Questions tagged [functions]
Questions about the use of built-in Mathematica functions, including pure functions.
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Solve in solving equation system
I have the following problem:
I have a system of equations specifically consisting of 56 equations, with 34 coefficients to be determined, in simplified form:
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1
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Laplace Transform and Different Results
I have the following piecewise function and I take the Laplace Transform
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How to plot points on a graph curve under logarithmic coordinate axis
I am trying to draw a curve and set a special point based on the logarithmic abscissa, as shown in the following example. The function is 1/(1+(RCw)^2)^0.5.
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Trying to produce an exact number from function [closed]
I have a function defined as follows:
approx[n_] := n^(2n^2+1)*Exp[-n^2(Log(Log(n))+1)]*Sqrt[2Pi]/(Log(n))
I want it to produce a numerical value as output in ...
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Issue with FullSimplify in StirlingS2 definition
I have previously asked a question about a problem simplifying an expression in Mathematica. The solution was to expand the definition of StirlingS2.
This time, I ...
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Problem calculating mean of probability distribution
I have a discrete probability distribution where $P(X=x)=(Factorial[n]/(n^x))*StirlingS2[x-1,n-1]$. So, when trying to calculate its mean with the following property: $\mu = \sum_{i} x_i \cdot P(x_i)$,...
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How can I ask Mathematica to give the explicit real form of the given function?
In part of my calculations, I obtain this expression which contains the imaginary unit I but I expect that this expression might be real (from the comments below, ...
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Converting between currencies using a pair of currency codes
Mathematica can convert currencies using real time data:
CurrencyConvert[Quantity[13.25, "USDollars"], "Euros"]
which gives
€10.8
Can I do ...
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Why NDSolve does plot only the output? [closed]
I am trying to solve a differential equation numerically with NDSolve. The code is
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Substituting solution into an equation in a module
I have this model which gives me list as an output
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How to use || as a function name and apply it to calculate the equivalent resistance of parallel resistors as we typically write?
The equivalent resistance $ R_{eq}$ of $n$ resistors in parallel can be calculated from this:
Would it be possible to define a function to calculate the equivalent resistance of resistors with the ...
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How to check if there exist variables for which a function may be real?
I have a tough time in checking whether there exist any values of x and y (both real) for which the following pair of functions ...
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Reversing the order of function arguments by a replacement rule
I am facing an issue when I try to reverse the arguments of a function in a replacement rule.
Let me give an example :
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How can I simplify this out put?
Based on this answer, I tried to find the condition to function $y = \dfrac{a x+ b}{c x +d}$ where $ad \neq 0$ and $a d - b c \neq 0$ increasing on $(-d/c, +\infty)$. I tried
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Which functions use a given option?
I occasionally discover Options which look like they might be useful, if only I knew which functions used that option. Is there a resource that lists all the functions which use a given option? What ...
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How combine two DensityPlot3D in only one graph
I need to combine two DensityPlot3D in only one graph but the "Show" doesn't work for that.
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Given two functions, generate all nested applications of the functions to a given order
I have two functions $f$ and $g$. Given some order parameter $n$, I want to created all nested applications of $f$ and $g$ and save them in a list. For example, for order 1 we will have ...
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Troubles with BlankNullSequence in the case of multiplication
I have some trouble to use the triple underscore notation to use definitions with or without a term. Consider the following toy example
f[a___ x]:=1
{f[x],f[2x]}
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Finding an ellipse of minimum area that encloses a set of points
Is there a built-in function or set of functions in Mathematica that can take a set of points in the x-y plane and determine the ellipse of minimum area that contains all of the points? I am sure ...
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How to effectively substitute variables in xAct?
I am trying to find the gauge field equation by varying the Born-Infeld Action with the help of xact package. I use the following ...
- 2,233
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Automatically detecting the function directory
Consider I have a function in /home/../Mathematica/FuncDir/Function.wl directory. The function is dependent on some external files, which are in the ...
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3
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Tally elements in a list of matrices up to an overall sign
I have a list of matrices like the following one with 6 elements:
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Optimal way of defining sums-linear function [duplicate]
I asked on a previous post how to define a function which satisfies $f[x+y]=f[x]+f[y]$ and then define $f[x]$ on monomials. The problem with this is that it involves a lot of iterations when we ...
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Strange errors of exceeding RecursionLimit in a function with two arguments, one set delayed and one fixed
INTRODUCTION
Hi. I feel a bit embarrased asking this question as the answer may be staring me in the face and there are at least two other stackexchange articles related to it.
MINIMAL WORKING EXAMPLE
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Define a function on a single element but linear in sums
I have tried searching around but I couldn't find the solution to this very simple setup. I want to define a function $f(x)$, which should satisfy $f(x+y)=f(x)+f(y)$, and whose action I only want to ...
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Solve equation for one variable
I have the following two equations,
di - (39.18 (0.07 + 2.61 (de + di)^0.28) +
1891.93 (de - di)^0.218)/(0.0119 + 0.0626 (de + di)^0.28)=0
and
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How to find the argument dependance of an expression
Consider expressions such as
X := f[n[1]][n[3]] g[n[7], n[1923]]
I would like to construct a function that returns the list of $n$'s on which $X$ depends. I know ...
