Questions about Mathematica's functional programming style, including the use of pure functions (Function[], #, &) and functions such as Map, Apply, Nest, and Through.
14
votes
3answers
349 views
Using pure functions in Table
I need a table with the elements made of pure functions and list elements. This is a simplified example:
I need a list as:
...
11
votes
2answers
402 views
Using a list of tuples in a pure function
I want to use a list of tuples within a function to make assignments.
Say I want to make assignments of the form
value[i,j] = val
What I have is a list of ...
50
votes
7answers
1k views
Functional style using lazy lists?
Let's say I want to answer the question "what are the first 400 palindromic prime numbers?"
The first approach that comes to my mind from the set of languages that I know is to use some sort of lazy ...
23
votes
12answers
818 views
Map a function across a list conditionally
It seems that this is a really basic question, and I feel that the answer should be obvious to me. However, I am not seeing. Can you please help me? Thanks.
Suppose I have a list of data ...
21
votes
6answers
870 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.
...
16
votes
1answer
278 views
Prefix operator with low precedence
The question is simple, but I will elaborate on the background as well for those interested in the idea:
How to define a new operator with specified precedence value?
Background
Mathematica was ...
14
votes
4answers
539 views
Is there a more elegant and efficient way to write brainf*** style loops in Mathematica?
I'm having some fun writing a brainf*** interpreter in Mathematica. See this wiki article for more info. It works nicely but I'd like to find an elegant, preferably functional, way to handle the ...
24
votes
3answers
275 views
FoldWhile and FoldWhileList
Mathematica has had NestWhile and NestWhileList for some time. But, to date, it has not implemented a built-in ...
8
votes
2answers
176 views
Cases[data,Colon[key,_]] vs. Cases[data,key:_] toward XPath, XQuery
Exploring methods to index and search tree-structured key:value pairs via named-entity index (key paths) as opposed to Position-based indexing.
Using Rule as ...
10
votes
4answers
230 views
Thread a function over a list and with a non-atomic 2nd parameter?
From the documentation, Thread's behavior on functions where the first parameter is a List and the second is an atomic expression, is this:
...
6
votes
4answers
404 views
Alternatives to While Loops?
I am using Mathematica to run a probabilistic simulation. Essentially, I have a list of members of a population (they only have one, numerical, attribute, so it's just implemented as a list of ...
6
votes
5answers
214 views
How to nest my own “times” function to get powers
I have a "times" function. I'd like to create a power function using it. It should look like this for an 6th power:
...
5
votes
2answers
175 views
Variant of the cutting-stock problem in Mathematica
I'm pretty new to Mathematica and am trying to learn to solve problems in a functional way. The problem I was solving was to list the ways in which I could sum elements from a list (with repetitions), ...
12
votes
2answers
281 views
Going full functional (Haskell style)
I'm trying to define some notation so that Mathematica code would be more functional, similar to Haskell (just for fun): currying, lambdas, infix operator to function conversion, etc.. And I have some ...
14
votes
3answers
424 views
How can I improve my code for drawing a tree?
This code draws a tree, but it's not in the functional style.
...
15
votes
1answer
222 views
Are there advantages to using additional arguments of common functions rather than alternative ways of calculating with lists?
(Apologies for the long question title.)
One of the interesting, if sometimes confusing, things about Mathematica is that there is always more than one way to do things. Even intermediate users can ...
12
votes
5answers
565 views
How to improve this code for solving the “Mr.S and Mr.P” puzzle?
Mr.S and Mr. P puzzle — "Formalization of two Puzzles Involving Knowledge", McCarthy, John (1987)
We pick two numbers $a$ and $b$, such that $a\geq b$ and both numbers are within
the range ...
11
votes
2answers
310 views
What's the most “functional” way to do Cholesky decomposition?
I can do Cholesky in a procedural style, such as:
...
15
votes
3answers
522 views
Programming a numerical method in the functional style
I am new to Mathematica and I would like to learn a bit more about functional programming.
At the moment I have assignments like programming different numerical methods (for integration: ...
13
votes
3answers
188 views
How to keep some of the results of the NestList
I'm using some iterative arithmetics to calculate wave propagation with the help of NestList. I have to use a small step size for iteration to guarantee the accuracy, which lead to too much data (e.g, ...
4
votes
4answers
224 views
How to transform Do loop to more efficient codes?
I'm new to Mathematica. Here is my original program: How to rewrite the Do part?
...
8
votes
3answers
316 views
Can this code be written in a more functional style
Referencing this question, I wonder if the following code can be written more concisely using a functional style, i.e. without For loops or ...
4
votes
2answers
116 views
Update a function avoiding infinite recursion
I am quite new to Mathematica and not completely familiar with functional programming. I am currently working with a function (call it foo) and wish to change its behaviour, for example, by adding 1 ...
1
vote
4answers
136 views
Order of operations for the Table function [duplicate]
Possible Duplicate:
Using pure functions in Table
I have run into a situation that I do not understand when trying to generate a nested list of pure functions. I have the following code.
...
1
vote
2answers
103 views
How can define a set of nested parameters
I would like to know how I to define a function with a nested set of parameters (or whatever you would like to call it). For example, how would I get the following function ...
0
votes
1answer
152 views
Arbitrary depth patterns/rules
Temporary message: I am now really confused. I am not sure how using Power and Unevaluated together works in the examples below.
While answering this question, I stumbled upon the following.
We ...
