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

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3
votes
2answers
135 views

UI characteristic function [closed]

I have three given points: $\qquad $A$\qquad $(0; 5.9) $\qquad $B$\qquad $(18; 5.56) $\qquad $C$\qquad $(22.32; 0) I don't know how I can create a function like the one in the image below with ...
0
votes
1answer
52 views

How to create a function that can be evaluated for specific values [closed]

I have been trying to create a function to compute a field and perform operations with it, however when I try to define it I have used: ...
7
votes
1answer
115 views

Generalizing LongestCommonSequence to 3 or more arguments?

The function LongestCommonSequence finds a longest common subsequence between 2 lists. Apparently, this built-in function does not accept more than 2 arguments. How ...
0
votes
1answer
42 views

Selecting terms on only one variable from a multiple-variable expression

Say I have a polynomial like $x y^2+15x^2 y+x+3y+10$ and I want to obtain, say, only the coefficient in $x$ alone, namely a 1. Using ...
5
votes
1answer
1k views

How to take the derivative w.r.t. an arbitrary function?

EDIT: The answer posted by @Jens works for built-in functions only. However I'm starting to wonder if this is related to my Mathematica install somehow. I have version 7. Here is an example in the ...
1
vote
1answer
50 views
0
votes
1answer
36 views

Parameterize Subset of Complicated Zero Set

I recently asked this question: Evaluating Functions on Zero Sets (of other functions), and got fantastic assistance, but realized that there seems to be an extra issue when you're trying to ...
3
votes
2answers
133 views

Replacing multiplication of matrix elements by application of these elements as functions

I want to realize the following idea in Mathematica. I've got a matrix {{a,b},{c,d}} which is multiplied to a vector {h,k} ...
3
votes
2answers
109 views

Evaluating Functions on Zero Sets (of other functions)

I have a highly non-trivial function, call it $f(x,y)$, in which I want to look at its zero set in the $(x,y)$ plane, and plot/evaluate a different function $g$ precisely along this zero set. I have ...
0
votes
0answers
34 views

ApartSquareFree function

I have a doubt concerning the ApartSquareFree function in Mathematica. Roughly speaking, it is supposed to compute the partial fraction decomposition of a rational function $h/g$ with the denominators ...
8
votes
1answer
111 views

What is ExpectationE and what does it do?

I just found the symbol ExpectationE with autocomplete. Rendered the symbol is Searching the documentation and the internet leads to nothing. Does somebody ...
15
votes
1answer
135 views

Is it better to completely forget about the existence of PowersRepresentations?

I noticed that in several cases the performance of PowersRepresentations is hugely worse than that of IntegerPartitions. (Mma 10....
1
vote
0answers
35 views
2
votes
1answer
71 views

ListPlot of auto-correlation function pushes data 1 lag

I'm trying to plot a graph of a sample autocorrelation function at different lags. The code I'm using is ...
1
vote
0answers
39 views

Getting a list of function definition parameter values [closed]

If I define a function over certain values: f[0] = 1 f[1] = 2 f[2] = 3 How do I get the list of parameter values that it's been defined on? ...
-1
votes
1answer
66 views

Plotting a function of another function

Edit: So I have several functions which come from other functions. For example: ...
-1
votes
1answer
86 views

How can i 2d-plot Cobb-Douglas function?

can I plot Cobb-Douglas function in 2D without using ContourPlot? I have this function: u[x1_, x2_] := Log[x1] + 2*Log[x2]; and now I plot it using: ...
1
vote
4answers
142 views
1
vote
2answers
68 views

Selecting points in list that are inside a contour [duplicate]

I have a list of points which form a closed (connected) contour or path in two dimensions. I would like to get all points from a second list which satisfy the requirement that they are inside the ...
4
votes
2answers
4k views

Plot Even Piecewise function

Is it possible in Mathematica to plot an even piecewise function like: $ f(x) = \begin{cases} 3t , 0 \le t \le \frac{\pi}{2} \\ 3t + 6 , \frac{\pi}{2} \le t \le \pi \end{cases}$ which has ...
3
votes
1answer
77 views

Pareto optimal fronts using internal function?

Reading this question: How do I estimate the Pareto front in my multiobjective optimization problem? I found @Daniel Lichtbau's interesting answer. Yet I don't know how such an "internal function" ...
5
votes
0answers
139 views

Is there an internal logic behind short form symbols, such as @ (Prefix), @@ (Apply), /@ (Map), /. (ReplaceAll) [closed]

To me, function names (such as Apply and Map) seem more intuitive than their symbols (e.g. @@...
11
votes
1answer
128 views

Definition of Mod and Quotient with complex arguments

How are Mod and Quotient defined for three real/complex arguments? I wasn't able to find the definition. My main surprise so ...
26
votes
1answer
530 views

In 10.1.0 BenchmarkPlot doesn't work?

