Tagged Questions

Questions about the use of built-in Mathematica functions, including pure functions.

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How to use NestWhileList with a function of two variables

I want to iterate a function of two variables in NestWhileList. Obviously it will need a termination condition. For example imagine I have this function: ...
35 views

Help Compiling Vectors using Iterations

So I have a nice code that runs properly, which I include below but, in my naiveté, I'm having issues iterating my procedure. Simply put, I have a function of two real variables $f(x,y)$ and I want ...
67 views

Weird SeriesData behavior?

I was trying to calculate the determinant of a matrix whose elements are truncated series. As a result I obtained an expression like this: ...
34 views

How to find vertice by two angles and side? [migrated]

I know 'alpha', 'betta', length 'c', vertices: 'A' and 'B' How can i find the 'C'?
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Transform an expression into a function [on hold]

I have a matrix of the form Mat = {{2a, 7a},{5a, 3a},{a, 2a}} (the actual matrix is a hugely complicated one of size 64x64, but the idea is exactly the same). I ...
367 views

Distributing function arguments with function compositions. How to compute $(f + g^2)(x) = f(x) + g(x)^2$?

Suppose I have two functions f and g. To compute $f + g$ evaluated at a point $x$, I know that one can use ...
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Union sorting after ignoring some digits

I have a list with its bellow elements: {-0.7071067811865476, -0.7071067811865475, 0.7071067811865475, 0.7071067811865476} If I use ...
113 views

How to 3D-plot with specific ranges?

I have the following function which I want to plot using Plot3D: (-1 + w + 3 s w)/(2 (-1 + w + 4 s w)) , which is only ...
11k views

Calling Correct Function for Plotting DiracDelta

I am wondering what is the correct function in Mathematica to plot the true impulse function, better known as the DiracDelta[] function. When using this inside of a ...
574 views

Is the renaming mechanism of With flawed?

I'm confused about the renaming mechanism of With: ...
111 views

The implementation of FunctionRange

How exactly does the FunctionRange work? What kind of algorithm does it use? I looked it up in the manual but it doesn't provide any references or even a name of ...
149 views

What function superseded SpaceForm?

In older versions of Mathematica you could use SpaceForm to leave a certain amount of spaces when writing to a file. For example, if we have the following data: <...
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Passing each element of a list as an argument to a single parameter function [closed]

Consider a single parameter function: g[w_] := w^2 +1; Consider a list: slist= Range[0, 100, 1]; Now when I apply function ...
151 views

Check an inequality if one condition holds

A = Abs[-1 + 1/(1 + β)] + Abs[-((1 + 2 α + Sqrt[1 + 4 α + 4 α β])/(2 α + 2 α β))] Is A <1 if ...
34 views

Defining a variable inside a function to reference it in the function

I am trying to define a variable and use it inside a function. However, I am having troubles calling the variable. For instance, I define the function ...
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Watched a Livestream with Christopher Wolfram, he used an operator that I can't find [duplicate]

I understand /., /@, /; and documentation exists in the normal way for all of those but I can find nothing on /*
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Intercept in the ARProcess

In the ARProcess help file I don't understand whether an intercept is included or not. How would I add one? I am using version 9 of Mathematica.
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Reduce a complex inequality

Reduce[Abs[1/(1 + I/Sqrt[α])] < 0.5, {α}] It is taking long time to run. Can any one help me to get the reduced condition in terms of $\alpha$ or its modulus. ...
58 views

Mathematica Empty Plot FourierSinSeries function

I'm trying to get a plot of different order Fourier series of the function x-1, why does Mathematica give me an empty plot? ...
59 views

Why is FindRoot failing to evaluate this function? [closed]

I have a (somewhat long) script which runs cleanly until the very last stage. Here, I'm using FindRoot to attempt to parameterize implicit curves in the zero set ...
53 views

How to plot a level set of a function $f(x,y)$ on Plot3D?