- 375
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Solving multivariable equation after setting partial derivative to zero
I have a real-valued function of four variables, namely $L[\phi, m0, m1, m2]$. I am interested in taking the partial derivative $\partial_{\phi}L$ thereof and setting the partial derivative to zero, ...
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How to generate non-duplicate list of tuples with integer elements {-2, 0, 2}?
How can I generate all possible non-duplicate eighttupleList where each element, $a_i$, can be an integer from the set {-2, 0, 2}?
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How to obtain all definitions in which a symbol appears?
My question is very similar to https://stackoverflow.com/questions/5840313/how-to-get-all-definitions-associated-with-other-symbols except I am looking to find all definitions in which a symbol ...
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How to improve code speed for the large datasets?
How can I improve the speed of this code? It runs okay but is quite slow for large datasets, for example, 5 million elements.
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How to stop mapping on true results for large lists?
Assuming I have a long list (real data with more than 100k elements). I have a function that I want to apply to the list, for example, EvenQ. I want the mapping to stop once the result for one element ...
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Assign a function to other function with the change of the variable
I want to define a function that contains other functions but with other variables. Is it possible?
For example, I would like to do something like this:
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How to make a secondary top frame for a function?
I want to make a plot with two x-axes, one on the bottom and another on the top, where the variables are different but the function is the same. For instance, let f = y(a,b). How can I have in the ...
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How to use code to solve the parity periodic accumulation problem?
Given that the function f(x) is an odd function with a domain of real numbers R, and it satisfies the condition f(1-x) = f(1+x). ...
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Differentiation of Parabolic Cylinder Functions and Hermite Polynomials w.r.t to Order
When I evaluated (ver. 12.3) parabolic functions below in the vanishing order limit: $u \rightarrow 0$, I got the following:
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Tell Mathematica that the output of a function is a List / Vector
I have a function (Piecewise) that returns a list, e.g.:
F[x_] := Piecewise[{{{x^2, x}, x < 0}, {{x, x^2}, x > 0}}, {0, 0}];
I would like to add another list ...
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How to set optional variables in Function?
When using Function, is it possible to set specific arguments to be optional? For instance, in
f = Function[{x, y}, x + y];
Can ...
- 4,693
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Peak Appearances in Plot Outputs from Optimization Routines
Dear fellow researchers and Mathematica enthusiasts,
I've been working on a computational physics problem and encountered an interesting issue regarding the appearance of peaks in my plots, which I ...
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2
answers
110
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Problem with defining a bivariate piecewise function
I want to define the following function in Mathematica in order to evaluate its partial derivative later,
$$C(u,v)= (1+\theta) uv + \theta(u+v-1) F(u+v-1)$$
$$F(a)= 1\quad \text{if} \quad a \ge 0 \...
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How does this code work?
I saw this thread and upvoted many answers there.
Below is the answer by kglr (not my most favorite answer there, but it looks fun).
I wonder if anyone could help ...
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3
votes
2
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Is there an issue with calls to WolframAlpha from Mathematica? [closed]
I was trying to use the step by step to get a solution to an integral, but it was failing, so I tried an even simpler example from the Wolfram documentation
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Definition of ResourceFunction["IntegrateByParts"]
Here we can see definition of ResourceFunction["RainbowText"].
The definition is quite obvious on the image (explicit open source).
We can get the ...
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How to calculate the exact range of the analytic interval x of the piecewise function?
Use:
Clear["Global`*"]
f[x_] = Piecewise[{{3^(x - 1), x <= 1}, {(2 - x)/(x - 1), x > 1}}]
f[f[x]] + 1/3 f[x] - 2 // PiecewiseExpand
Get the result:
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How to remove non-loop vertices in a graph?
How can I remove vertices from a graph that do not form a loop?
For example,
...
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1
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How do I replace certain parts of an expression [closed]
Let's say I have this expression
2w E^(I w a/ (v+c)) + 4 w^2 E^(I w a / (v-c))
I'd like to replace every instance of ...
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Circular function with arbitrary radius and center
I'm looking for an implementation in Mathematica of the generalized circular function $\text{circ}(x, y; R, c)$ of radius $R$ and centre $c=(c_1,c_2)$ such that
$$\text{circ}(x, y; R, c)=\begin{cases}...
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2
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Contour Plot - L-Shaped
I am trying to plot a contour with an L-shaped form. I started by illustrating the contour function (horizontal, orange) and adding a line (vertical, black).
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answer
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Find the Intersection Point of Two Complex Functions Using Complex3DPlot
I want to find the intersection point using ComplexPlot3D. I have a function call it $f(\lambda,k)$ ($k$ is fixed) such that at two particular values of $\lambda_{1,...
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How to indicate table continuation in the middle with torn edge paper effect or something similar
I have a long table that I want to include on a PowerPoint page. I intend to truncate some data in the middle to ensure it fits on one page. How can I achieve this while indicating that the table ...
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