Questions on the basic structure of the Mathematica language (Wolfram language) including atomic data types, syntax etc

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0
votes
1answer
52 views

How to destructure local variables?

Why can't I use this Where[{iw, ih} = ImageDimensions[i], ...] instead of this ...
0
votes
1answer
63 views

Permanently fixing a variable in the function

I need to define a function let's say f[x_, y_] := x^2 + y^2 such that I need to fix one variable (let's take y = a) and to ...
0
votes
2answers
78 views

Function that creates a table from two lists

I have two lists shown below: list1 = {(0,0,0,0),(0,0,0,1),(0,0,1,0),...,(1,1,1,1)} list2 = {1,5,5,5,...,5} How can I construct a function that outputs a table similar to this: $$\begin{array}{c|c} ...
0
votes
2answers
158 views

How to construct a linear feedback shift register

Are there any posts regarding the construction of a LFSR (Linear Feedback Shift Register) in Mathematica? I can't seem to find any and I am not sure how I would construct one.
0
votes
1answer
64 views

Built in function to convert list of numbers into list of binary numbers [closed]

Does Mathematica have a build in way to convert a list of numbers into a list of binary numbers? If not how can this be accomplished?
0
votes
1answer
127 views

Help with functions in Mathematica

I'd like to make a function that has many parts. Doing this in something such as Java, which I am familiar with, would be simple. In Mathematica I have these "pieces", which I want to put into a ...
2
votes
5answers
229 views

Making loop based off what I can say in words

I have a list of values a: {1,4,11,14} I want to print out values that satisfy b(1+a) = 0 mod 15 where b are the values from 0 to 14. The output I am wanting is ...
2
votes
3answers
84 views

Perform For-loop and show output which meets a certain criterion

I am new to Mathematica and I have a For loop like so: For[i = 0, i < 15, i++, PowerMod[i, -1, 15]] Currently it doesn't output anything. The calculation I am ...
0
votes
0answers
31 views

How can I remove some bad rules applied as a result of syntax error?

This user is pretty light-weight regarding Mathematica rules and such. I dont know how the following issue was created (some prevous bad syntax in the same session) ...
10
votes
1answer
374 views

How to visualize pattern matching process?

I want a function that does the same job like ReplaceRepeated, and can make the matching process visible. I searched the Internet but didn't find any existing code ...
1
vote
1answer
125 views

Using FindMinimum with matrix input

I define the following function which spits out a number S when I feed it a dxd square matrix: ...
0
votes
0answers
57 views

Using NestList instead of Do [duplicate]

How can I express the following code using NestList: ...
10
votes
1answer
174 views

Copy Built-in function to new name

It is know that some built-in functions are system function and changing their properties may cause trouble. Suppose for example I want to change features of Cases: ...
4
votes
3answers
254 views

Manipulate: How to create custom reset Button automatically?

I have a complex Manipulate with more than 10 controls. Each one has its own default value. I'd like to add a custom button in the control area to reset all ...
14
votes
2answers
450 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 ...
17
votes
1answer
386 views

Confused about how Partition works

I have a problem about the padding list about Partition command. For instance, ...
4
votes
1answer
128 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 ...
0
votes
1answer
308 views

How do I write nested for-loops?

Looking through the reference.wolfram, I couldn't see an example of how to write a multiple line "for" loop in Mathematica. I need to nest many for-loops in such a way I can do many things in the ...
5
votes
2answers
405 views

Code elegance and compactness. Help needed with Map, Apply

I need some help with code optimization and compactness. I have a set of two-dimensional points and I can use the Mathematica function FindClusters to find 4 clusters. I'd like to plot the points ...
2
votes
0answers
67 views

What was the thought behind the parallel versions of Table, Map, etc..?

There separately named versions of the parallel analogues of Map[] and friends: ...
1
vote
1answer
87 views

Computing a Sequence using Recurrence

I posted a similar question earlier today, but unfortunately I realized after several hours that I over-simplified the problem for this forum. There is a very good answer to the Computing a sequence ...
2
votes
3answers
122 views

Computing a sequence by recurrence

I am trying to create a list where each element of the list is calculated using the sum of all previous elements of the list and also uses the $N$th element of another list. The initial value of the ...
21
votes
3answers
552 views

Real Numbers in the Wolfram Language

Epilog: Much of the discussion in the answers below revolves around the distinction between Real as a data type and real numbers as a domain or class of numbers (irrespective of the form in which ...
2
votes
2answers
103 views

DictionaryLoopkup - pattern specification

I would like to find all Italian words that have a specific pattern of letter repetitions. Actually I'm looking for 6-letters words that have 1 letter repeated 3 times, a second letter repeated two ...
3
votes
1answer
214 views

How can I trans-compile Mathematica into another language?