Suppose I have used Plot3D command to plot some surface $f(x,y)$. On this plot, I would like to clearly identify some level set of $f(x,y)$, let's say $f(x,y)=0$, and if possible, find the relevant ...
84 views

How to define a function which takes another function as input in Module

Let $f$ be a function of $n$. I would like to define a function $A$ with module which takes $f[n]$ as input. So for example: ...
62 views

Mapping a simple 2 variable function

Quick Question: What is the best way to map this function so it performs seperately for 102 different values of x? ...
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Basic Question on function of $n$ when it shift to $n-1$ [duplicate]

This question is basic, but I do not know what is wrong. Clear[a0,a] a0=n; a[n_]:=a0 But when I evaluate a[n-1] the output ...
4k views

Nested If statements

When I do this: Apply[(If[#2 == what, "yay", If[#2 == whoops, "nay"]]) &, {-5, what}] I get: yay But when I do this: <...
134 views

Evaluating standard functions of general quaternions symbolically

Mathematica can easily compute exponentials and logarithms of concrete quaternions: ...
97 views

Analytic differential of an inverse transcendental function

I have the following function: $$y(x)=\frac{Ax}{Bx^{1/4}\sinh{(\frac{Bx^{1/4}}{2})}}\left(\cosh{(\frac{Bx^{1/4}}{2})}-1 \right),$$ where $A=112.941$ and $B=18.6588$. I want to find the differential ...
58 views

How do I get a 'list' (or something similar) of functions?

I'm solving an NDSolve equation, like: ...
62 views

Finding a maximum of a Bézier function

Suppose I have a Bézier function $f:\mathbb{R}^2\to\mathbb{R}$ with random coefficients: ...
59 views

How to draw a contour line that intersects with a specified line (perpendecular to xy plane)?

Assuming I have the 2D scalar field $f(x,y)$ and I want the contour line of $f$ that intersects with the line $x=2,y=3$. How can I do that? At further steps I want the equation for that contour line....
138 views

Integrate on a contour in the complex plane

I want to integrate the function f[z]= z + Conjugate[z] over a circle of radius 2 centered at the origin. For the sake of stating something that I have tried: <...
97 views

Find the equation of the parabola and sketch the graph [closed]

Consider the following information: A quadratic function with equation $f(x) = ax^2+ bx + c$ passes through three points, $A(-1,-1), B(1,-7)$ and $C(3,3)$.
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How do I get Series[] as a functional, rather than as an expression (i.e. to avoid the dummy variable)?

How can I write an equivalent to Series that doesn't require a dummy variable? Note that the series should be constructed before the evaluation point is supplied, ...
517 views

RootSum result manipulation/simplification

Consider the sum sum1 = Sum[ k/( k^7 - 2 k + 3), {k, Infinity}] ...
199 views

Plotting the solution of $\sin(x)\sin(y)$ + elliptic cylinder

I have a problem with one of my school project :( I need to add function: $\sin(x)\sin(y)$ to elliptic cylinder $\left(\frac x a\right)^2+ \left(\frac y b\right)^2 = 1$ After few hours, only this ...
497 views

Function with custom Options and modified Options for built-in Symbols

I couldn't find a more descriptive title, but I guess an example will explain my problem. I set up some customized Grid function including some additional ...
11k views

List of compilable functions

Is there somewhere a list on the functions that Compile can compile, or the cases in which a particular function can be compiled that I haven't found? I'd be glad ...
91 views

Argument attributes for pure functions [duplicate]

In his book, Leonid Shifrin says: One important limitation of the # - & notation for the pure functions is that it is ...
60 views

How to use part specification as a function [closed]

I need to define elements of a matrix as functions; For instance the element "Q_nk" of the matrix "Q", to be defined as: Part[Q, n_, k_] := ... So, I cannot do that and receive the error message "n_ ...
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domain of an input variable

Suppose I have a function called Exercise which is called in this way: Exercise[Gamma[x]+x*n,x] How can I indicate that n is a positive integer?
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Express anonymous with formal parameters [duplicate]

I'd like to express the function F = Function[{#2[[1]] + #1[[2]]/#1[[1]], #2[[2]] + 1/#1[[1]]}] using explicit formal parameters. I've tried ...
44 views

How to replace the argument of a function?

For the following expression, b'[x y/z]+z b''[x y/z] I want to replace the argument of b such that the above expression becomes ...
54 views

How to Write a code to automatically generate the planckian locus in (u,v) space [duplicate]

in the CIE XYZ color space the three coordinates defining an electromagnetic spectrum are given by XT=∫x( λ ) M( λ , T )dλ, YT=∫y( λ ) M( λ ,T )...