Questions tagged [function-construction]
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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Building A Function Using Constants From a List
I want to build a function of the form
$f(t)= C + \sum_i A_i*Sin(f_i*t+\phi_i)$
Where $(A_i,f_i,\phi_i)$ are amplitudes, frequencies and phases that I have stored in a text file. Here is my attempt:
<...
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How to gather functions which intersect at the same point?
How to gather functions which intersect at the same point (real solution)?
func = {2 x, x^2 + 1, (x^3 + 3)/2};
For example, with the list of functions above I ...
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Using the Apply construction
I am puzzled about the use of Apply (@@). Consider
g = t;
g1 = Function @@ {t, g}
g2 = Function[t, g]
Why does g2 differ from g1? I had thought they would be ...
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Function defined through conditional pattern and derivative
If I define a function through a conditional pattern, its derivative is not defined in the whole domain of the original function...
Minimal code to reproduce : for instance, I define
...
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How to delete edges from a graph with some condition?
I want to delete an edge and its reversed edge from a graph (if they exist in the graph).
It would be OK to use EdgeDelete[g, {edge, Reverse[edge]}] if these two ...
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Sort a list using a scoring list with Switch [duplicate]
I have a minimal working example (MWE) list called listToSort that is a list of string triplets:
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Define a function on a MeshRegion
This looks like a simple question with the answer to be easily found, but unfortunately I could not find it either on the web or in the documentation browser.
Let us assume we have a MeshRegion ...
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How can I ignore an argument?
I made some code (attached below). It is meant to make a list of random numbers that is not divisible by some value k.
I wish to be able to not enter a value k, and have the code run regardless. It ...
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How to make a function take another function as an input?
I am quite new to mathematica, and I simply want to know how to make a custom function, take another arbitrary function as an input.
I have attached code that shows what I am trying to accomplish (...
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Automating interesting ways to write 2023
Inspired by Interesting ways to write 2023, I was wondering if there are ways to automate the search for results using MMA.
I tried
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Failing to define a function? [duplicate]
I am trying to define a function and it apparently is not working. Here is my small working example:
...
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1
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67
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Create a function that can assign values to different variables in Mathematica
Here I am trying to create a function that can assign values to different variables in Mathematica.
Assume the function
f[a _, b _, c _];
x1 = a;
x2 = b;
x3 = c;
...
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3
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Constructing a function that returns two distinct values by Mathematica
I'm trying to enter a function in Mathematica that can take two inputs, a, and b, and return two outcomes based on those two numbers.
I will assume the name of this function as
Resultsf[a _,b _]
the ...
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Is it possible to combine a default value in a function definition with type-checking, in case the optional parameter is actually given in a call?
1.) In a function definition, e.g.
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Piecewise function with form determined by current value
I would like to create a piecewise function that determines the dynamics of a variable $x_t$ as follows:
Given a starting value $x_0$ and a parameter $\hat{x}$:
...
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How does one pass an arbitrary expression (or expressions) to a function to later be evaluated? [closed]
This isn't my exact use case, but I think the answer will still be applicable to what I'm doing. I essentially want to create a function with which I can pass an expression (or list thereof), certain ...
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Returning an InterpolatingFunction
I am trying to write a function using Block that generates an InterpolatingFunction and then generates a second InterpolatingFunction that is a function of the first. I can return and use the first ...
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How to have index of summation equal to all $n$-tuples $\left(b_i\right)_{i\le n}$ with $\sum ib_i = n$ and $b_j$ fixed?
Let $T_n$ denote the set of $n$-tuples $\left(b_1, \ldots, b_n \right)$ of non-negative integers such that $$\sum_{i=1}^{n}ib_i=n.$$ I am trying to simplify the sum (whose indicies depend solely on $n,...
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How to do a 5x5 system using Cramer's rule? [closed]
I need to know how to do a 5x5 system using Cramer's rule.
1
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1
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131
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A square board of size n*n [closed]
I would like to Randomly generate n^2 natural numbers in an interval from 1 to n. Then consider placing each number on the cell with the same number (you can imagine the board numbered naturally, row ...
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Is there analogy of function MapIndexed (Map) for Nest?
We have Map and its upgraded variant MapIndexed.
Is there analogy for Nest? I know there is ...
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How to assign a variable in mathematica to just the output of an expression?
So, say I wanted to assign a function J[x_, y_] :={D[system, x], D[system, y]}//Transpose where system is some system of ...
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answer
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Print out how many times to calculate the sum of the squares of its digits until answer is 1 or 4
I am trying to write a recursive function, toscare1[], that takes as parameter a positive natural number. Then calculate the sum of the squares of its digits, thus creating a new number; then, we ...
