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
31 views

Why would this function work only when I make a copy of the variable? [duplicate]

Why would this function work with a copy of the function variable: ...
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1answer
108 views

multiple generators for iterative construction of fractal

The code below is an attempt to use more than one generator (in this case two) to generate a fractal using the standard iterative procedure involving generators. Only the first two stages of the ...
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1answer
50 views

Assigning a given value if a function returns an error [duplicate]

This question has to do with error handling, I guess. I am using Brent's Method in order to numerically find the root of a function. This is just an example of what I am doing: ...
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1answer
57 views

Alternatives to indexed variables in Compile

According to the excellent answer given here by @Leonid Shifrin: How to compile effectively?, You can not really use indexed variables in Compile, although it ...
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1answer
51 views

Generating list of functions from list of expressions

I know how to create a function from concrete expression like Function[{x, y}, x^2 + y^2] But what if I have a list of expressions list1 and I know the set of ...
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1answer
87 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: ...
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1answer
87 views

Working with functions

I am required to write a function that takes a function as a parameter. ...
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1answer
45 views

Convert variable into function

Sorry if this is a duplicate, but I have a variable called H. H is some complicated function of ...
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1answer
63 views

Using Derivative with list in curly brackets

I'd like to make a formula for a sum containing Derivative where the number of arguments in the latter depends on an input parameter n. Also involved is a list ...
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2answers
182 views

Defining Piecewise Functions in Modules

In short, my question is the same as my previous one except that everything is now wrapped up in a module. The relevant code I'm working with is: ...
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1answer
109 views

Is it possible to define a function in terms of a power series?

Is it at all possible to define a function in Mathematica in terms of a power series? For a specific example, I wish to write $x(\tau)$ as $x(\tau)=x_{0}(\tau)+\mu ...
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2answers
116 views

A function that (also) changes a replacement rule

I'd like to write a function operating on a list, returning a list, but also changing a replacement rule. Let's say I have a list of replacement rules: ...
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1answer
64 views

Extracting function variables from a list [duplicate]

Evaluating the following func[x_, y_] := x^2 + y^2 listn = {{a, b}, {c, d}, {e, f}}; Map[func[##] &, listn, {1}] yields {func[{a, b}], func[{c, d}], ...
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1answer
133 views

Unable to import functions from external file

I'm fairly new to Mathematica but I'm in the process of setting up some basic analysis based off someone else's work. They had a number of shared functions stored in a shared code directory and were ...
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1answer
214 views

How could we define a function recursively?

Let us first consider the constructon of the following simple iteration ...
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1answer
105 views

Defining functions from expressions of variable lengths

I have a list of symbols that I have defined using d = Table[Symbol["d" <> ToString[i]], {i, 1, n}] giving ...
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1answer
131 views

Bad function evaluation

I am having some trouble with this function ...
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0answers
71 views

How to conveniently stop a programme without aborting the computation

I have a programme that will have to run for a few days. However, I would like the user to have the option of stopping the computation of the code, without aborting it, when he desires, without ...
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0answers
54 views

When to break large programmes into smaller programmes?

Say I have a main function ...
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0answers
44 views

Question about treillis structures

I have difficulties finding a command to plot multiple segments connected in nodes in Mathematica. Ultimately, my goal is to modelise something like this by entering nodes coordinates. Also, the ...
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0answers
41 views

Add constraints to a variable number of parameter in Minimize

i want to use Minimize with a variable number of Parameter which works fine: ...
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0answers
118 views

How to create a reliable natural integral operator? [duplicate]

Natural integral is one of the antiderivatives of a function, for which the integration conctant is fixed in a natural way. It is defined as follows: ...
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2answers
59 views

Eigenvectors inside a maniupulate function

I am trying to make a physics application and it requires that the eigenvectors be taken for a 3x3 matrix. It is my intention that Mathematica never have to deal with the matrices symbolically. ...
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0answers
58 views

How can I avoid a scoping problem when differentiating?

I simplify my real problem as follows: I define a rule function as Clear[rule]; rule[i_] := tt -> i; the real rule function is not this simple. I define a ...
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0answers
58 views

Maximum and mean of a multi-variate function over a restricted lattice

I have a function Q, and I want to find the maximum value, the corresponding arguments for the maximum value, and the mean over a certain range of arguments. I ...
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0answers
23 views

Coding contour integration [duplicate]

I am struggling to understand contour integration. How would it be applied in Mathematica? I am hoping that if I see it written in Mathematica code, it will help me understand it. eg how would ...
0
votes
1answer
60 views

Defining arbitrary order derivatives function [duplicate]

I have a function $\phi(t)$ and I want to define a function $\phi D(t,r):=\phi^{(r)}(t)$, in other words evaluate the $r$'th derivative of $\phi$ at $t$. The naive code that I have is: ...
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0answers
84 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): ...
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1answer
90 views

Define a function that takes ragged array [closed]

newbie here. I want to define a function that takes a ragged array and return another one, but how. Say, I want to define a simple function behaves like this ...
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0answers
165 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 ...
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0answers
78 views

How can I use a For loop in a recursive function?

