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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4
votes
1answer
104 views

Construct a function that can generate a geometry by extruding a section

Toady I want to construct a geometry shown as below: I know the Mathematica has the functions like Cylinder, Sphere and so ...
0
votes
0answers
51 views

deleteduplicates Delete elements of a list [duplicate]

I have a math problem about Mathematica, I am looking help from you. I hope that you could help me. The Math Problem: list= { {0,0,1},{1,0,0},{0,1,0} ,{1,2,3}}; ...
0
votes
0answers
6 views

Where can I post my solution for “scrollable table with fixed headings”? [migrated]

As I'm new in the forum, my question is: Is there some special place for posting programming solutions?
0
votes
0answers
26 views

How to use ColorData[“Atoms”, “Panel”] as a clickPanel for ElementData[]

simple version ColorData["Atoms","Panel"] is a click-panel for RGBColors. With a single codeline, it can be transformed in a click-panel for ElementData[]. ...
7
votes
4answers
285 views

Computing the average over the values of the boxes surrounding a box in a grid

Recenty,I encounter a problem described as below: I have a table that owns many boxes,and each box has a sequence like 1,2,3,4,etc.In addition,every box has a value. Now I want to make the ...
0
votes
1answer
101 views

For-loop only executes first line in body

I have a simple For[] loop: ...
284
votes
12answers
50k 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 ...
9
votes
3answers
106 views

Implement settable properties

I am looking for advice on implementing the following. (It is possible that the answer is that it is simply not a good idea to do this.) I would like to have an object similar to ...
149
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 ...
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 ...
2
votes
1answer
134 views

How can I rewrite my code to make it simpler?

Two months ago,I written a function IRobot to caculate the $I_{xx},I_{yy},I_{zz}$ and $I_{xy},I_{xz},I_{yz}$,shown as below: ...
1
vote
0answers
39 views

Settings to disable global scope

I am building a fairly large application in Mathematica, and globally scoped variables are causing issues. I would like globally scoped variables to be out-of-scope for my expressions, except by ...
7
votes
1answer
706 views

Handling failed FindRoot calls

I want to handle FindRoot calls which did not converge (e.g "thrown" error message FindRoot::cvmit) ...
0
votes
3answers
109 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: ...
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. ...
4
votes
2answers
144 views

How to test whether an expression is a valid variable?

I would like to test whether an argument is a valid variable for functions like Solve and DSolve. For instance several ...
6
votes
1answer
140 views

Using least independent rectangle area to separate every point

Description I want to add vertical line and horizonal lines between data to make every point have an independent rectangle area. In addtion, every independent rectangle has a number ...
0
votes
1answer
121 views

Using Findroot within a loop

I am trying to get solution to an equation in a loop. The isolate equation works ...
0
votes
1answer
121 views

Defining a new matrix product of matrix function

Suppose I have two matrices A, B, whose entries are functions of x. Suppose they are 2*2. In the product, each entry is of the form $\sum_k A_ik B_kj$. There are two summands corresponding to k=1,k=2. ...
3
votes
1answer
62 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 ...
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.
1
vote
0answers
126 views

Is learning haskell still necessary to MMA users? [closed]

I'm major in Math and I had learned haskell for one week. But I'm unaccustomed to its coding style. I saw many people said if you want to master functional programming, then you shall use haskell. ...
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 ...
6
votes
1answer
254 views
0
votes
1answer
197 views

Obtaining the envelope of an oscillating function and perform fitting

There is an elegant way to obtain the envelope of an oscillation function explained here http://mathematica.stackexchange.com/a/27854/15966 My question is how to modify the code below so I can fit ...
1
vote
4answers
97 views

multiple sequential definitions, defining own set function

I want to define a function for doing multiple definitions, where I apply the same function f to all values, and definitions are done not at the same time but after ...
3
votes
2answers
135 views

Plotting: DensityPlot produces artifacts

I am trying to plot the electric potentials of bouncing balls using the following code: ...
0
votes
2answers
85 views

How to localize the symbols x,y, A, B in the following program? [closed]

I see a example in Paul Wellin's Programming with Mathematica An Introduction, 4th edition: ...
1
vote
2answers
173 views

More efficient implementation for comparing coefficient lists in a Do-loop

I'm wondering how to speed up the following code so it actually computes for $n=2$: ...
0
votes
0answers
66 views

Timing Differences

In More efficient implementation for comparing coefficient lists in a Do-loop link, george2079 posts in his first answer a piece of code that takes 352 seconds to compute. When I run this same piece ...
1
vote
1answer
50 views

Elements of a List according position in axis

({{a, b}, {c, d}}) a, b, c and d are Lists of 300 length. Their first 4 elements must specify their position in the column (1 column, 2 column, etc) and the ...
0
votes
1answer
119 views

How to represent the lines that are formed by the intersection of two planes?

