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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203 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 ...
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3answers
111 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} ...
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2answers
299 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 ...
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3answers
257 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 ...
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2answers
427 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 ...
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1answer
463 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 ...
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1answer
899 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 ...
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2answers
92 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 ...
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2answers
112 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 ...
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1answer
81 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 ...
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1answer
140 views

Transform linear system into a matrix form

I have a system of linear equations in variables $A_n$ of form: $$ \sum _{k=-K}^K h_k A_{n-k} J_{n-k}\left(\frac{(1-i) \text{$\eta $Sqrt}(n-k)}{\sqrt{2}}\right)+A_n\left(\frac{(1-i) \eta ...
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1answer
270 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: ...
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1answer
128 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 ...
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1answer
208 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 ...
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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 ...
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1answer
117 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: ...
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2answers
310 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. ...
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2answers
619 views
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3answers
2k views

How to create functions of arbitrary number of variables? [duplicate]

In the following code what would be the simplest way to generalize it to say some $N_f$ number of $z$ instead of just $z_1$ and $z_2$? ...
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1answer
265 views

Code to draw geometry doesn't run

I'm new to Mathematica and have no background whatsoever in programming, although I will teach myself soon. I was wondering if one of you programming pros could help me out. I received a code from ...
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2answers
78 views

Ask about the variable and constants in partial derivative in a loop

EDITED I have a function in a list like : func={2(x^2)+x*y+3(y^2)}; I want to have a UI that ask me which parameter (x or y) is a variable in a ...
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1answer
47 views

Is it possible to use FormObjects and FormFunction in a stand-alone notebook?

I have been looking at the FormObject and FormFunction. Can FormObject and ...
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1answer
114 views

Fibonacci Line Search Method

I am attempting to write a code to find to bracket the minimum of a function using the Fibonacci Line Search Method, I believe my code is well written but I am not ...
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2answers
75 views

Subroutine execution repetition

I like to write second and third lines repeated operation only once as a separate module with some Name. In each main program line a set of different set boundary conditions data is given,Name invoked ...
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1answer
147 views

For loops in Mathematica [duplicate]

I'm actually the first time using loops in Mathematica. For example, I have: For[i = 1, i <= n, i++, For[j = 1, j <= n, j++, ....] How it is possible now ...
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2answers
208 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 $n=2$: ...
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1answer
901 views

Euler's method for system of differential equation

I need to program Euler's method to solve a system of two diffferential equations of first order. Fist, I have programmed the Euler's method for just one differential equation: ...
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2answers
150 views

How to automatically put the part of a variable name after the first letter in symbolized subscripts?

So here is what I have thought: Use ToString and StringLength in order to get the number of characters in the variable name. If it is bigger than one, change variable name by putting everything but ...
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1answer
100 views
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1answer
251 views

Pseudo-code for rules of probability?

I am having a hard time in Stats understanding some basic rules of probability and set-theory, namely $P(A|B)$, $P(A\ \textrm{and}\ B)$ and $P(A\ \textrm{or}\ B)$ where $A$ and $B$ depend on each ...
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1answer
239 views

Handling Overflow

I have a notebook which takes in a user-defined function and starting value and tracks the orbit of the particle under iteration of the function. The problem occurs when the user enters a starting ...
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1answer
722 views

How to run Mathematica using Mac Terminal

My question is so trivial and I'm sure most people in here know exactly how to do this, however I still don't know how to run Mathematica in Mac terminal! I need to use all the cores of my computer ...
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1answer
228 views

Automating sequential import of data from web

I am trying to import data from multiple web pages hosted by a single online source. The data is posted by the source as one data set per web page for each week of the year. I would like to import the ...
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1answer
190 views

How do I insert a piece of code in Mathematica?

In Fortran, I can use include "file" to insert a piece of code. Is there a similar method in Mathematica?
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1answer
225 views

How do I slice an image of size “width × height” in n² pieces of size “width / n × height / n”?

Background: What I want is to make a jigsaw from an image. (A simple one where the pieces are polygons.) I have the following strategy in mind. Create a set of polygons and assign images (or just the ...
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1answer
51 views
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2answers
91 views

How do you apply an algorithm individually to an array with many graphs

I have and array with many graphs to which I want to apply an algorithm (below) to each graph in an array that contains all my graphs. ...
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2answers
327 views

Plotting an orbit using first principles [duplicate]

I am fairly new to Mathematica, but I am trying to plot an orbit of the Earth around the sun using the equation: $\quad r(t+dt) = (2 - G*M*dt^2/r^3)*r(t) - r(t-dt)$ I need to break this into ...
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1answer
212 views

Programming- cryptography

I have defined the following function in Mathematica to get a SET OF m SETS (these sets are the codes {p,q,d,e,n} for the ...
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2answers
269 views

Plotting in the “Manipulate” function - simple coding

Hello Mathematica community, my name is Preston! I have a real quick question that should be easy to answer. Alright, so for a research project that I'm involved it at my university, I need to ...
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1answer
208 views

Calculating mean of multiple stochastic processes and setting a lower threshold

Thanks to “Rod Lm” I got some very nice input for the following problem. My intention is to simulate within a Manipulate function a given number of possible stock ...
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1answer
109 views

How can I find the row differences of a matrix?

How can I compute the row differences of an m x n matrix to obtain an m-1 x n matrix; that is, given how do I obtain
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2answers
261 views

Inputting two arrays for a module in Mathematica

I am relatively new to the Mathematica enviroment and not sure where I am going wrong. I have evaluated the question and understand it, but dont know how to exactly create a module for it. The ...
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1answer
236 views

How can Time be made to go backwards?

I would like to make a countdown timer, but cannot find a reliable method to make the DateList[] function reverse. The not so robust code for the Digital Clock with the display of seconds follows: ...
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1answer
43 views

Implicit region is not “valid” in ParamatricNDSolveValue function?

I am trying to solve a geometric problem with relation to my Schrodinger equation and its boundaries. Here is my code: ...
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1answer
60 views

Ways to protect certain parts of expressions

I am currently working on a quantum mechanics problem where I try to find equations that relate different states of a many-body system. The states are described by sets of pairs of integers, like ...
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1answer
114 views

How would I obtain a list of column names in a Dataset?

I really love the addition of Dataset to Mathematica. I would like to write a basic utility function that exports a Dataset to Excel. Is there a way to get a list of column names from a Dataset?
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2answers
56 views

How to get the outermost command evaluated first?

I have an expression like ToString[Stuff[...]]. I plan on having the Stuff[...] be manipulated as a string according to the output of other parts of the program. The problem is that Mathematica tries ...
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2answers
92 views

Using conditionals to check if LinearSolve found a solution

Is there some way to check if LinearSolve found a solution using conditionals in Mathematica 9? I need to solve a large number of linear equations, but I am only interested in the cases where there ...
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2answers
67 views

Changing a tag when one function is passed into another using UpValues

I have two complicated functions f[x,y] and g[t]. Before the main evaluation code in ...