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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3
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1answer
133 views

Programming for matrix manipulation

I want to write a programme which operates on nd x nd matrices. The programme looks the matrix as a n x n block matrix where ...
3
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2answers
122 views

Apply Collatz Funtion to solve and print the answer

Good day to all! The objective of my task is apply the collatz function for a number x1 and print the exact number of iterations until ...
3
votes
2answers
114 views

How to define a nestable Baseform function, BaseForm output becomes BaseForm input

Mathematica won't change a number's BaseForm recursively: 63969 // BaseForm[#, 16] & // BaseForm[#, 8] & // BaseForm[#, 2] & Well, I inspected former ...
3
votes
2answers
270 views

Defining an anonymous function using another function but with fewer arguments

In MATLAB you can use an anonymous function with another function to define a new function with fewer arguments as long you define the excluded argument before, e.g. ...
3
votes
2answers
152 views

Bare symbol invocation fails but not if used with an argument

How to achieve the following behavior on a symbol f? Background: The main goal is to use the symbol to tag an abstract data structure where downvalues are used to store information. Only defined ...
3
votes
1answer
368 views

How does FindInstance work?

I was asked a question one day: find an integer n such that the first five digits of 5*7^n is 12345. It's very nice that I can quickly write code like this: ...
3
votes
1answer
135 views

Difference between Directory[] and NotebookDirectory[] .. a trailing /?

The following was the code: Directory[] NotebookDirectory[] The output was ...
3
votes
1answer
130 views

How to make a pattern to change x^(2/y) to (x^2)^(1/y) for any x and y?

This might have been asked before. Please let me know if it is. I was looking at an interesting Mathematica question in students forum and trying to solve it, and a chance to learn more about ...
3
votes
1answer
330 views

Do “objects” in Mathematica have to be declared?

A while ago I learned a trick which allows one to imitate object-oriented programming in MMA using SubValues: ...
3
votes
1answer
512 views

FindMinimum, NMinimize, etc. with external process

I was hoping to be able to use MMA's minimization power to work with an external process. I want to minimize the function 'TryThisNumber[x_]' which sends the value of x to something external and gets ...
3
votes
1answer
202 views

How to replace While construct to NestWhile(functional-style) correctly?

Recently,I find the program of @J.M. about Get a "step by step" evaluation in Mathematica is a very useful example for learning Mathematica programming. In the function ...
3
votes
1answer
81 views

EndOfFile error

I have a LARGE file (14.6 GB) that I want to separate into several smaller files. Because of its size, using Import/Export is not feasible, I think the most reasonable way of handling this would be ...
3
votes
2answers
215 views

My code for solving n queens problem Compile Failed

I want to make my code for solving n-queens problem faster, but it seems that MapIndexed can't be compiled. Mathematica return CompiledFunction::cfse: Compiled ...
3
votes
1answer
85 views

Fastest way to select the longest cell

I'm trying to learn low-level notebook programming and I have a question. Is there faster way to select the longest cell in a notebook than this: ...
3
votes
2answers
549 views
3
votes
1answer
519 views

Nested Sums to multiple sum

I would like to automatically "move nested sums to the left". I mean, just take out of an expression all the summations and go from a nested Sum to a multiple sum. Something like starting with: ...
3
votes
1answer
134 views

How can you get the area of a region from an image?

Suppose we have a square of side "L" m, How can I calculate the hatched area, if the corners of the square are centers of circles. It can be generalized to any region? edit: This is the result I ...
3
votes
1answer
94 views

Is it possible to update Dynamic objects even when they are off screen?

I am using Dynamic and DynamicModule to display graphics/statistics generated from a long-running set of parallel tasks. The ...
3
votes
1answer
145 views

Image background subtraction using parallel computing

I am developing a program for pattern recognition. I want to use the parallel computing to get a real time application. I have two cameras where each one gives n frames/second. I need to process the ...
3
votes
3answers
120 views

Composing function returning list and function taking multiple arguments

What is the easiest way to compose a function that returns a list of $n$ elements with a function that takes $n$ arguments. If I know this $n$ a priori, I can do something like ...
3
votes
1answer
148 views

Writing this loop in Mathematica

OK, so I've never had to write a line of Mathematica code (except for using it interactively as a calculator), but for this it looks like I have to. If someone could provide me with the code for the ...
3
votes
1answer
141 views

Why even try the semantic constraints, if expression can't match the pattern structure?

This result is unexpected: Trace[MatchQ[{7}, {_?NumberQ, __}], NumberQ] (* -> {{NumberQ[7], True}} *) Why evaluate ...
3
votes
2answers
525 views

Matrices and polynomials: MMA 8 vs. 9?

I want a function to take a polynomial from a list, plug a certain matrix T into that polynomial, and return the answer as another matrix. My program uses the applyPoly function suggested by a user in ...
3
votes
1answer
293 views

How to determine cluster membership using FindClusters?

