For questions on writing functions (pure or using Set/SetDelayed) for any purpose, including the features that may be incorporated in those functions, such as options, patterns and conditions.

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1answer
92 views

Why is Return not forcing an exit from my function? [duplicate]

Here is simplified version of my code that exhibits the behavior troubling me: ...
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0answers
47 views

A more efficient way of fitting a non-linear model that returns an entire list?

I have a function that takes two parameters, del and nu, and returns a list npoints long ...
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0answers
71 views

How can I add options to functions [closed]

One wish take easy advantage of the packages/codes buildt through our engagement with mathematica. Through building packages I see that I have made several functions which are simple and closely ...
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0answers
26 views

Minimizing roots of a transcendental equations [duplicate]

I'm trying to use the solution of FindRoot with parameters for further calculations. Annoyingly enough it always gives me trouble with replacing the parameters. As an example I'm attaching a simple ...
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0answers
66 views

Function behavior based on Head

I'm figuring how to implement a function behavior based on the Head of its argument. I mean ...
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1answer
252 views

Gram Schmidt inner and outer products

I know the Gram-Schmidt orthogonalization generates an orthonormal basis from an arbitrary basis. I need help with: Write a program that inputs a list $\{b_1,\dotsc,b_n\}$ of linearly independent ...
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0answers
40 views

Get pattern from rising numbers [duplicate]

I am no mathematician or math star, yet wondering if there is a formula or a way to calculate what follows: I have series of numbers: ...
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0answers
161 views

Issue with Coefficient command

I'm trying to used the Coefficient command to extract the numerical values in front of a Chebyshev polynomial. I know that there is a numerical way to do this, presented in numerical recipes, which I ...
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0answers
201 views

Positive integrand giving negative answer

I'm integrating a positive function f(t) times sin(t) from 0 to pi/5 and get -38. Actually f is slightly negative for a short time (smallest value ~ -0.0005), but far from enough to explain this. ...
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2answers
396 views

Collatz Tool Box — any speed ups possible?

I have created a tool box for experimenting with the Collatz conjecture. Info here: Wolfram MathWorld and here: Wikipedia The patterns I have found allow us to make the conjecture jump through some ...
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0answers
100 views

How to insert a function into OptionsPattern?

I’ve written a function TableauForm to draw a standard Young Tableau. This problem is related to this one, however, the difficulty is that, a function has to be applied to the list in my case. This ...
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0answers
78 views

How can I compile function with Apply?

For example, I tried to compile this function but Mathematica gives "The only function arguments supported are Times, Plus, or List", I have no a way to compile this. ...
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0answers
45 views

Using anonymous functions instead of module or block. Bad idea? [duplicate]

Here is an example function which returns True if a point p is on an (open) line segment (A, B) assuming that Orientation[A, p, B] returns 0 if the three points are collinear: ...
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0answers
259 views

Return Functions from parallel execution of module

I wrote a module which numerically solves an ODE using NDSolve. The result from this is e.g. either ...
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0answers
86 views

Non Commutative Multiply [duplicate]

Possible Duplicate: Non-commutative symbolic linear algebra I want to multiply two matrices, for example, A = {{e, f}, {g, h}} B = {{a, b}, {c, d}} ...
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2answers
940 views

Why function cannot be defined inside For loop? [closed]

I have a following code (which is simplified version of what I am doing): For[i = 1, i <= 5, i++, f[x_] := Sin[x]^2 Print[{i, f[i]}] ] And the question ...
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1answer
173 views

Please explain this code (contains Append, Do, Coefficient)

I am a graduate student using a past student's Mathematica program. Will someone please explain to me exactly what this piece of code is doing? Specifically the ...
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3answers
101 views

Using “With” outside a function on its parameters [duplicate]

I am making complex 3d graphics, and to clear up functions, I want to use With to remove a repeated action. This action occurs many times through many functions, so ...
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2answers
135 views

Defining a function as a sum of several Gaussians

I have a function that is a summation of several Gaussians. Working with a 1D Gaussian here, there are 3 variables for each Gaussian: A, ...
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2answers
59 views

Define functions from two lists

I have two lists {G[x_,y_],F[x_,y_],C[x_,y_]} and {x*y-x, 3x+y, x^y} Now I need to define 3 functions ...
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3answers
149 views

How to combine multiple functions into a single function, indexed bya new argument

I have a system of expressions (matrices) which correspond to increasing orders of precision in a theory. These expressions are quite complex (require about 40+ lines of code to produce) and are not ...
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1answer
172 views

A function generating particle-in-a-box eigenfunctions

The function sequence is defined over $[-\frac{L}{2},\frac{L}{2}]$ (all elements are valued 0 outside this interval): $$\psi_n(x)=\begin{cases}\sqrt{2/L}\sin{(\frac{n\pi x}{L})} & n \space even ...
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1answer
121 views

Logic behind Flatten and Append to in Module

I have a list(kicks), and a function(fix). I am aware of the problem using Loop and Append or AppendTo. My question is why does the Flatten produce the desired output. List: ...
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2answers
206 views

