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.
1
vote
4answers
91 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 ...
4
votes
2answers
124 views
Plotting: DensityPlot produces artifacts
I am trying to plot the electric potentials of bouncing balls using the following code:
...
0
votes
2answers
81 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:
...
6
votes
1answer
244 views
0
votes
0answers
63 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
47 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
107 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 ...
0
votes
2answers
79 views
1
vote
2answers
159 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
1answer
189 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 ...
0
votes
0answers
35 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
4answers
126 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 ...
1
vote
0answers
69 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
43 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 ...
0
votes
1answer
113 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 ...
5
votes
1answer
166 views
Higher RAM handling by 32bit Mathematica [closed]
Can 32 bit Mathematica run program which requires more than 4GB RAM ?
1
vote
2answers
78 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
105 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 ...
4
votes
4answers
545 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 ...
8
votes
1answer
97 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 ...
2
votes
0answers
44 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
74 views
0
votes
0answers
33 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
...
1
vote
0answers
110 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 ...
1
vote
0answers
85 views
Whats Mathematica exactly is? [closed]
Is it a software to learn mathematics and programing? Or what? Sorry for my ignorance and my English. I'm not clear about what is.
0
votes
1answer
71 views
0
votes
0answers
36 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 ...
13
votes
4answers
1k views
How to implement the Observer design pattern?
As a programmer with a history with procedural languages, the Observer design pattern inmediately springs to my mind when attacking certain class of problems, mostly UI/notifications related.
A ...
3
votes
1answer
118 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 ...
0
votes
1answer
88 views
Using Findroot within a loop
I am trying to get solution to an equation in a loop. The isolate equation works
...
2
votes
0answers
118 views
DynamicModule inconsistent behavior; was: DynamicModule persistent UI changes
Update:
I'll restate the question in hopefully more terse and clearer terms.
To illustrate the issue, run this and save the resulting notebook:
...
1
vote
4answers
112 views
How to count number of {True,True} outputs?
Do[Print[{x + y + z == 3, x + y > z}], {x, 1, 2, 1}, {y, 1, 2, 1}, {z, 1, 2, 1}]
If I run this syntax I get a series of Outputs, I am trying to Count only the ...
5
votes
3answers
215 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:
...
0
votes
0answers
66 views
How to save the results in an identical Excel file (.xls) in each iteration of a Do loop
Assume the following code (Below code is just an example to clearly illustrate my problem):
...
0
votes
0answers
90 views
Mean Squared Deviation for Population Data
I've been using the Lotka-Volterra equation to estimate population sizes and need to find the MAD (mean absolute deviation), MSD (mean squared deviation) and mape (mean absolute percentage error) for ...
9
votes
2answers
841 views
Is it possible to create iOS apps with Mathematica?
I am fairly new to Mathematica and don't have much experience with other programming languages, but I can already see that Mathematica and the Wolfram language are far easier to use than most others.
...
2
votes
0answers
48 views
What is “ (Dialog) Input [ ] := ” after evaluating a cell?
I have done a time-consuming run and calculation. After many hours ( about 7 hours!), the black color which shows that the cell is evaluating, turn into gray and a strange text appears like this :
...
1
vote
1answer
83 views
Scope of variables within a Manipulate expression [duplicate]
I have a problem in defining the local variables.
I have this code:
...
20
votes
4answers
912 views
Detecting patterns of black and white stones on a 2D board
I'm writing a program to play a game of Pente, and I'm struggling with the following question:
What's the best way to detect patterns on a two-dimensional board?
For example, in Pente a pair of ...
-1
votes
1answer
41 views
How to loop in reverse order?(e.g. for i from 10 to 1) [closed]
I have a list F = {382.856, 638.53, 915.482, 1192.44, 1469.39, 1746.34, 2023.29, 2181.91}
And I want to use it to calculate V:
I think it should be something ...
0
votes
0answers
88 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 ...
0
votes
0answers
73 views
A problem with functions and Infinite expression 1/0 encountering
Following code (function) makes integrals and then replace f[x] with Cos functions and calculate the definite parametric ...
0
votes
1answer
101 views
A problem with set values
The following code is just an example to clearly explain my problem.
Assume that :
...
0
votes
1answer
84 views
How to produce functions [closed]
I want to produce n functions. For example, assume that by giving n=3, 3 definite integrals will be created, like the following:
...
0
votes
1answer
116 views
Mathematica Implementation of Householder’s Method
I typed the Householder code in this paper, which starts on page 7.
The code is:
...
2
votes
0answers
52 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 ...
1
vote
1answer
102 views
Help to solve the equation with RungeKutta method [closed]
I need to solve this equation.
v'[t] + v[t] == 1/(1 + Exp[-v[t]])
I tried to solve it using RungeKutta method described in Wolfram ...
7
votes
1answer
91 views
Equivalence under common permutations
I have lists which consists of sublists of equal length. The outer list is regarded as a multiset (that is, permutations of the sublists don't matter, but repetitions do), but the order in the ...
0
votes
0answers
25 views
Does RuleDelayed work inside MessageName?
using : Mathematica 9.0.1.0
Hello !
Does RuleDelayed work inside MessageName ?
This code:
...
1
vote
1answer
110 views
How to replace a list with the result list after each iteration [closed]
I have some initial values such as L1 list:
L1={10,20,30,40,50};
I want to use the L1 ...
