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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1answer
202 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
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 ...
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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: ...
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2answers
306 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
609 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
263 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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1answer
44 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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2answers
72 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
143 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
203 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
863 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
146 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
99 views
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1answer
243 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
226 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
672 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
221 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
189 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
222 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
42 views
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2answers
84 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
291 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
210 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
264 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
205 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
107 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
256 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
235 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
79 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
36 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
53 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
100 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
52 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
87 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 ...
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1answer
58 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 ...
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2answers
105 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 ...
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1answer
138 views

Read expression from Mathematica via Mathlink C++

This is a simple C++ program to send an expression to the_Mathematica_ Kernel and get its response. ...
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1answer
66 views

MLEvaluate() Function Gives Error

I am trying to link my C++ program to Mathematica Kernel. I am trying to use the MLEvaluate() evaluate but I receive an error while compilation. My codes are as below: ...
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2answers
115 views

How to return matching sublists or empty list

How to return matching sublists or empty list m1 = {{1, 0.5}, {2, 0.4}, {3, 0.1}}; m2 = {{1, 0.5}, {0, 0.4}, {0, 0.1}}; Commonest[Join[m1, m2]] out: ...
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1answer
221 views

Making an animated simulation without procedural loops

I'm still new to Mathematica and this is the first time I've wanted to do something more complicated than plotting and changing parameters of mathematical functions. I want to make a simple ...
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1answer
148 views

How can I import sound from within a Manipulate expression?

I want to import sound from a file, record, and import sound. ...
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1answer
742 views

pointer like operations in mathematica and evaluation control

I would like to create a data structure of the type "header[pointer]" where pointer would point to a list. I will shown on an example how I'd like this to work, and where the problems are. ...
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2answers
206 views

Checking equality with ComplexInfinity and testing whether a function is (mathematically) undefined

This seems ridiculously basic, but I cannot find anywhere explaining how to do it. If you evaluate certain undefined functions like 1/0 or ...
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1answer
161 views

What is the new command for AffineMap?

AffineMap was present in Mathematica version 4. What is the equivalent command in the current version of Mathematica?
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1answer
109 views

Draw from HistogramDistribution with ParallelTable

I wanted to check something, but ran into troubles using HistogramDistribution in combination with ParallelTable. The code does the following: Compute a HistogramDistribution of some sample and use ...
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1answer
45 views

Emulating Case Pattern replacement

As most regular users, I have developed utility functions complementing the Wolfram language for frequent tasks. In particular, I have variations on Cases (see ...
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1answer
100 views

Perceptron: Do loop not returning a value

I am trying to write a function that finds a simple best fit line for some data (Perceptron algorithm). Sadly it returns no output at all. Here's the code below: ...