Questions on writing non-trivial programs in Mathematica. Do not use this tag for questions on plotting/graphics or for questions on doing mathematics with Mathematica, where the focus is more on the math than the program.

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284
votes
12answers
51k views

Where can I find examples of good Mathematica programming practice?

I consider myself a pretty good Mathematica programmer, but I'm always looking out for ways to either improve my way of doing things in Mathematica, or to see if there's something nifty that I haven't ...
150
votes
19answers
13k views

What are the most common pitfalls awaiting new users?

As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
110
votes
1answer
21k views

Mathematica Minecraft

Some time ago I asked myself: with all these great graphics and interactive capabilities of Mathematica, what kinds of 3D games can be implemented in it? And the answer which came to mind is ...
86
votes
3answers
3k views

Performance tuning in Mathematica?

What performance tuning tricks do you use to make a Mathematica application faster? MATLAB has an amazing profiler, but from what I can tell, Mathematica has no similar functionality.
84
votes
3answers
11k views

Alternatives to procedural loops and iterating over lists in Mathematica

While there are some cases where a For loop might be reasonable, it's a general mantra – one I subscribe to myself – that "if you are using a ...
74
votes
1answer
2k views

Programmatic formatting for Mathematica code - possible?

It seems to be both an interesting programming challenge and a very useful practical application to have a Mathematica program which would allow one to pretty-print Mathematica code, so that it is ...
72
votes
7answers
6k views

Struct equivalent in Mathematica?

I really miss having something like a struct in Mathematica. I know of (and regularly use) a couple of programming techniques which feel like a ...
52
votes
2answers
7k views

Is there an open source implementation of Mathematica-the-language?

I've seen questions before such as "What is the best open-source equivalent for Mathematica?", but that specific question (and that line of inquiry in general) cares more about the computer algebra ...
51
votes
2answers
2k views

Flatten command: matrix as second argument

One thing I could never wrap my head around is how Flatten works when provided with a matrix as the second argument, and the Mathematica help isn't particularly ...
48
votes
5answers
3k views

What does the construct f[x_] := f[x] = … mean?

This question mentions "x := x = trickery". What does defining a function as f[x_] := f[x] = ... do and what is it good for?
45
votes
10answers
8k views

How to check if a 2D point is in a polygon?

Background: I use code from An Efficient Test For A Point To Be In A Convex Polygon Wolfram Demonstration to check if a point ( mouse pointer ) is in a ( convex ) polygon. Clearly this code fails for ...
43
votes
2answers
1k views

What are the best practices / most common / idiomatic ways to report errors in Mathematica?

In particular, what are the best ways to report errors about incorrect arguments to a function? Checking for the correct arguments is relatively easy using patterns, but how to report an informative ...
42
votes
6answers
2k views

Functions vs. patterns

Every time I define a new function, I wonder which construct I should use: true functions obtained by using Function, or rule-based syntax. For example, these are ...
41
votes
4answers
1k views

Automatic e-mail/text message when a calculation has finished?

Sometimes Mathematica takes quite a while to finish calculations and it would be convenient to be able to move away from the computer while it is working. I was wondering if there is any "clever" hack ...
41
votes
2answers
2k views

What is a Mathematica packed array?

A simple sounding question with a few sub questions: What is the difference between unpacked vs packed array? Are packed arrays more space efficent, how much so? Are packed arrays more time ...
39
votes
8answers
2k views

Updating Wagon's FindAllCrossings2D[] function

Stan Wagon's Mathematica in Action (second edition; I haven't read the third edition and I'm hoping to eventually see it), demonstrates a nifty function called ...
38
votes
3answers
684 views

The clearest way to represent Mathematica's evaluation sequence

WReach has presented here a nice way to represent the Mathematica's evaluation sequence using OpenerView. It is much more clear way to go than using the standard ...
38
votes
4answers
3k views

Creating Mathematica packages

I'm building a package to help me write packages and their documentation. In this post I explained how to make a package and its documentation. In the answer I provided I describe how to build a very ...
37
votes
9answers
3k views

Having used Mathematica as a “gateway” language, where to from here?

I have been using Mathematica for about a year. It is the first language that I have attempted to learn. I'm still very much a newbie, but there are moments I feel more like I am waving than drowning. ...
36
votes
2answers
940 views

Reconstruct text pages cut by shredder

Q1: I have a page of printed text file, but it was cut by a paper shredder (from top to bottom). You can download all the paper fragment here. There are some examples of them. How can I reconstruct ...
35
votes
3answers
3k views

Metaprogramming in Mathematica

Being functional, and having no "quotation", i.e. essentially treating data and programs semantically same, Mathematica seems naturally capable of doing metaprogramming. But could anyone construct a ...
35
votes
4answers
2k views

How do I evaluate only one step of an expression?

I am looking for a simple, robust way to evaluate an expression only one step, and return the result in a held form. The definition of a single step is ambiguous, and this itself is probably worthy ...
35
votes
1answer
1k views

Once more on object orientation in Mathematica: does it have to be so hard?

Recently I came across a set of problems which would be solved most easily within an object-oriented approach. I first attempted to solve them by other means, but found the complexity of the code ...
34
votes
9answers
7k views

Generating a Sierpinski carpet

I am trying to draw a Sierpinski_carpet. I have code that works, but I think there is a more elegant way to do than my way. Maybe I couls use Tuples or ...
34
votes
2answers
1k views

Performance tuning for game solving (peg solitaire | senku)

There's a game I saw at a friend's yesterday, that I often see at people's homes, but never for enough time to think on it too hard. It's called peg solitaire (thanks @R.M). So I came home and I ...
34
votes
1answer
575 views

Export Code to Pseudocode?

