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.

learn more… | top users | synonyms

0
votes
0answers
48 views

Incorporating sophisticated constraints on the approximating function into NMinimize

Following the approach as given in the answer of Belisarius here I just wonder how one could incorporate some more sophisticated requirements on the approximating function. Suppose the approximating ...
0
votes
0answers
40 views

Could not access a specific element of ConstantArray, why ? partw error [duplicate]

I could not access a specific element of ConstantArray, why ? The following is piece of my code: ...
0
votes
0answers
102 views

Best practices, tools, and snippets for manipulating notebooks, cells, packages, and help access? [duplicate]

Where is the best place to find/submit lists of Wolfram Language/Mathematica best practices, idioms, and patterns, perhaps grouped by topics? I'm personally interested in those that involve using ...
0
votes
0answers
49 views

system.dllnotfoundexception unable to load DLL“ .dll”: can not find corresponding module

There are two computers. One of them works correctly, whereas the second one writes an error system.dllnotfoundexception unable to load DLL" .dll": can not find corresponding module in Wolfream....
0
votes
0answers
53 views

Get Domain resp. implicit piecewise definition of numeric Function

Given the following quintic polynomial ...
0
votes
0answers
131 views

Extract frames as image files from video files [duplicate]

I have a set of video files where the frame rate is 1 frame/sec and the file shows the evolution of a particular object with time. Now, I want to extract each frame of the video and analyze as ...
0
votes
0answers
101 views

Fun/Frustration With Coding Coding Theory

I have code following from this post: http://math.stackexchange.com/questions/1317722/fun-frustration-with-coding-coding-theory I think I am done with the code, but now I face a single problem. The ...
0
votes
0answers
117 views

Evaluate notebook using text-based interface

I am trying to evaluate a notebook using a text based interface so that it can be submitted to a computing cluster. I have seen this stackexchange page and attempted to use ...
0
votes
0answers
41 views

$MessageList inside and outside Block[]

Why does 1/0 $MessageList return ComplexInfinity whereas ...
0
votes
0answers
63 views

Trying to write a program to find an approximate harmonic function on a given graph using relation method

So given an undirected graph with two vertices that have fixed values assigned to them, a harmonic function is a function that assigns values to all other vertices such that the value assigned to each ...
0
votes
0answers
25 views

Iterating a model with 2nd order difference equations using Manipulate [duplicate]

I have a model including first and second order difference equations. It works for the case of first difference equation, which is below: ...
0
votes
1answer
238 views

NDSolve with initial condition: initial conditions did not evaluate to an array of numbers of depth 1(for 1D) or 2 (for 2D) on spatial grid

I have the following naive code to solve a PDE in two spatial dimensions (x,y) with periodic boundary conditions: ...
0
votes
0answers
80 views

Define column types in a Dataset - Failure on append and Typesystem

I have a basic function that populates a Dataset according to user specified parameters. ...
0
votes
0answers
12 views

all does not work [duplicate]

Thanks blochwave for giving me a detailed answer, but I have already used all these methods and none of them has worked well, it is clearly written in mathematica "get help" file that the Timing[] and ...
0
votes
1answer
88 views

How can I use manipulate on multiple lists within a function?

So I have my N-Body Problem set up like so, and I can plot it in ListPointPlot3D, but I cannot figure out how to stick this into a manipulate function. ...
0
votes
0answers
104 views

Best practices for breaking up functional blocks?

