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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5
votes
3answers
153 views

Turning an expression into a function inside another function

Say I have an expression g=Sin[q]; It is easy to turn it into a function, and to perform manipulations on this function (this and variants of this were discussed ...
1
vote
2answers
58 views

How to compare and remove x-coordinates (and the associated y-coordinates) that are less than previous x-coordinates?

I am using Mathematica version 9.0 and am trying to compare and remove x-coordinates, and the associated y-coordinate, that are less than previous x-coordinates. Below is an example using sample data. ...
10
votes
1answer
495 views

GeoDirection and GeoDistance Memory Leaks: How to Recover the Memory?

Bug introduced in 7.0 and fixed in 9.0.0 The functions GeoDirection and GeoDistance have memory leaks. To see this, run the example functions below and watch as the Physical Memory Available in ...
0
votes
1answer
82 views
1
vote
1answer
50 views

How to define a number of infix operators with predefined relative precedences

Reading a number of questions about infix operator notations I want to ask if somebody could reimplement the problem below in a simpler way, say modifying ...
14
votes
5answers
653 views

Mathematica quine

A quine is a computer program which takes no input and produces a copy of its own source code as its only output. There are many trivial quines in Mathematica: ...
259
votes
25answers
34k 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 ...
1
vote
2answers
124 views

intermediate steps of a Mathematica operation

How to make a multiplication or division, the intermediate steps. The numbers can be rational - decimals? it seems the OP merely wants Mathematica to show him how to multiply and divide the way ...
1
vote
1answer
70 views

Program to demonstrate rotation according to quaternion values

On the Wolfram|Alpha website, I type quaternion(1,1,1,1) into the search field. Wolfram|Alpha shows a 3D transformation of the quaternion values representing the orientation of an object. I have 9 ...
0
votes
1answer
350 views

Mathematica Implementation of Householder’s Method

I typed the Householder code in this paper, which starts on page 7. The code is: ...
5
votes
1answer
602 views

How to implement Kemeny-Young method? (rank aggregation problem)

Prehistory I am trying to make some statistical analysis of some experimental data, arises from measurements made ​​on an ordinal scale. I faced with the problem of rank aggregation: to get from ...
0
votes
0answers
57 views

Mathematica requirements management [on hold]

Is there a way to use Mathematica notebook as a requirements document as it's possible in IBM DOORS ? ...
2
votes
1answer
69 views

Clean & efficient bounding box non-intersection test

I would like a quick test to tell me that segments $ab$ and $cd$ cannot intersect in the plane. If the maximum $x$-coordinate of $a$ and $b$ is less than the minimum $x$-coordinate of $c$ and $d$, ...
8
votes
3answers
364 views

Calculating integral by Romberg Algorithm

In my "Numeric Anasyis" course, I learned the Romberg Alogrithm to calculate the numerical integral. The Romberg Alogrithm as shown below: $$ ...
3
votes
2answers
73 views

How to define UpValues about the derivative of NBSpline when the length of knots is unknown?

Description In the book “Programming in Mathematica” 3rd by Roman.E.Maeder, the author gives a topic about A new Mathematical Function in section 8.4. For instance, for the following formula: ...
5
votes
1answer
93 views

Efficient upsampling of multidimensional array

I would like to efficiently upsample a multidimensional array. It's a 5000*5 matrix where each element is a submatrix 12*12 and it is that 12*12 matrix I want upsampled (to 24*24). The upsampling ...
12
votes
9answers
486 views

Generating a matrix using sublists A and B n times

I want to write a function that generates a square matrix from sublists. My sublists are a = Range[0, x, 0.5]; b = Range[0.25, x + 0.25, 0.5]; Suppose x=2, then I ...
1
vote
2answers
95 views

How to write a loop

I try to create a table which will describe traffic paths at a crossroads. Instead of using copy-paste repeatedly, I would like to write a loop. For example: ...
2
votes
0answers
62 views

What am I missing in this highly oscillatory integral?

I want to numerically integrate this equation (in python without calling Mathematica): $\int_0^\infty {\rm d}k f(k) J_v(r k) J_n(s k)$ where $f(k)$ is a non-smooth function, $J_v$ are the Bessel ...
7
votes
2answers
213 views

How to define the Bernstein function like the built-in BernsteinBasis?

We know the Bernstein function defined as below: $$B_{n,i}(u)=\binom n i u^i(1-u)^{n-i}$$ And we define $B_{n,i}(u)=0$ when $i<0 $ or $i>n$ In addition, the first derivative of $B_{n,i}(u)$ ...
361
votes
13answers
77k 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 ...
4
votes
1answer
53 views

How to add UpValues to a symbol to make a expression expanded normally?

