Questions tagged [code-review]

This tag is intended for the review and improvement of style for already functioning code. It not meant to change the objective of the code.

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32
votes
2answers
834 views

Copying one symbol into another

I would like to know how can I completely copy one Symbol to another. When I say copy, a refer to UpValues, DownValues, ...
29
votes
8answers
2k views

Splitting words into specific fragments

I am looking into splitting words into a succession of chemical elements symbols, where possible. For example: Titanic = Ti Ta Ni C (titanium, tantalum, nickel, carbon) A word may or may not be ...
14
votes
9answers
897 views

Thread over list in different levels

I have these two lists, both with the same length in the first dimension: ...
15
votes
1answer
2k views

Poisson solver using Mathematica

I am looking for some help with a Poisson solver I am writing in Mathematica. The code is quite long with Arrays plugged in, so the full details can be found at http://pastebin.com/uSrSDcW6 I am ...
15
votes
4answers
1k views

Button evaluation inside DynamicModule

Someone know why this Button works when clicked: ...
44
votes
10answers
7k views

Programming paradigm change

I'm new to Mathematica, I've been learning by myself, and, being a Java developer for some time, it makes it hard to adapt. I've tried to solve a Reddit challenge, and I came up with this solution: <...
13
votes
4answers
2k views

Simpler way to fill date gaps with zero values

One basic problem when working with data like sales and dates is the case where you don't have sales in all days, so you have to fill it to take information as average or to make a plot. See this toy ...
5
votes
3answers
2k views

Using DSolve to solve for x[t,parameter]

I'm trying to solve an ODE with two independent variables (a cannon firing from a cliff incorporating wind resistance dependent on velocity). I've tried the following for the x-component: ...
5
votes
2answers
254 views

how to generate repeatable Unique streams?

I need to label some data in arbitrarily nested ragged lists, with a stream of unique labels. It's very convenient if the labels are consecutive integers, starting at ...
11
votes
1answer
338 views

Fine tuning compiled code that computes dilogarithm function

As an exercise in writing a good Compile function, I want to do the simple task of coding a routine that outputs the real part of the dilogarithm function ...
38
votes
1answer
2k views

May the Fourth be with you

Happy Star Wars day. I was playing around with the image manipulation functions in Mathematica in an attempt to recreate the Star Wars crawl. There's an HTML/CSS implementation which is in my ...
12
votes
3answers
745 views

How to check the validity of an option value

I have a user-defined function, func, which takes the following form: func[arg1, arg2, options] Here is the actual code ...
7
votes
2answers
1k views

Elegant way to handle columns operations

Inspired by this question from @sjdh and by my recurrent use of columns operations in database sets, I was looking for one way to make columns operations more symetric, so I can handle with matrix and ...
4
votes
3answers
305 views

Is there something wrong with this piece of code involving Manipulate?

I am playing around with the Manipulate sentence. I think the following code is right, and actually Mathematica 9.0 doesn't return any error message, but I am ...
6
votes
2answers
203 views

Looking for feedback on this function

I'm not sure this is an appropriate question; if not, I'm sure someone will close it :) I've got the following function, listed below; its job is to accept a graph (function) presented either as a ...
21
votes
2answers
1k views

Simulating molecular dynamics efficiently

The following website offers a very nice molecular dynamics simulation: http://physics.weber.edu/schroeder/md/. It is pretty neat and quite a few physical phenomena can be described from that small ...
5
votes
6answers
2k views

Why is this Mandelbrot set's implementation infeasible: takes a massive amount of time to do?

The Mandelbrot set is defined by complex numbers such as $z=z^2+c$ where $z_0=0$ for the initial point and $c\in\mathbb C$. The numbers grow very fast in the iteration. ...
12
votes
1answer
877 views

Problems with stress distribution using FEM

I'm trying to get the displacements u(x,y) and v(x,y) of a beam simply suported, the stress distribution in the middle section should be a linear function: but i'm getting this: My code is: ...
4
votes
2answers
606 views

Collatz Tool Box — any speed ups possible?

I have created a tool box for experimenting with the Collatz conjecture. Info here: Wolfram MathWorld and here: Wikipedia The patterns I have found allow us to make the conjecture jump through some ...
13
votes
2answers
1k views

Parsing a CSV file using Interpreter

The new Interpreter functionality in version 10 looks like it has the potential to make parsing custom data formats very easy. I'm trying to create a CSV parser. ...
7
votes
1answer
282 views

The curious case of missing random-walking particles in the box

Note: I added the entire code I wrote below to generate the initial configuration and have explained step by step what each part of the code does Kindly bear with the code and the explanation. Since ...
1
vote
2answers
198 views

How to deal with the condition that a function own many options?