I am creating a simple radix2 FFT algorithm (based on Cooley-Turkey) by using a recursive function to obtain the fft. The function is supposed to work on a list (assuming the length is a power of ...
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0answers
41 views

Using Table[ ] vs using Do[Append [ ] ] [duplicate]

Is it generally better/faster to use the Table function over using Do[Append []]? For example, I have this piece of code: ...
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0answers
35 views

Varying number of function arguments [duplicate]

I have a function of six arguments: ffit[q1_, q2_, q3_, q4_, q5_, q6_] := (a1*q1^2 + a2*q2^2 + a3*q3^2 + a4*q4^2 + a5*q5^2 + a6*q6^2) ...
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0answers
76 views

creating some smooth density functions

I would like to create some density functions based on some distance measure $D$. As a base density function lets say I have a Gaussian density $f$ with mean $-1$ and variance $1$. I would like to ...
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votes
2answers
81 views

I want to define a function that has integer power [closed]

I am defining this function: f[x_] = kr*g[x] + (c^l*x^l)/(KIR + c^l*x^l) But I want to make l bigger than 0, so if I evaluate ...
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0answers
79 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
40 views

Nested For Loops that result in no output [duplicate]

I am sure that this is not the most elegant code you will have seen, but I am trying to loop through an expression to see if FultonHarrisn] produces any outputs ...
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0answers
53 views

Question regarding function definition overloading / argument passing test [duplicate]

It is possible to define function dependently to passed argument type or condition this argument fulfills (somewhat like overloading): ...
0
votes
1answer
116 views

Strange function definition result [duplicate]

I'm relatively new to Mathematica, and I'm trying to define a function f(k) that would do the following: For any positive integer $k$, a finite sequence $a_i$ of fractions $\frac{x_i}{y_i}$ is ...
-1
votes
1answer
1k views

How can I make a plot of the Higgs potential?

I was wondering, how would could I make a drawing of the Higgs potential aka "mexican hat potential". I am quite new to Mathematica and don't know where to look to learn how to implement such a ...
-1
votes
2answers
66 views

Plot not showing values

Still pretty new too Mathematica. Can someone please point out what im doing wrong when trying to plot the Dijkstra' s fusc function? code: ...
-1
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1answer
57 views

Creating new functions using the names of existing ones

I have a list of functions {G[x_, y_], F[x_, y_], C[x_, y_]} how I can create the list of new functions such as ...
-1
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1answer
74 views

How to specify a specific range for a loop?

I'm having trouble with setting up a particular range in a loop for my programming. Now I have a defined range of data (not continuous numbers) that needs to be applied in a loop. Since the aim for my ...
-1
votes
2answers
455 views

How can I define a function which is the sum of other functions?

I have a function which is summation of another function over different i,j iterators. U[r] = Sum[V[r, i, j], {i, 1, 5}, {j, 6, 10}] and ...
-1
votes
1answer
116 views

Dynamically show a specific number of the fractional part's digits

What is the fastest way to cut off all n z digits of the fractional part of a real number? (For example 12390.20934230) I came up with this so far: ...
-1
votes
1answer
413 views

Multivariate Function Approximation With a Large Dataset

I have a nice amount of data from a trading strategy I am working on, where I have two different liquidity parameters as x, y variables. Before entering a trade I am taking the moving average of ...
-1
votes
1answer
243 views

How to define a pure function with a Module?

I was not able to use a self defined (using Module and For loops) piecewise function to fit data. It seems that the problem is that I have to define a pure function. I would like to learn how to ...
-2
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1answer
89 views

Calculations in sequence

I have a this calculation, as you can see it is doing a calculation on each list, from list 1 to list 4 of the datafile. My problem is that using Mapthread to do this calculation does not work because ...
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2answers
241 views

How to correctly call a Module within another Module?

How to embed and call the correct embedded modules inside another Module? Say: ...
-4
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1answer
113 views

Programming Multipolar Expansions in Spherical Tensors

We have that a density matrix can be written in a basis of spherical tensors: $\rho =\sum _{K=0}^S\sum_{q=-K}^K \rho _{\text{Kq}}^{(S)} T_{\text{Kq}}^{(S)}$ for example for a 3x3 matrix, $S=1$, ...