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

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1
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2answers
58 views

How to use the output we see of expression when this expression is inside Dynamic

Consider this example: Manipulate[status = Dynamic[If[a < b, Yes, No]], {a, 2}, {b, 5}] The output of this calculation is ...
2
votes
3answers
322 views

How can I get the function of a plotted trajectory? [closed]

I solved two ODEs, which are a function of t, numerically. The first ODE is the vertical equation of motion and the second one is the horizontal equation of that ...
1
vote
1answer
91 views

Attaching functions to movable locators

I'm trying to create a manipulate plot showing the electric field due to a collection of point charges. At the moment I've created such a plot which allows the x and y positions of each charge to be ...
10
votes
2answers
237 views

Why isn't Lookup treated like other symbols?

With Mathematica 10, I wanted to overload Lookup using TagSetDelayed, but it doesn't work. For instance, if I define two objects ...
7
votes
4answers
612 views

Solving $L=\frac{3}{2} \sqrt{4 \pi ^2 A^2+W^2}-\frac{\sqrt{5 W \sqrt{4 \pi ^2 A^2+W^2}+6 \pi ^2 A^2+3 W^2}}{\sqrt{2}}+\frac{3 W}{2}$ for $W$

When I solve the aforementioned equation for $W$ or $A$ on Mathematica I get a long and ugly equation in return, namely one of the solutions for $W$ is: (attempt to read at your own health) ...
8
votes
1answer
141 views

How to sort the functions in a Package?

Once a Package like abc` has been installed, we can use "?abc`*" to scan all the functions defined in this Package. Now I ...
1
vote
2answers
122 views

How to define logical expressions for platonic solids?

A more general question would be: How to find logical expressions for 3D-objects described by closed polygon sets? Finally a simple question is more prolific, therefore: How to define logical ...
2
votes
1answer
157 views

RegionPlot3D run forever when plotting 3D ParametricRegion

when working with 2D, RegionPlot works fine with ParametricRegion as can be seen in this example: ...
3
votes
5answers
359 views

How to add periodicity to condition?

Is it possible to set the following function f[a], where a can be any real number? $$ f(\alpha) = \begin{cases} 1 ...
0
votes
0answers
32 views

How to prevent function from substituting the part of the parameter name if it has a subscript? [duplicate]

I have the following problem, when defining and using a function, that's supposed to have an outside parameter xmin: A[x_] := Exp[-x/Subscript[x, min]] A[5] ...
2
votes
1answer
227 views

Finding average error of the data

Considering I have some data, and I want to fit the data to a linear fit and find the average error from the linear fit, how can I do that using Mathematica? I have ...
-2
votes
1answer
97 views

Compile Determinant [closed]

I would like to determine the determinant of a 4x4 matrix with the entries a[i,j] being functions of $i$ and $j$. I used Compile with code: ...
5
votes
1answer
196 views

How can I make a “self-referential” replacement operation self-contained?

Fairly often I find use for replacement rules that call themselves on the right-hand side of the rule, e.g.: ...
2
votes
0answers
123 views

How do I choose only one branch of ArcTan?

I have a problem concerning ArcTan drawing a graph using ListPlot. I import a table of data: ...
3
votes
0answers
53 views

Evaluating standard functions of general quaternions symbolically

Mathematica can easily compute exponentials and logarithms of concrete quaternions: ...
2
votes
1answer
105 views

How to explain the behavior of Rule inside these functions [duplicate]

I'm trying to define a function that takes an expression and spits out a pure function involving a replacement rule of that function's variable. An example would be a function ...
0
votes
0answers
29 views

Use FindRoot solution as number in function [duplicate]

I would like to save a number that I gain with FindRoot so that I can use it in another function. I tried: ...
1
vote
1answer
361 views

Remove curly brackets _completely_ to map a function to the elements of a list [duplicate]

Most list manipulations can be done with Flatten, Partition and Take. I didn't managed to ...
7
votes
1answer
242 views

Measuring time complexity of a method

I use ...
-1
votes
1answer
233 views

Find minimum function value in data and give coordinates of minimum

I create with Table an array containing the function value of some function and the n1and ...
2
votes
1answer
170 views

Finding the minimum of a function

I asked this question Mark Minimum Value in DensityPlot. Another question has come up, or better said, a task: Find the minimum of a function. I haven't been able to write the needed code for that, ...
2
votes
1answer
65 views

How to create a numerically “equal” function?

A simple example about what I need to do. For example, I have three functions: t1[x,t] t2[x,t] t3[x,t] and, ...
2
votes
0answers
158 views

Maximizing Large Multivariable Function over Region with Parameter Constraints

Brand new Mathematica user here. I have a complicated function to maximize, and thought I would try software like Mathematica instead of taking derivatives by hand. I found some Mathematica ...
0
votes
2answers
324 views

$RecursionLimit::reclim: Recursion problem

Please, find bellow my original question. Here is all my code: ...
8
votes
3answers
378 views

Does Mathematica have Month Range and Day range?

