time. And these value of 'p' are actually the ...
- 35
2
votes
2
answers
837
views
Clear variables inside Module
I have a function that uses Module. The function takes as input a .csv that can have as many columns as it wishes to, and it ...
- 425
6
votes
4
answers
229
views
Create rule whose LHS is already defined
My question will be clearest if defined using an example. Consider the following code:
Func[k_]:=Block[{a},
a[t_]:=t^k;
{a[t]->a[t]}
];
However, calling ...
- 295
1
vote
0
answers
59
views
Dependent variables in With operator [duplicate]
I want write something like this
With[{x=1, y=x+1}, y]
and get 2 as an answer. What is the correct way to do this?
- 535
0
votes
0
answers
185
views
How to speed up a module function with a large number of arguments?
I'm setting up a fairly hefty numerical code dealing with matrices
of variable dimension, but on the order of hundreds of rows and columns.
I'm using a Module format:
...
- 58
1
vote
2
answers
268
views
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 ...
- 2,709
0
votes
0
answers
45
views
0
votes
0
answers
37
views
How to define a global function dependent on a local pattern? [duplicate]
When g is in the local scope defined by Block, the following fails:
...
- 4,225
2
votes
2
answers
293
views
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}}]
...
- 4,781
1
vote
1
answer
49
views
Manipulating definitions while reading them with Get
In order to read in a definition with certain parameters replaced by appropriate values I can use for example
Block[{a=1.1,b=2.2}, Get["file"]]
where ...
- 4,781
2
votes
3
answers
738
views
Use of Module With Functions
Really confused by how one should use the Module[] command in two variables. For example my function here should return the ...
- 21
0
votes
0
answers
43
views
Tracking System function (Get) calls, and Stack[_]
Consider the following attempt and variations thereof to track (nested) calls to Get (reasoning of this approach below):
...
- 34.4k