Bug introduced in 10.1 This bug was resolved in 10.2.0, but another bug was introduced in 10.3.0 persisting through 10.3.1 and finally resolved in 10.4 In Mathematica 10.1.0 and 10.3.0 ...
1
vote
0answers
54 views

How to avoid tranfer the array as a parameter [closed]

I have following array: data = {x^2, 2*x^2, x^3}; And I must send it to the following function: ...
1
vote
1answer
111 views

Evaluate pure function through round brackets

In have some matrices of pure functions or numbers which I multiply by other matrices or vectors. I would like the functions to be evaluated in the result, but all that I get is something like this: <...
0
votes
0answers
29 views

PolynomialExtendedGCD in 2 variables

Consider a field $R$ and the ring $A=R[y]$. Consider two polynomials $g,h\in A[x]$. I want to obtain $d=\gcd(g,h)\in A[x]$ and two polynomials $s,t\in A[x]$ satisfying the Bézout relation: $sg+th=d$. ...
2
votes
2answers
58 views

Substituting within a function definition that includes Simplify

I would like to define a function like myfunc[f_] := Simplify[(f/g)] where g will be substituted/replaced with the current value of g at the time of definition. ...
3
votes
1answer
68 views

Checking if input is a function

I would like to write a program to find the leading coefficient of a given polynomial. (Sounds easy, right?) I'd like to be able to handle the format x^2-x+7 (with ...
3
votes
3answers
182 views

Return a sentence with numerical values

I have the following function: example[a_, b_] := Module[{c}, c = a + b; Return["The solution is c"] ] I would like to know how to return that ...
10
votes
1answer
176 views
0
votes
1answer
58 views

Transform a variable's exponent from an exact rational to an inexact decimal

here is a little problem I could not find a solution for. I have a variable with an exponent represented as a fraction, for example, var = a^(39/106) Now I ...
6
votes
2answers
323 views

What does empty {} mean in Module? [duplicate]

I have a question. I would like to know what an empty list ({}) means when used in Module[] as the code below shows? Why has a ...
16
votes
1answer
370 views

GeoGraphics: problem with GeoPosition in shifted projections

Bug introduced in 10.0.0 and persisting through 10.4.1 A remark about the answer: My work around is only nice for simple cases with points. More general should include proper polygons splitting on ...
1
vote
2answers
107 views

n fold convolution of a function via a recursion function

I wanted to write a recursion function to calculate the n-th convolution of a function f[x_]. I wrote the function ...
0
votes
1answer
63 views

Partial derivative of function of two variables

This question is not enlightening nor is it difficult. But some part of my notation or how I have defined my functions is messing up the D[f,x] function. ...
10
votes
0answers
118 views

Possible Bug in LinearSolveFunction with Sparse Vectors

Bug introduced in 5.0 and persists through 10.4.1 LinearSolveFunction is new in 5.0 Consider the following set of equations and corresponding variables: ...
16
votes
1answer
368 views

What has changed in the Template system in 10.3?

Bug introduced in 10.3 and persisting through 10.4.1 There are couple of issues that are breaking my code after upgrading to 10.3. I wasn't able to narrow all of them down but this is what I've ...
3
votes
1answer
70 views

Calling results of applying f to expr inside NestList

Being new to Mathematica, I try to follow the suggestions of using NestList, Map, Table ...
3
votes
2answers
47 views

Better alternative to Hold/ReleaseHold for postfix application of Monitor

Trying to Monitor a process using the postfix notation, as in Table[Pause[n/10], {n, 5}] // Monitor[#, n] & fails: the ...
6
votes
1answer
72 views

Custom operator form for system functions?

There are some functions for which an operator form would make sense but isn't implemented. For example, I'd like to make this work: RandomSample[3] @ Range[10] ...
5
votes
4answers
247 views

Results in terms of a function

Let's assume I have a function $f(x)=\exp(10x^2)$, i.e. f[x_]:= Exp[10*x^2]. When I differentiate $f$ by evaluating the expression ...
-2
votes
1answer
77 views

Plotting 3-dimensional graphs [duplicate]

I just started Calculus 3 and I thought it would be useful to see images of functions to get used to the transition of visualizing in 3-dimensions. I was wondering how one would go about plotting a ...
5
votes
2answers
174 views

Get envelope of a set of functions?

I'm new with mathematica and I'm trying to solve a problem. I have a set of functions in the same variable. Let's say the domain is [0,2]. I would like to get an ordered list of the functions ...
3
votes
1answer
55 views

Undocumented “Output” alignment argument to “Column?”

In this SE question, Inheriting Stylesheets when using CreateDocument, I noticed the literal string argument "Output" to Column. ...
0
votes
0answers
98 views

Impose a boundary condition to a function

Background I am trying to impose a boundary condition on a function of two variables $u(x_1,x_2)$. The boundary condition is: $u(x_1,0)=A\cos(\omega x_1)$. The same function in mathematica $u(x_1,0)$...
0
votes
0answers
49 views

How to calculate a continuous function once and access values later?

I have a function that involves a numerical calculation: h[v_]:=NIntegrate[f[x]*Log[p[x, v]], {x, -Infinity, Infinity}] I need to visualize how well a bunch of ...
3
votes
2answers
71 views

Calculate Cumulative Mean and Standard Deviation of a list without FOR loops [duplicate]

I have a simple list mylist={x_1,x_2,...,x_N};. Now I want to map a function over this list, e.g. the Mean and StandardDeviation functions, so that it will give me ...
2
votes
1answer
149 views

Creating a function takes a list and dynamically modifies that list [duplicate]

I'm trying to create a function that uses a dynamic locatorpane to populate a list with the coordinates of user defined locators (added by alt+clicking). This code works fine: ...