I'm writing a paper and all my code is in Mathematica. The snippets are mostly simple, and consist of loops, maps, variables, and conditionals. I'd like add it to my paper, however, not many academic ...
33
votes
4answers
2k views

How can I implement dynamic programming for a function with more than one argument?

Dynamic programming is a technique for avoiding the repeated computation of the same values in a recursive program. Each value computed is immediately stored. If the value is needed again, it is ...
33
votes
2answers
616 views

How safe is the use of Block and Internal`InheritedBlock

For many questions on this site answers are given which suggest to use Block and, especially for more advanced topics, ...
30
votes
3answers
3k views

How to create a progress bar?

I would like to create a progress bar tool that allows me to see how my computations are going. I found answers to this question on many sites, I even found a package for it ( ...
29
votes
4answers
2k views

Can Mathematica be regarded as a software prototyping environment?

I am an undergraduate student, starting to use Mathematica to model simple physical chemistry problems, as a prelude to a summer internship in a computational/theoretical chemistry group. The solution ...
29
votes
4answers
2k views

Finding a percolation path

I would like to examine percolation on a random lattice. To be exact, I wish to find the minimum length of a 'bond' needed such that the leftmost site can be connected to the rightmost site. Here is ...
28
votes
5answers
2k views

Are there any cases when For[] loops are reasonable?

To my mind the only reason for the existence of For[] loops in Mathematica is to allow new users with some experience in procedural programming languages to write ...
27
votes
1answer
1k views

Recommended settings for git when using with Mathematica projects?

Background I'm relatively new to git — currently overseeing an offshore .NET-based development project on GitHub within a private business account, but little experience beyond that. I'd like to set ...
26
votes
5answers
941 views

Voronoi diagrams for generators other than points

Any suggestions how to determine Voronoi diagram for sites other than points, as e.g. in the picture below? Input is a raster image.
26
votes
3answers
4k views

ListPlot with each point a different color and a legend bar

I would like to generate a ListPlot with the color for each point in the plot corresponding to a particular value (not associated with the position in the plot). I'd then like to add a legend ...
25
votes
4answers
953 views

Question about collections of custom GUI controls for Mathematica

Background: I have only recently begun programming GUIs in Mathematica, so I have a continuous need for custom controls. I needed a scrollable list control and with the help of Google I found a ...
25
votes
3answers
663 views

Is there a convenient way to copy/paste text-interspersed SE code snippets into Mathematica?

Is there a way to copy and paste code snippets from SE to Mathematica if these snippets are interspersed with text? Like e.g. in Morphing Graphics, color and location in both the question and answer, ...
25
votes
2answers
1k views

when is f@g not the same as f[g]?

I have always thought that f@g will give the same result as f[g] in all cases, and it is just a matter of style which one to use ...
25
votes
4answers
6k views

How to use Mathematica functions in Python programs?

I'd like to know how can I call Mathematica functions from Python. I appreciate a example, for example, using the Mathematica function Prime. I had search about MathLink but how to use it in Python ...
24
votes
4answers
898 views

What tools can help in realizing tail recursion?

I had nice discussions with Leonid and Rojo that got me interested in tail recursion. Tail recursion is not always easy to realize with Mathematica, so it would be nice to have some tools to help with ...
24
votes
3answers
872 views

Getting serious about Mathematica programming

I'm at a point in my Mathematica journey where I need to be a little bit more strategic about my coding. Presently, I have a bunch of notebook files organized using the filesystem of the OS and ...
23
votes
6answers
1k views

Mathematica Destructuring

Context I'm writing a function that look something like: ...
23
votes
3answers
688 views

Is using undocumented functionality a Bad Idea™?

Mathematica has a lot of very useful undocumented features. For example a hash table, a built-in list of compilable functions, additional options to CurrentValue, ...
23
votes
4answers
967 views

Are there suitable versioning systems for Mathematica notebooks?

I am considering a project using Mathematica and openCL. I know that the openCL C source code can be tracked. Has anyone used a versioning site or software so multiple developers can modify a common ...
23
votes
1answer
375 views

What can be used as the second argument to Return on your own functions?

Having found out about the second argument to Return I played a bit with it, and the following tests all resulted in ...
23
votes
2answers
996 views

Do I have to code each case of this Grid full of plots separately?

I have written some custom functions to draw multi-panel graphs like this one: It's done by passing a matrix of (custom) plotting functions to a MultiPanelGraph ...
22
votes
4answers
1k views

Is it necessary to have a prior computational background or is it possible to learn Mathematica as a first programming language?

I have a background in economics and I'm very interested in learning Mathematica but I'm afraid of starting out because I have seen that most programmers already have a good background in some kind of ...
22
votes
1answer
2k views

Programmatically retrieving e-mails from a remote server

Mathematica has a function for sending mail (SendMail) and can import the MBOX format. But what I'd like to do is ...
22
votes
1answer
499 views

On drilling holes with minimal redundancy (and with colors!)

The old Mathematica package Graphics`Shapes` featured the function PerforatePolygons[], which drilled a hole in any ...
21
votes
6answers
1k views

Can this be written well, without loops?

Inspired by this question I would like to know if the following code can be written without explicit loops (For, While, etc.) in a clean, efficient and non-contrived way. I have been unable to do so. ...