Assming that I have a function myFunc which has some options. ...
6
votes
1answer
316 views

What is wrong with this code? (Usage of FunctionInterpolation and how to make code efficient)

I am trying to create an interpolation out of a function that comes from an improper integral. The end goal is to make a 3d plot over a specific region. Specifically, I have the following code: ...
3
votes
2answers
1k views

Numerical Integration Via Adaptive Simpson's Method

I have written a code that uses the Adaptive Simpson's method to approximate integration. For those who are unaware of this Adaptive Simpson's method; Adaptive Simpson's method In my code, I count ...
15
votes
6answers
821 views

Better way to sort course grades

I use the following code to create a histogram of grades. Grades are provided as a List of strings such as "A-", "D+", "E" (don't ask), etc. The +/- substitution hack is necessary to sort the grades ...
2
votes
1answer
663 views

Passing function as argument

I've been mucking around with passing functions as arguments to other functions and via trial and error seem to have something that works. I was wondering if someone could have a quick look at some ...
1
vote
1answer
393 views

Lookup construction using data matrix and Reap/Sow versus AppendTo`s

I am a user of MMA9 and made my own kind of Lookup, which is now a standard command in Version 10. In my program there is a section in which by means of a StringReplace[ ]-command containing a lot of ...
41
votes
0answers
2k views

Fast Spherical Harmonics radiative transfer

This is a rather specific question and I apologize for spamming you with some lengthy code. But it could be interesting for some reader and maybe you can help out, so please bear with me. I am using ...
24
votes
1answer
984 views

Strategies for solving problems involving searches

As an example of a search-oriented problem, consider finding all constrained $n$-colorings of a graph. An "$n$-coloring" associates one of $n \ge 1$ colors to each vertex in such a way that no edge ...
13
votes
7answers
926 views

How to sort digits in a string while keeping other characters untouched?

Now there is a string with digits and letters, for instance, "95uge678r3gi89hgfe30kgh063d51". And the expected output is ...
15
votes
3answers
445 views

Clever use of DownValues, or failure to understand the “Mathematica Way.”

I needed to look at the changes in the values of about 4000 items from one year to the next. I have a table with identifiers and values for each year. Not all of the items are in each list. The ...
15
votes
1answer
324 views

Extract what symbol is set by SetDelayed, Set, TagSet, UpSet, SetAttributes, etc

One of the recent features of the Mathematica Plugin for IntelliJ IDEA (www.mathematicaplugin.halirutan.de) is a Structure View which let's you see information about several definitions that are done ...
3
votes
1answer
130 views

User implemented SHA-1 isn't outputting correct hash

EDIT: I'm actually Thinking the issue is in the initialization phase, where we pad the message with 1's, 0's, and the message ...
14
votes
2answers
944 views

What's the most “functional” way to do Cholesky decomposition?

I can do Cholesky in a procedural style, such as: ...
5
votes
0answers
100 views

Techniques in debugging with preview of possibly large expressions + garbage collection issues

First of all, all appreciate all suggestions how to rephrase the title to make it more friendly. Here's the background: Let's say your top level procedure flow is complicated, involves url calls, ...
5
votes
3answers
3k views

How to fix BodePlot that comes with Mathematica?

I am using Mathematica to go through the examples and exercises on the book Modern Control Systems, 6th edition by Dorf. On page 605, there is a table (Table 8.5) with the Bode plot for several ...
5
votes
1answer
150 views

Can someone please explain the code from another question

Source: Position of a pattern-matched part of an expression Can someone please explain the following code by Leonid Shifrin. ...
12
votes
1answer
544 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 ...
4
votes
1answer
135 views

How to index multi-dimensional vectors in NDSolve/WhenEvent?

I want to solve a system of coupled ODEs using NDSolve with WhenEvent. But I'm having a hard time trying to index the state ...
5
votes
5answers
463 views

Rotating squares

I have here an example of how a rotation matrix operates a parametric representation of a square. ...
4
votes
1answer
204 views

Feedback on my Subscript code

I have written a code, and I need a little feed back.. I want to make the Subscript distributive across (1) addition and (2) multiplication to mimic short-hand for ...
3
votes
1answer
579 views

Runge-Kutta-2 on System

After spending some time using the Mathematica documentation and this Mathematica.SE answer, I implemented the Runge-Kutta-2 routines. I am hoping someone can validate what I did and tell me that it ...
2
votes
1answer
3k views

converting Matlab program to Mathematica code

I have the following Matlab program; ...
2
votes
1answer
43 views

User Implemented SHA-1 is failing for strings of length >512 bits

So, earlier, I posed a question regarding getting a user implemented SHA-1 hash function to work correctly. Well, I fixed the problems, cleaned it up a little bit, but now I have the problem for when ...
2
votes
1answer
266 views

Performance on Binomial Deviate is slow

I hope I won't get spanked for reposting. This is related to a previous question discussed here: Performance on Multinomial Deviate is slow. but this version is simpler because it is a binomial ...
1
vote
3answers
302 views

professionalize/optimize my code that calls a function

I have the following construction, which defines a function that I subsequently call in a loop multiple times. I use this very often, but I have never looked into if there is a more professional way ...
0
votes
1answer
564 views

Eigenvalues and Eigenvectors Order [duplicate]

Say I have a list of eigenvalues and eigenvectors produced from a matrix $M$ using the command {eig1,eig2}=Eigensystem[M], which will return the eigenvalues with ...
-1
votes
1answer
141 views

How to directly/conveniently use variable names as filenames?

Purpose To use variable name as file name conveniently. Code Special thanks to @J.M.'s tips! ...
8
votes
1answer
358 views

Selecting a list from a list of lists

In working through Programming Paradigms Via Mathematica (A First Course) I have come across this two part question: A permutation of length "n" is a list of the first n positive integers in some ...
6
votes
1answer
199 views

Path construction using `Nearest` shows ill behavior?

I have a dataSet that I'm trying to sort choosing a starting point and going to its nearest neighbor, and then to its nearest neighbor and so on. To do so, I've ...