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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2
votes
1answer
282 views

Can Mathematica help a theorem to be alive?

We are used to do limits by means of $\epsilon, \delta$. This is the first step an student encounters limits. Using $\epsilon$ and $\delta$ leads him to be familiar to Logic. I have taught limits and ...
2
votes
2answers
68 views

Need help updating an old Mathematica worksheet

I found a notebook that symbolically applies the multiple time scales method to any differential equations. I don't like just using other people's code so I am going through the author's work line by ...
2
votes
1answer
95 views

ControlType -> None Vs. Module inside Manipulate (i.e. making everything local)

I'm building a program on another one made available in the Wolfram Demonstration Project. I've noticed that in the original code (working flawlessly) many variables were made local inside the ...
2
votes
2answers
185 views

Solving a dynamic program via recursion

I'm trying to use recursion to solve a joint inventory/ dynamic pricing problem as in monahan, petruzzi and zhao 2004. I tried to solve for y[t] and ...
2
votes
1answer
152 views

Piecewise function with user-input interval

I would like define a function g[data,bins,x] which is a piecewise constant function taking value data[[i]] in the range ...
2
votes
1answer
72 views

Evaluate only one from a set of procedures

Let's say I've got a list of procedures: {Print[1];, Print[2];, Print[3];} And I want to only evaluate 3rd one: ...
2
votes
1answer
196 views

Differential operator involving permutations

I would like to construct an operator in Mathematica of the following form, $$D_i=\partial_i +\sum_{i \neq j}^n\frac{1}{x_i-x_j}p_{ij}, \quad i=1,...,n$$ where $p_{ij}$ is a (symmetric) permutation ...
2
votes
1answer
237 views

Optimal image quality using Rasterize Function

Based on previous posts about plotting two y axes on the same x axis, I wrote this function: ...
2
votes
1answer
129 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 ...
2
votes
0answers
91 views

How to efficiently find parts of a string with beginning and ending specified?

I'm trying to find specific URL addresses from a html document. The addresses can be found between the strings "href=\"" and "\" class=\"listing". The problem is not including strings like this: ...
2
votes
0answers
80 views

How can I do multiple (double) integral with periodic boundary conditions?

I am trying to do a simple double integral $\int_0^l \left[\int_0^l h^3 h_{xxx}dx\right]dx$ with periodic boundary conditions $h[0,\tau]=h[l,\tau]$ $h_x[0,\tau]=h_x[l,\tau]$ ...
2
votes
1answer
75 views

Using HoldFirst but not wishing to hold everything

I have a DynamicModule in which I go through some data analysis and keep or reject the results. Here is a toy example of what I am doing. ...
2
votes
0answers
139 views

Maximizing Large Multivariable Function over Region with Parameter Constraints

Brand new Mathematica user here. I have a complicated function to maximize, and thought I would try software like Mathematica instead of taking derivatives by hand. I found some Mathematica ...
2
votes
0answers
75 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; ...
2
votes
2answers
159 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
0answers
57 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 ...
2
votes
0answers
89 views

Benefits of using Intellij IDEA as Mathematica IDE? [duplicate]

I use Intellij IDEA for Java programming, but have not really considered it for Mathematica. I saw a video with a Wolfram programmer who was describing it as "essential" for him, but from what I could ...
2
votes
0answers
287 views

Lazy evaluation/loading of parts of an expression

Is it possible to have an expression x such that its elements are only evaluated when they are individually accessed, for example when evaluating statements like ...
2
votes
0answers
335 views

Forecasting future Stock Prices II

I intend to do the following: I want to forecast future stock price under the following assumptions: The stock price is governed by the stochastic differential equation: dS = μSdt + σSdWt whereas ...
2
votes
0answers
79 views

SetDelayed and avoiding function calls through memoization [duplicate]

I am fairly new to Mathematica. I am working my way through a number of books. I have been looking at the use of SetDelayed and want to confirm that my ...
2
votes
0answers
566 views

Why is Mathematica limiting the execution time of my calculation? [duplicate]

Is there a Front End option (or programming option) in Mathematica 9 that limits the amount of time that functions take to execute? I have a function (as part of a Mathematica Application) that shows ...
2
votes
0answers
117 views

Programming Mathematica - Introduction by Paul Wellin [duplicate]

Possible Duplicate: Where can I find examples of good Mathematica programming practice? Can anyone recommend a decent book on programming mathematica ? I came across this which looks to be ...
2
votes
0answers
154 views
1
vote
4answers
179 views

Efficient replacement of conditional nested Do over elements of a matrix

I have two matrices like these: m1=Table[Random[],{i,10},{j,10}] m2=Table[Random[],{i,10},{j,10}] I want to create a new matrix in which its main diagonal ...
1
vote
4answers
137 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 ...
1
vote
2answers
192 views

Making nice code: choosing one of several procedures

Happy new year mathematica gurus of stack exchange! As I see it one of the major obstacles in getting decent at programming mathematica is that, not only do you need to learn how certain commands ...
1
vote
3answers
355 views

Replace with position and order number

question conversion1 : Convert "[AA]AB[AA]BB[AA]B[AA]CCC" to "[A1A2]A3B1[A4A5]B2B3[A6A7]B4[A8A9]CCC" conversion2 : Convert ...
1
vote
3answers
1k views

Finding the square root of a random number with Newton's method, using While/Do/For loops?