I have a 1000 by 3 data matrix in which for each person we have 3 scores. I want to cluster those persons into 8 cluster using Agglomerative method. I did the clusetring by: ...
3
votes
1answer
105 views

Generating Palindromic_number [duplicate]

I'm trying to construct Palindromic_number, I came up with this code: ...
3
votes
1answer
75 views

Combination of CellPrint and PrintTemporary, or DisplayForm for Cells

I'm programmatically generating some formatted output that generates a cell in the form of a Cell[] expression. For instance, the output might be ...
3
votes
1answer
451 views

Control over depth-first scan and breadth-first scan

Is there a way to conditionally take control/modify the flow during a depth-first scan or the breadth-first scan ? Say, for example, if a particular node if found, consider it as a leaf-node and ...
3
votes
0answers
180 views

Distance Time Warp (DTW) function implementation in mathematica

The DTW (Distance time warp) is given here http://en.wikipedia.org/wiki/Dynamic_time_warping There is an implementation of DTW in R as well as MATLAB. However i am unable to find something for DTW in ...
3
votes
2answers
223 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 ...
3
votes
0answers
61 views

Can BreadthFirstScan be modified?

I would like to obtain a "slick" implementation of A*-search algorithm on Graph objects, using the built-in BreadthFirstScan (if that is possible at all). I noticed that BreadthFirstScan is static in ...
3
votes
0answers
367 views

A* algorithm for finding shortest path in a graph

FindShortestPath finds the shortest path between two vertices in an edge-weighted graph, allowing a choice between the Dijkstra and Bellman-Ford algorithms. In my (limited) understanding, both of ...
3
votes
0answers
189 views

Using NVIDIA 3D Shutter Glasses with Mathematica

Mathematica has great capabilities to display 3D Graphics rendered to the 2D screen. This should make it perfectly suited to use the Graphics3D system together with an NVIDIA Graphics card, a 3D ...
3
votes
0answers
44 views

Is it possible to enclose code into collapsible/expandable regions? [duplicate]

In some programming languages (e.g. C#, Visual Basic) there are language constructs that have no effect on the execution of code whatsoever, but exist solely to allow grouping fragments of code into ...
3
votes
0answers
289 views

How to compute the Lovász number for the given graph in Mathematica?

Here is a graph whose adjacency matrix is ...
3
votes
0answers
57 views

How can I append Mathematica variables to an output file preserving both names and values? [duplicate]

I have a Mathematica program that calculates a series of large vectors that I need to save for future reference (in addition to some scalar values). I want to save all these to a file, tagged by their ...
3
votes
0answers
246 views

Malliavin Derivative with Mathematica is it possible?

Is it possible to define a Malliavin calculus with Mathematica 9? Consider a random variables on the Wiener-space $\Omega=\mathcal{C}([0,1])$ of the form ...
3
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0answers
165 views

I am missing a function like HoldPattern

Temporary message: I am planning to edit this question, making the examples less confusing and by moving the things that are confusing to a separate question For any confusion about expressions that ...
2
votes
5answers
459 views

How to leave function unevaluated programmatically?

Is it possible to write a function in such manner, that it can be either evaluated or left unevaluated? This is a general question. Sample below is just a sample. No need to find solution for this ...
2
votes
2answers
1k views

optimization problem with NDSolve

I want to minimize the function fcc. When fcc is calculated for a specified point the answer is correct: ...
2
votes
4answers
523 views

Using the result of Solve in subsequent calculations

I'd like to know how to use the results of Solve in later calculations. Here's what I'm doing now: This is my expression ...
2
votes
1answer
130 views

Odd edge-case behavior of Block

In this example, Block is used to localize the variable cache as used in the function g when called from the function ...
2
votes
1answer
834 views

Using triangulation

I have been presented with 3 known points and the power densities at those points. I need to use those points to find the location of the actual antenna which is generating the signals. Power ...
2
votes
3answers
177 views

Using Nest inside NestList

I need results like this: {Cos[Cos[x]], Sin[Cos[Cos[x]]],Cos[Cos[Sin[Cos[Cos[x]]]]], Sin[Cos[Cos[Sin[Cos[Cos[x]]]]]], ... } I've tried to use ...
2
votes
3answers
195 views

How can I find the points of B Spline functions for a specific range?

Based on this question: I have a list of bspline functions (nearly 1000) provided by applying BSplineFunction to a list of points. I want to get the points each of ...
2
votes
5answers
133 views

GatherBy based on condition imposed on index variable

Excuse me. This might be user specific question but I need your help. I have an indexed data, where positive integers are used for indexing data. I am trying to group data putting condition on index ...
2
votes
3answers
189 views

How can I use NestWhileList instead of While in this case?

OK, the problem occurred when I challenged with Project Euler No. 10 The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17. Find the sum of all the primes below two million. My code is: ...
2
votes
2answers
202 views

How to replace data in a list (tree) in a functional Mathematica way?

I have list containing 2D points in various groupings, i.e. points, lists of points (figures), lists of lists of points (patterns) and finally a list of patterns. The list also contains other data, ...
2
votes
2answers
432 views

Mapping multiple functions

This question was part of a course on Mathematica written in 1998. Each of the functions f1, f2, and f3 defined below has a root near x=2. Map an anonymous function involving FindRoot[] onto ...
2
votes
3answers
280 views

How do I construct a pure function to extract data fields from records that are strings?

How can I get from data segment format to the final segment format with a pure function? The data fields are fixed length. There are no separators between the fields. a) list ...
2
votes
3answers
139 views

How to extract both first and last rows of each group from unbalanced panel data

This is a follow up question form my last question click here. I have unbalanced panel data such as : ...