I'm looking for an exhaustive list of source-to-source compilers to all other languages, if any exist that is.
5
votes
1answer
104 views

Changing the definition of N: unexpected $RecursionLimit::reclim error

I have some objects represented as follows: Object[data, param] data is a list of numbers, ...
14
votes
3answers
215 views

How do I understand ListCorrelate(contains $\{k_L,k_R\}$) when it works for 2-dimentional data?

Two months ago, I asked a question here And @nikie give me a solution: The intuitive way to understand ListCorrelate is that the kernel is "moved" to every ...
4
votes
1answer
41 views

How to find out which definitions use Temporary symbol?

According to the Documentation, Symbols with attribute Temporary are automatically removed when they are no longer needed. For example: ...
1
vote
0answers
74 views

Concise way to express Table[FactorInteger[300][[n, 2]], {n, 1, Length @ FactorInteger[300]}] [closed]

I can get the exponent part of FactorInteger[300] with Table[FactorInteger[300][[n, 2]], {n, 1, Length @ FactorInteger[300]}] ...
20
votes
1answer
364 views

Why some built-in functions are slow

I just wonder why some built-in functions are slower compared to some other ways using more than one built-in functions for doing same job. consider this example: ...
3
votes
2answers
103 views

MapThread problem

I would like to do the following: ...
4
votes
0answers
85 views

Unexpected behavior from Indexed

I was going to include Indexed in this answer, thinking that it operated much as a List-only ...
0
votes
1answer
65 views

What does this Append expression do? [closed]

I have to understand some code. A part of it is written below. Can someone explain to me what it does: ...
9
votes
2answers
126 views

DownValue assignment using Apply

Why does assigning a DownValue using Apply, e.g., ...
9
votes
6answers
378 views

Product of elements of a list

Sum is for functions; Total is for a list. Product is for a function; what is the command ...
2
votes
0answers
31 views

How exactly does ReplaceAll work? [duplicate]

I am not sure if this question has been asked before but anyway, Consider these two examples: ...
0
votes
0answers
96 views

Solution of a set of quadratic congruences (Chinese remainder)

Edit: Please remove this question. I think there are mathematics error in what I am asking. You are welcome to edit the question if you can state the problem correctly. I have a set of quadratic ...
5
votes
4answers
210 views

Signed power set of a list

Given {a, b, c, ...} with $n$ elements generate a list with $2^n$ elements. For example, if the list were {a, b, c}, then the ...
5
votes
2answers
152 views

Non sequitur in documentation of MemberQ

Mr.Wizard's question about MemberQ and FreeQ got me to re-read the documentation for those functions. I find I don't understand ...
16
votes
1answer
181 views

A bug in the overloading of MemberQ and FreeQ for Association?

Bug introduced in 10.0.0 and fixed in 10.1.0. While answering Pattern match for nested Association I came across behavior of MemberQ and ...
0
votes
1answer
81 views

Association of pure functions [duplicate]

I've encountered confusing behavior of Association when I try to use it for storing pure functions. For example: as = <|"1" -> # + 1 &|> ...
10
votes
5answers
595 views

Postfix Double Slash Notation with Multiple Parameters [duplicate]

Examples A convenient shorthand that I use frequently is the "double slash" notation to string commands together. For example, I can write: ...
2
votes
1answer
324 views

Dynamic graph construction and visualization (Watts' “Small Worlds” α-model)

I need some help in creating a Mathematica program for building and visualizing Watts' "Small Worlds" α-model. This is a variant of the more known (and much more simple) β-model (also known as ...
12
votes
2answers
256 views

How to restore function attributes to default

Adding an attribute to a function is easy and clearing attribute is easy also. But I don't know really how to restore the attributes of a function to its defaults. All I do is quit the kernel or close ...
3
votes
1answer
326 views

How to use Mathematica for traditional programming

I am new to the structure of Mathematica. I understand that in the notebooks, one enters the symbolic expressions and evaluates them. But I need to generate some simulated data and do that a few ...
7
votes
1answer
215 views

Why can't a string be formed by head String?

Since everything is an expression in Mathematica, why must a string object be formed by "abc" but not by a String[abc] ...
2
votes
3answers
192 views

How to test for Indeterminate values?

I need something like this a = 101010/0; If[a == ComplexInfinity, True, False] But if I use ToString, I get what I want. ...
6
votes
1answer
208 views

Taking the derivative of a function with indexed variables

I have a number of functions that depend on a variable x. I am using a second, integer variable to index these functions, i.e. something like ...
1
vote
1answer
47 views

Strange behaviour of Set and Part when given a sequence

Consider this example: lis1 = {a, b, c}; lis1[[2]] = Sequence[e, f]; lis1 (*{a, e, f, c}*) lis1[[2]] (*e*) lis1[[2]] = Sequence[g, h]; lis1 (*{a, g, h, c}*) It ...