Here is a implementaion of Bernstein basis function. I add the following UpValues to ...
4
votes
1answer
293 views

Maximizing functions with Which statements

I'd like to be able to find the maximum value that my Capex function (see below) generates. This is a fairly simple function so I could just add it up but I have more complex functions of a similar ...
10
votes
2answers
236 views

Checking the argument of user-defined function with side-effect method

Today, I answered a question of mine that asked two month ago. Please see here Now I would like to add the argument checking in this function. Then I used a method that Mr.Wizard answered ...
4
votes
2answers
318 views

A bug fix to mathematica 10.0.1.0

There is a bug in the Wolfram Symbolic Transfer Protocol Development in C (Windows). I described it in the next answer by myself, from which I summarize: One cannot successfully compile the ...
128
votes
1answer
23k 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 ...
2
votes
2answers
196 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
1answer
156 views

How to get the coordinates of points within an image?

How can I get the coordinates of an image, and make Mathematica draw the image from the coordinates found? I am interested in just the outlines of the regions. Here is an example of the kinds of ...
3
votes
1answer
96 views

A pre-parsed HoldForm

HoldForm holds an expression's parsed form not its actual "inputted form" e.g. ...
1
vote
1answer
117 views

Multiply out product of sums

For a specific quantum mechanical problem I need to multiply out operators in order to calculate a trace by hand. For example I need a Hamiltonian squared with $H^2$. The Hamiltonian contains of a few ...
5
votes
2answers
202 views

How do I “evaluate in place” programmatically? Need to evaluate Defer[] result in non-interactive setting

I need to evaluate the result returned from an external package, which contains Defer in it, but do this in a script without user interaction. I am not able to ...
12
votes
1answer
208 views

How to add AccuracyGoal and PrecisionGoal options in a numerical function?

There are many built-in functions that contain AccuracyGoal, PrecisionGoal and ...
3
votes
1answer
129 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 ...
7
votes
2answers
350 views

Association and rudimentary object-oriented programming

Doesn't Association provide us rudimentary object oriented programming via constructs like ...
2
votes
1answer
182 views

How can I invoke the solution of NDSolve to determine a parameter in my equation just inside NDSlove?

I am trying to solve a differential equation by NDSlove for $h(x,t)$. It reads $$h_t=h_{xx}-V_h-\lambda(t)$$ where $V_h$ is a given function of $h(x,t)$ denoted by ...
12
votes
4answers
607 views

How to implement dual numbers in Mathematica?

I wonder how can I implement dual numbers in Mathematica, so that all functions work well with them (as with complex numbers). Particularly, for each function $f$, ...
7
votes
1answer
101 views

How to select a submatrix containing similar elements from a matrix? [closed]

( This question is related but does not ( fully ) answer my questions. - Finding the position of similar elements in a matrix ) I have not written code yet, I am in the design phase of code for the ...
6
votes
1answer
71 views

Can Query operators be naturally cast as either Ascending or Descending?

One of the challenges of coming to grips with Query's on Association's and Datasets is ...
0
votes
0answers
38 views

Programming of basin of attraction for with memory iterative methods

I have made the programming for without memory method and i got the basin of attraction but i could not make it for with memory iterative method. I am sending you the programming of with memory ...
3
votes
3answers
519 views

Need help with exception handling

I have read the docs for Catch, Throw, and friends multiple times, and I confess that I find them utterly incomprehensible... ...
4
votes
1answer
131 views

How to check the option value?

Given that I have a function func as follow: To check the value of options, I using the step-by-step method If[] ...
54
votes
2answers
2k 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 ...
2
votes
1answer
83 views

Implicit derivatives in one line. How do I do it?

I have this little script to derive implicitly $PrePrint = # /. {D[y_, x_, NonConstants -> {y_}] :> y'[x]} &; Example: ...
0
votes
1answer
48 views

Write a function pollard[n, B] that tries to factor an integer n, using Pollard's p − 1 method with at most B iterations [closed]

This is what I got but it seems it's not working. When I test it, it just goes through and nothing gets returned. Is there something I'm missing? ...
6
votes
1answer
118 views

Is there a practical way to define a default value for missing keys in an Association?

It can be very useful to define background or default value for an object that can be incremented or otherwise modified. A simple (and for me, common) use is a counter: ...
3
votes
1answer
130 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
votes
1answer
101 views

Using function to transform a list

I have a list like that: {{Integer,String},....}, integer ranges from 1 to 900 and String "I" to "IV". And I need to find which pair of {x,y} each sublist is related to, so i can get a new list like ...