Constraining two points, a specified distance apart, to a line

Suppose that I have two points in the xy plane: pt1 and pt2init. pt1 is fixed in space, ...
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2answers
47 views

Defining a function from a list [closed]

I have a list of 49 numbers, and I would like to define a function f such that f(n) is simply the nth number in the list. How can I do this?
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1answer
79 views

Determining whether or not an expression is an integer

I'd like to define a function that controls if a certain number is an integer, rational, algebraic and so far. First, I tried generating a list of those numbers: ...
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3answers
154 views

Clean-up Code / Reduce variables

I'm writing a playing card simulator of sorts, and everything works fine, but some Modules use a disgusting amount of variables. For Example: ...
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2answers
93 views

Elegant way to transform formula with sum into code

I have this formula, and many other which contains sum, I am perfectly able to do the computation over a list, however to do this I need to do it in several manual steps. Therefore, I wonder if there ...
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1answer
98 views

Function giving negative value when it should be positive [closed]

I am trying to evaluate $$\displaystyle J=A\sum_{k=0}^{n-2}(-1)^k{n-2 \choose k}B^{n-2-k}\left(\frac{C_1}{k+n}-\frac{C_2}{k+n+1}+\frac{C_3}{k+n+2}-\frac{2}{k+n+3}\right)$$ in Mathematica as a function ...
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1answer
135 views

Optimizing Chi-square distance between two distribution

I want to program the chi-square between two distribution Xu and Vu with length N. This function is defined as below: Xu and Vu are real and positive. ...
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1answer
86 views

Defining the function of list of parameters

I'm defining the functions in the following way ...
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1answer
113 views

Normalize equation in NDSolve?

I have numerically solved and plotted the solution to the Mathieu equation using NDSolve successfully, as below: ...
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1answer
142 views

Patterns of function-arguments in expressions

I want a function that compares an expression with a specific pattern. The expression has always the following form: ...
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1answer
240 views

How to define a function with different types of arguments by setting conditions on function's domain?

I need help in order to properly define a function of $4$ variables. Given that: ...
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1answer
322 views

Function to marginalize a table over given parameters

Let us say I have generated a table tab with entries {p1,..,pd,chi2[p1,..,pd]} of dimension ...
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1answer
66 views

Have the kernel load a user-defined function by default [duplicate]

I wrote a very simple function that I would like to act as if it were one of the default functions that came with Mathematica, so that you don't have to load or import any package before you make use ...
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1answer
84 views

Given a sequence of expressions, how can I convert them all into functions?

I have a sequence of expressions 1, x, x^2, ..., x^5 I want to define a sequence of functions out of it, what should I do? Namely I want to define a vector of ...
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2answers
47 views

how to define roots of an equation as a function? [closed]

I need to solve an equation depending on 3variables in only one variables and define the roots as a function of the remaining variables? I used some thing like that: ...
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2answers
131 views

How to assign special colors to the output of DensityPlot?

I have created the following function for plotting ...
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1answer
148 views

Change input variable in a function [duplicate]

I'd like to write a function, that would take a matrix as an input parameter and would change it by multiplying one of its rows by a factor. I try to do it in the following way: ...
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1answer
146 views

iterative programming

i have 3 equations with 3 variables and two constants(to be substituted repeatedly). the value of the variables we got by applying nsolve on the system of 3 equations assuming some initial value for ...
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1answer
117 views

Multiple Simulations of a Markov Chain

I am trying to create a simple series of Bernoulli bits whose probabilities follow a two-state Markov chain. ...
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2answers
290 views

How to insert trigonometric functions into matrices' vector components? [closed]

Is it possible to insert a trigonometric function into a matrix which will be able to be used dynamically, as an element of one of the vectors of the matrix? I'm trying to perform an operation like ...
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1answer
61 views

Function that displays set of integers fulfilling constrictions

I would like to make a function of three parameters $i$, $j$ and $k$ that displays a list of integers fulfilling some criteria. Specifically the set of integers is: $\zeta_{ijk} = ...
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1answer
250 views

Creating Recursive Sequences

Quite a simple question, I reckon, however, even quite an extensive search hasn't helped me. I want to define a recursively defined sequence that starts with defined ...
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1answer
53 views

Creating a symbolic function dynamically given an array of data

I have a function that is based on the numeric values of a random sample that I would like to maximize: ...
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2answers
38 views

Custom function call does not return a value

I have written the following code to implement a PCA algorithm. It works on standalone basis, however when I put it into a function that is called the following ...
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1answer
70 views
0
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1answer
54 views

Output a symbol from Module or Block

I have troubles to output an entire symbol, a function in this case, from a module or a block. For instance myf = Block[{f}, f[3] = 33; f[4] = 4; f] Then I want ...
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1answer
88 views

Defining a function that differentiates another function with rule replacement

This question is related to the question I posted here. In that question, I thought I have simplified my original problem into an equivalent concise version, but I found that it is not. So I decided ...