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Derive a function and then make a fast version for execution
I would like to derive a (complicated) equation of motion and integrate it efficiently numerically. I can do this "by hand" by copying the resulting function in a new function and then ...
- 213
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58
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Kronecker Product for arbitrary number of spins
I want to write a function that can perform the following kronecker product:
...
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Generating a 3 variables polynomial with constraints on 2
This post is a follow-up of Generating a 2 variables polynomial with constraints.
I would like to generate automatically a polynomial in three variables $(s,t,u)$ which is symmetric under the exchange ...
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1
answer
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Generating a 2 variables polynomial with constraints
I would like to generate automatically a polynomial in two variables $(s,t)$ which is symmetric under the exchange of those variables. There are three kinds of terms; at order $k$, we have
$$(s+t)^k, \...
0
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1
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66
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Why did this code break on me? [closed]
Code was executing normally till I got an error message
"Tag Times in (x\ Sin[4\ x])[x_] is Protected."
...
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1
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151
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Using Reap Sow to define unsorted union [closed]
In the documentation of Reap under "Applications" paragraph there is this example:
...
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1
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Antiderivative of a piecewise function evaluates wrong inside a subroutine
It's very helpfull to use antiderivative of a given function in the form Derivative[-1][fun][t]!
Here my example with a simple piecewise function:
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A workaround needed to overcome the Derivative function anomaly in Mathematica 13
Edits:
Additional illustrations are provided for comparison with D[] in Mathematica 12, as clarifying examples, supplemented at the end.
An erroneous Derivative ...
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How to create all possible graphs that connect all vertices?
How can I generate all labelled connected simple graphs on n vertices?
In the image below, I drew examples with number of vertices ...
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1
answer
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How to evaluate this InverseFunction?
Solving an ODE problem
DSolve[{y'[x] == x*(y[x]^2 - 1)^(2/3), y[1] == 3/2}, y[x], x]
...
2
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4
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Quick and efficient way to create graphs from a list of list
I want to generate a list of edges from a list:
(the size of the list can be changed, just 4 for this example)
From the list above, I can generate 24 permutations like this.
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0
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What's the cleanest way to Plot a derivative, or ignore an outer scope in general? [closed]
As the title says, what's the cleanest way to plot a function's derivative in Mathematica? The two best methods I could find were either to define the function beforehand and then use prime notation, ...
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How to plot electrical graph from given edges with some constraints?
I'm trying to create a graph like this automatically with edges given and need some help. The graph doesn't need to be exactly same but I would like to make some constraints for the generated graph.
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How to add customized symbols between nodes without affecting the graph?
Is it possible to add some customized symbols between nodes (just for presentation) without affecting the graph?
This is an example where I added symbols of resistor, capacitor, and inductor between ...
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votes
2
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Function to create a connection list
Let assume that i have a list of connections between nodes like this:
input = {1 <-> 10, 2 <-> 3, 4 <-> 5, 6 <-> 7, 8 <-> 9};
The ...
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I want Mathematica to evaluate $\int(1 + \delta (x - \text {x0})) p[x] dx$ as $p[x0]+\int p[x] dx$, where $p[x]$ remains unspecified
I define the simple function:
Simp[h_] := Integrate[h[x] p[x], {x, -∞, ∞}]
where the function p[x] is continuous, but I want ...
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Can a pure function be constructed whose argument list is a matrix?
Can a pure function be constructed whose argument list is a matrix?
Using Function, I know it's not possible, but I'd like to get something like:
...
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1
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Default value for function inputs - Not allowing use of one input to define another
I am trying to define a function with a lot of input variables, and some of the inputs are used to define other input variables. If I define them outside of the function and then pass them in I don't ...
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1
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How to define functions using $Z_2$ coefficients and $Z_N$ variables, e.g, realizing $1+1=0$?
A minimal example is to realize the following:
$x+x = (1+1)x = 0$, and $x^{N+1}y^{N+1}=xy$,
where $N$ is a given positive integer.
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Mathematica function defining problem
The "F" function is defined as mentioned, but when I call the function F inside the code, "F" can't compute value using the function F, just give F_0, F_1, etc. Can somebody guide ...
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How to double sum or triple sum up over the list of functions?
I'm dealing with a summation problem by now using a list of function $F(x; \theta_i)$. The function is defined as
\begin{align*}
F(x; \theta) = 1 - \Phi[\Phi^{-1}(1 - \frac{x}{2}) - \theta] + \Phi[-\...
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51
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Simulate a binomial distribution experiment
I am trying to write a user-defined function to simulate a binomial experiment as following:
...
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How to create this function? [closed]
Let vowels:= {"A","E","I","O","U"}
Let alphabet be some CharacterRange, i.e.:
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