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2
votes
1answer
48 views

Expressing a definite integral as pure function with the upper-bound as it argument

Suppose i have an integral which has a closed form, $\quad \quad \int_{a}^{b} f(x) dx=F(a,b)$ I want to use output function $F$ as a pure function, like ...
1
vote
2answers
47 views

Perform operation on part of a table / create a reference

There is a function f that I would like to operate on a rectangular part of a table t. The part is specified by function ...
0
votes
1answer
50 views

Suppressing tiny imaginary parts in complex numbers [closed]

How do I extract the real part of a substitution expression from FindRoot or Solve? Or alternately, how do I insist that they ...
41
votes
1answer
922 views

Incompatible Changes since Mathematica Version 7?

There is documentation of the incompatible changes made to Mathematica with each major release: Incompatible Changes since Mathematica Version 1 Unfortunately that documentation simply stopped ...
0
votes
1answer
65 views

Create an array with certain conditions and use it to fill a matrix [closed]

I am translating my code from Python to Mathematica. Here is a piece of my Python code: ...
1
vote
1answer
68 views

Defining a function of matrices [closed]

I am translating my code from Python to Mathematica. How can I define a function similar to the following: ...
0
votes
0answers
37 views

Substitution Permutation Network (SPN) - Decryption In Mathematica

I am working with a Substitution Permutation Function, SPN, in Mathematica. I have an encryption function for an SPN. By changing the parameters that go into the spn function, and not the function ...
3
votes
3answers
138 views

Pick bug? level 0 matching

A previous discussion of this issue (Is there a bug in Pick?) accepted that matching at level 0 is not a bug in Pick. Was that correct? I am not yet persuaded. ...
2
votes
0answers
52 views

Minimalistic code challenge on Apollonian gaskets

I've been recently fascinated by the beauty, symmetry and mathematical richness of the Apollonian gaskets. So I felt myself challenged to see if it was possible to generate one in Mathematica with ...
16
votes
0answers
158 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 ...
2
votes
2answers
142 views

Issue with Set function

Tables often come with column headers. Indexing the columns with the header is a natural thing to do. Although a proper dictionary is the usual solution in such a case, I find it often practical and ...
2
votes
3answers
61 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
1answer
34 views

Generating comma separated input for LCM [duplicate]

I would like to calculate the Least Common Multiple of the 100 first numbers. I've tried with LCM[Table[i, {i, 10}]] But it produces a list instead of the right ...
3
votes
0answers
89 views

Mixing Wolfram Language & WolframAlpha Queries - How robust is it?

The advent of Mathematica in the cloud and linguistic input potentially transforms expectations of the Wolfram Language's programming model and its inherent robustness. An example of this comes form ...
7
votes
1answer
87 views

Context-dependent functions

TL;DR warning! My question is not about getting the length of the ticks correct (although if someone has good suggestions, that would be welcomed). My question is about constructing functions that ...
17
votes
1answer
301 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: ...
13
votes
1answer
188 views

Why won't SparseArray let me store values with the head List?

When you attempt to define a SparseArray with elements that have the head List it complains: ...
7
votes
2answers
92 views

How do I make a string literal without having to escape backslashes?

I'd like to say something like: foo = @"\abc\def\ghi" instead of foo = "\\abc\\def\\ghi" How do I do this? This would ...
0
votes
0answers
35 views

How can I change this function for the better? [duplicate]

I have a function for an lfsr (linear feedback shift register): ...
2
votes
2answers
133 views

Can a pattern examine all partitions of a sequence?

Say I have a list: {a, b, c, d}. I'd like to check that the list has some partition, say {{a, b, c}, {d}} such that all the elements of the partition satisfy a ...
0
votes
1answer
55 views

Getting error Import::chtype when mporting 2D array of images [closed]

Suppose I have images = {{1.jpg, 2.jpg}, {3.jpg, 4.jpg}} Now I try to import all of them at level 2, ...
12
votes
1answer
315 views

Is everything in Mathematica ultimately stored as a rule?

My current understanding about Mathematica is that everything, at the lowest level, ends up as replacement rules. First question: is this true? Second question: does Mathematica "gloss over" these ...
0
votes
1answer
47 views

How to destructure local variables?

Why can't I use this Where[{iw, ih} = ImageDimensions[i], ...] instead of this ...
0
votes
1answer
49 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
120 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
2answers
65 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
1answer
93 views

Help with functions in Mathematica

Still learning how to do things in Mathematica. I want 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 ...
0
votes
1answer
43 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?
2
votes
5answers
221 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 ...
0
votes
0answers
30 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) ...
1
vote
1answer
107 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: ...
10
votes
1answer
340 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 ...
0
votes
0answers
56 views

Using NestList instead of Do [duplicate]

How can I express the following code using NestList: ...
10
votes
1answer
166 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: ...
28
votes
2answers
825 views

Is there a name for #1@#2&?

Why does the pure function # @ #2 & have no name? I'm asking because sometimes I find inelegant to write expressions like ...
13
votes
2answers
385 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 ...
4
votes
3answers
200 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 ...
17
votes
1answer
368 views

Confused about how Partition works

I have a problem about the padding list about Partition command. For instance, ...
2
votes
1answer
84 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 ...
20
votes
3answers
472 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 ...
0
votes
1answer
141 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 ...
4
votes
2answers
387 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
57 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: ...
2
votes
3answers
116 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 ...
1
vote
1answer
74 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 ...
13
votes
2answers
913 views

Scan vs Map vs Apply

I cannot understand the difference between Apply, Scan, and Map. I have tried to play with ...
10
votes
2answers
329 views

When must I use the Return function?

In a comment to my answer to this question, QuantumDot asks, "Where can I find more information on when I must use the 'Return' function?". I found this too deep a question to be answered by leaving a ...
20
votes
1answer
267 views

M9 performance regression for Fold?

Bug introduced in 8.0 and persisting through 10.0.2 or later I noticed an over 10x performance drop on Mathematica v9.0.1 (as Oleksandr R. commented, also v8) compared with v7.01 for this code: ...
18
votes
1answer
414 views

Shorter syntax for Fold and FoldList?

I find it tedious to write out the following: a = {1, 2, 3, 4}; Fold[f, First @ a, Rest @ a] f[f[f[1, 2], 3], 4] It ...
2
votes
2answers
99 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 ...