Say I have a main function that does some job, and I'm only interested in the final result of ans, i.e., the local functions are not important and produce no side-...
0
votes
0answers
47 views

Find the maximum/ minimum of the function f(x,y,z) = x+2y+3z on the curve of intersection of the plane x-y+z = 1 and the cylinder x^2+y^2 = 1 [duplicate]

How to write the program for: Find the maximum/ minimum of the function f(x,y,z) = x+2y+3z on the curve of intersection of the plane ...
0
votes
0answers
26 views

A question about conditional replacement [duplicate]

{g[x, y, z], h[x, y], f[]} /. (f_[t___] /; f != List) :> Plus[t] Why is the output of this expression ...
0
votes
0answers
81 views

What is the meaning of //N in mathematica? [duplicate]

As the title says, What is the meaning of //N? i can't remember it.I tried looking in documentaion center, but it came up with nothing. Help appreciated.
0
votes
0answers
104 views

How do I perform the following numerical integration [duplicate]

I have the following integral to evaluate numerically: $$x(t) = \frac{1}{f(t)}\int_0^{t_b} t^m (t + n)^o \sin(pt) \mathrm{d}t \quad m,n,o,p \in \mathbb{R}$$ ...
0
votes
0answers
86 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 ...
0
votes
0answers
51 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 ...
0
votes
0answers
39 views

Can the value of a variable be made to persist between front end sessions? [duplicate]

For example, say I create a notebook with a cell a = 5 + 2 and then I close Mathematica, reopen the notebook, enter a new cell ...
0
votes
0answers
74 views

What is a good alternative to this numerical example taken from FindFit?

I am using MMA V9.0 What do you suggest for this numerical example? I am not getting good results trying to use my own procedure to find a "best" fit using the 1-norm. The 1-norm example for ...
0
votes
1answer
2k views

How can I draw this particular phase diagram in Mathematica? [duplicate]

Sketch the phase diagram for systems with the following velocity functions where a and b are constants with ...
0
votes
0answers
45 views

Generating partitions of a set with a specified size of the parts [duplicate]

I tried the following (inspired by the answer here) myList = {a, b, c}; Needs["Combinatorica`"]; SetPartitions[myList] and I got this answer, ...
0
votes
0answers
23 views

Conflict among Permutations and Graph utilities once Combinatorica is loaded [duplicate]

I have tried to figure out and solve the problem of compatibility of Permutations and Graph utilities of Mathematica once the Combinatorica Package is loaded, but I failed :(. Could anyone explain me ...
0
votes
1answer
2k views

Loops and subroutines [duplicate]

Possible Duplicate: Alternatives to procedural loops and iterating over lists in Mathematica I am new to Mathematica and not familiar with functional programming. In particular, I have no idea ...
-1
votes
1answer
148 views

Trying to write my own Greedy/ Nearest Neighbor Algorithm

So I'm trying to write my own function and compare it to the results I have from using FindShortestTour. Does anyone know how to find the distance from each city to each of the others without ...
-1
votes
1answer
123 views

Transformation of a simple logic statement

I'm designing a logic circuit and I was wondering if the following two things are equivalent: (x <= y) and (x < (y + 1)) I can't think of any set of numbers that would make these two things ...
-2
votes
4answers
655 views

Compare elements in a list

Assume that there are three different points in x-y coordinate like: p1={4, -1}; p2={5, -2}; p3={1, 5}; In order to compare these points to each other in a ...
-2
votes
1answer
299 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 ...
-2
votes
0answers
54 views
-4
votes
1answer
128 views

Programming Multipolar Expansions in Spherical Tensors

We have that a density matrix can be written in a basis of spherical tensors: $\rho =\sum _{K=0}^S\sum_{q=-K}^K \rho _{\text{Kq}}^{(S)} T_{\text{Kq}}^{(S)}$ for example for a 3x3 matrix, $S=1$, ...
-4
votes
0answers
44 views

How to add new formula in existing formula in certain time?

Good day, May anyone help me to give an idea to edit the coding For as below towards my problems. ...
-6
votes
2answers
74 views

Develop a loop with two counters [closed]

Description: I am trying to develop a function that would take two arguments n and m and would run another function multiple ...
-7
votes
1answer
83 views

My program to model exterior ballistics doesn't doesn't produce the plot I expect

Here is my program to model exterior ballistics. It doesn't doesn't produce the plot I expect. How can I fix it? ...