I am trying to construct a program that will find the square root of a number, using Newton's method, which is $$x(n+1) = x_n- f(x) / f'(x_n)$$ The number, will be a random number, generated by: ...
1
vote
2answers
314 views

How can I find minimum and maximum of a region?

I have a regionplot like the following: ...
1
vote
1answer
188 views

Help in Bifurcation Diagram

My dears, I need to plot a bifurcation diagram for the following non-linear systems represented by the next Mathematica code ...
1
vote
3answers
205 views

How to replace identical positions in two different lists

Assume that I have two lists like : list1={1,2,3,4,5}; list2={a,b,c,d,e}; I want to replace some elements from list1 into ...
1
vote
3answers
188 views

How to update a list in a function in each iteration

There is a list with numbers 1 to 8 ( p1 ) and another list (j) which contains 4 numbers which shows different 4 positions of ...
1
vote
3answers
200 views

Using Outer with Compiled functions that accept more than 2 arguments

How does one use Outer with a compiled function that accepts 3 or more arguments. Alternatively, how does one create a compiled function with 3 or more arguments ...
1
vote
3answers
110 views

Creating a list of lists as a function of a list

I have a list of length n whose elements are all 1 and -1. For each -1 in the list i want to create a list with a -1 in the same spot and a 1 everywhere else. For example: A list like {-1, -1, 1} ...
1
vote
2answers
282 views

What's the best way to generate all the upper triangular matrix whose singular values are given?

For example, given $\lambda_1 = 1, \lambda_2 = 2, \lambda_3 = 3$, what's the best way to generate all the upper triangular matrix ($3\times 3$) whose singular values are $\lambda_i$? Note:Given a ...
1
vote
3answers
245 views

Minimize user defined function

I have a user defined function h[i_,j_] and I would like to find its minimum value over all integers $1 \leq i \leq 100$ and $1 \leq j \leq 100$ and $j \leq i$. I would just like Mathematica to try ...
1
vote
2answers
416 views

Select rows from table by keys

I am looking for a way to iteratively select all sublists with the same ID (my 1st column, residual columns are AbsoluteTime entries). First, I obtained the list of ...
1
vote
1answer
457 views

Equivalent of Python's “all” function in Mathematica

The Python function def isPrime(n): return all(n % i for i in xrange(2, n)) checks if a number is a prime number by using ...
1
vote
1answer
877 views

Iteration of a function

I have a function $f(x)=x^7+k$ I want to iterate $xn+1=g(xn)$, 50 times starting with $x0=1$ and keep the last 10 values I want to assign these values to a function ...
1
vote
2answers
91 views

How to find total distance covered when I have a list of GeoPositions?

So I have a list of GeoPositions and I need to find the distance covered in that order? I know I can find the distance from each city and then add them all up but I was wondering if there is any ...
1
vote
2answers
108 views

Expressions containing globally undefined symbols inside a function where they are defined

Consider the following code. f[a_,b_]:=x; Clear[a,b]; x=a+b; f[1,2] It returns a+b. However, from a certain viewpoint, one ...
1
vote
1answer
78 views

RandomVariate form a Specific Distribution with Restrictions

There are a lot of questions about generating random numbers form both uni-variate and bi-variate distributions. Mathematica has a lot of built in distributions for that purpose. However, I could not ...
1
vote
1answer
67 views

Can I use Switch with an inequality? [closed]

I'd like to have something like: Switch[x, 10, a = 3; b = 7, >10, a = 5; c = 6, _, a = 7; d = 12, b = 1]; I can't seem to get this to work.
1
vote
1answer
262 views

Millionaire quiz in mathematica

so here's the deal. I'm trying to write a millionare quiz in Mathematica. Now, this has been already done in other coding languages, specifically I've seen it done in C here: ...
1
vote
1answer
125 views

How determine The most possibility probable with programming

i have a scatter chart of probable of happen some thing like below chart link of google chart i what determine the probable The most point in below chart , can use a mathematic method to determine ...
1
vote
1answer
201 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 ...
1
vote
4answers
142 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
1answer
139 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 ...
1
vote
1answer
116 views

Requesting explanation of FitModel code

I am struggling with understanding the code given in this original post I understand how the tests are conducted, both of them. However, I do not understand this part: ...
1
vote
2answers
305 views

Doing vector manipulations on Mathematica

This is hopefully a simpler version of this previous unanswered question of mine. Let me just focus on the two expressions $F_2^{(s)}$ and $F_3^{(s)}$ given in A.3 and A.4 of page 19 of this paper. ...