It is known that CharacterRange["a", "z"] gives list of characters from a to z. Does Mathematica have something similar for weekdays and months of the year? ...
0
votes
1answer
109 views

Problem with Maximize

As $\{p1,p2,p3,p4,p5\}$ represents a probability distribution and $l1,l2$ are the eigenvalues of a stochastic matrix, the function $f$, as defined below, has to be maximized over a certain region. ...
2
votes
3answers
89 views

Problem with InverseFunction of Sqrt

I want to build a table of InverseFunctions, f.e.: ...
4
votes
3answers
205 views

Is it possible to specify which range that slot takes from?

consider this example: ...
3
votes
1answer
449 views

Circular membrane vibration simulation

I'm new in Mathematica and I'm trying to simulate the vibration of a circular membrane for math project but I don't even know how to start. The wave equation describes the displacement of the ...
5
votes
4answers
401 views

How can I get the number of slots in Function?

Suppose that I define f = Function[#1 + #2]; And I want to define a new function, argsNum, so that it returns a number of ...
0
votes
1answer
32 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: ...
23
votes
2answers
495 views

Why is Query so much slower than Part?

Time for another of these(1),(2) as yet another new-in-10 function appears to have poor performance compared to older alternatives. This time: Query appears to be ...
2
votes
1answer
118 views

How to generate specific function using BSpline command/

I want to generate an approximation function that fits a curve to points. My goal is to obtain an actual formula. Is this possible with the BSpline function? Using the following code: ...
1
vote
1answer
174 views

Solving a trigonometric equation with one parameter

I have the following equation: 2 a^2 k^2 Sin[b k] - 6 a (k Cos[b k] - Sin[b k]/b) == 0 I set the value of b to 1, and I want ...
11
votes
5answers
319 views

How to prevent function from passing values to slot

For the following example: {#, #} & /@ {1, 2} I am trying to find a method to hold one of the slots (or both ) so that the function do not pass the values to ...
4
votes
1answer
346 views

Use of Strassen's algorithm

Strassen's algorithm is an algorithm for matrix multiplication that is asymptotically faster than the naive one. In practice, the matrices involved have to be quite large before Strassen's algorithm ...
2
votes
1answer
396 views

How to determine Fixed Point of a function? [closed]

A function is defined as f[x_]=Sqrt[1-x^2]. How can I determine the fixed point of f? I've tried this: ...
-2
votes
4answers
341 views

Compare elements in a list

Assume that there are three different points in x-y coordinate like: p1={4, -1}; p2={5, -2}; p3={1, 5}; In order to compare these points to each other in a ...
0
votes
0answers
34 views

How can Mathematica solve 7 equations and want to find 7 variables [duplicate]

I have 7 equations as below * e1 := (1 - a) p Subscript[A, 0] Subscript[s, K ] ! *SubsuperscriptBox[(s), (L), (-a)] = (1 - b) Subscript[B, 0] (1 - Subscript[s, K]) (1 - Subscript[s, ...
0
votes
2answers
142 views

prime-palindromic number selected from a list

I want to find all prime-palindromic numbers up to 5000. Prime-palindromic numbers are numbers that themselves and their reverse digits are both primes. For example, 31 is a prime-palindromic number ...
1
vote
2answers
123 views

An argument pattern that my function can treat as Times[constant, variable]

I want to define a function of two variables, func[f_, g_], such that when it sees a general constant multiplying one of the variables, say ...
7
votes
2answers
166 views

Probable Bug in HighlightMesh with 2D Convex Hulls created via ConvexHullMesh

One nice way to view the new and exciting Mesh objects introduced in Version 10 is by utilizing the function HighlightMesh, so ...
1
vote
0answers
208 views

Speeding Up Image Processing Functions

I am working with stacks of 1024x1024 timelapse microscopy images that I am performing a series of image processing functions on to help segment each image. These functions include ...
4
votes
1answer
100 views

How do I constrain variables to a user-defined domain in ArgMax?

I am trying to ArgMax a function over x, but x is only defined between ...
3
votes
2answers
418 views

Is there a function for nearest power of 2 in Mathematica like nextpow2 in MATLAB?

I am looking for something like nextpow2 in MATLAB like this: P = nextpow2(A) returns the exponents for the smallest powers of two that satisfy $2^P \geq\left|A\right|$.
3
votes
1answer
161 views

why Level does not sort output according to their levels

Consider this example: Level[a + f[x, y^n], {0, Infinity}] (*{a, x, y, n, y^n, f[x, y^n], a + f[x, y^n]}*) Why the output is sorted in this way. why not ...
2
votes
1answer
70 views

About Compile Function

I have a function that take p as a parameter, p is a 2X3X3 list, ( a 2X3X3 list can like { {{2,3},{1,2.},{1,1.}}, {{2,3.},{1,2},{1,1}}, {{2,3},{1,2},{1,1}} } ) the function just as: ...
1
vote
1answer
255 views

Computational complexity of symbolic determinant

I'm using the Det function in Mathematica to compute the determinant of an $n\times n$ matrix $A$ with entries of the form $a+bt$ with $a,b$ integers and $t$ a variable, and I would like to know what ...
0
votes
0answers
87 views

Problems with NMinimize

I have written some functions that take a matrix and find its minimum inner product with a specific set of vectors ...
3
votes
1answer
94 views

Quantile & TransformedDistribution

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