I am trying to set up Brillouin zone and representing the lines that are formed by the intersection of two planes is part of my step. I have tried the sample sections from the graphics guide book, but ...
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 ...
1
vote
4answers
129 views

Plot roots of B(z) according to angle small to large

I have the following function: B[z_]=((z*(z - 0.5)*(z + 0.5))/((1 - 0.5*z)*(1+0.5*z))) I want to plot the roots this polynomial according to angel like below ...
0
votes
1answer
117 views

Differences between 'Solve' and 'LinearSolve' [closed]

Using the function 'Solve' I can do the following: Solve[a x + y == 7 && b x - y == 1, {x, y}] I get the following output: I want to get the same output using 'LinearSolve' instead. How ...
0
votes
0answers
37 views

Automatic Cuda/CPU code; Fast programme run [duplicate]

I have developed my thesis codes by means of Mathematica software in a .nb file format. Despite using the available Parallel code capabilities and doing all the numerical integrations by means of ...
1
vote
0answers
71 views

How to construct a coordinate system that owns detailed calibration in the 3D enviroment?

Recently,I write a program to demonstrate the forward kinematics of the SCARA robot.The code showed as below: Using this function to construct the BigArm and ...
0
votes
2answers
46 views

How to output (anything) if any error happens

I have long code which goes through iteration process. some times I get error messages. I want to get the iteration numbers (or any kind of output indications) when errors happen. for example, how ...
6
votes
3answers
298 views

How to eliminate the need to double evaluate a Manipulate so that a Module in its Initialization section works?

Using V 8.04 on windows. I think this issue might be related to the fact that Mathematica reads main body the Manipulate before evaluating or running the Initialization option. Or, might be ...
5
votes
1answer
172 views

Higher RAM handling by 32bit Mathematica [closed]

Can 32 bit Mathematica run program which requires more than 4GB RAM ?
1
vote
2answers
83 views

Clearing arguments passed to a Module

Is there a possible way to clear the arguments passed to a module to release some memory. I believe that arguments passed to modules are passed by value rather than pass by reference. e.g. I have the ...
0
votes
1answer
111 views

Using a LocatorPane

I have a network of a power grid where the edge are the power lines and the vertices are loads or generators. I was wondering how I can import an image into Mathematica to derive some sort of ...
8
votes
1answer
99 views

CSS Selectors for Symbolic XML

Symbolic XML is a convenient way of managing XML in Mathematica, at least for casual use or small tasks. Here and elsewhere you can find examples of XML handling in Mathematica, including XSLT/XPath ...
5
votes
3answers
220 views

Split list of states by run lengths and discontinuous changes in state

I was asked to look into writing some simulation code for a user, where the simulation output (x) would oscillate between three possible states: ...
4
votes
4answers
552 views

Skip other If conditions

I'm trying to write a code to "random" move in a matrix but it can't go to a certain position if it has a certain value (in this case I'm using the number 2). How do I make it to skip all other If ...
2
votes
0answers
46 views

Simulating a system of nonlinear ODEs?

I was trying to simulate a system of ODEs on Mathematica in an effort to try to understand how to muck around with Mathematica but for some reason the following lines of code do not yield any results; ...
0
votes
0answers
77 views
13
votes
1answer
273 views

Evaluation indicator for a notebook

I have a GUI with a number of TabView and other Manipulate controls. Sometimes clicking from one tab view to the other can take ...
13
votes
1answer
355 views

Is it possible to use Begin and End inside a Manipulate?

May be someone can explain why I can't use Begin["context`"] and End[] inside a Manipulate ...
1
vote
0answers
112 views

Finding Values of All Nine Constants in q-hypergeometric Equation

I suspect that an identity of the form $$\sum_{j=-n}^{j=n}(-1)^jq^{j(5j+1)/2}=\sum_{r=0}^{n}f_{ar+bn+c}(-1)^{n-r}q^{(n-r)(dr+en+f)/2}\frac{(q;q)_{gr+hn+j}}{(q;q)_{n-r}}$$ for $a, \dots , j$ integer ...