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

learn more… | top users | synonyms

2
votes
2answers
159 views

Generating a permutation of elements in chunks

Is there a way for me to generate a list of permutations in "chunks" such that I needn't store everything on RAM all at once? Consider that (WARNING: DO NOT RUN! --- Will generate a list with 13! = ...
2
votes
1answer
57 views

Double application of NIntegrate produces unexpected error messages [duplicate]

In the course of trying to answer 69601, I encountered unexpected error messages. In highly simplified form, NIntegrate[NIntegrate[z y, {y, 0, 10}], {z, 0, 10}] ...
13
votes
11answers
1k views

Divide all but the maximal element in a list by 10?

I have a list of numerical data, and I want to write a program that will keep the maximum as it is, but reduce the rest by certain factor (such as 10). For example: ...
1
vote
1answer
1k views

Computing the fundamental matrix and its monodromy matrix

Assume $\dot x(t)=v(x,t)$ is a $T$-periodic, with respect to $t$ dynamical system. That is: $x\in\mathbb R^n,\quad t\in\mathbb R,\qquad v(x,t+T)=v(x,t)$. Let $x_0$ be a smooth periodic solution in ...
4
votes
1answer
171 views

Coefficients of a polynomial in powers of 10

Can I express a polynomial function in Mathematica in power (ScientificForm) ? I was trying: ...
1
vote
0answers
78 views
0
votes
2answers
412 views

Replace variables and redefine a function

I would like to redefine a function f(x)=1+2x^2 to a new function g(y)=1+2y by using the replacement ...
1
vote
2answers
171 views

Josephus problem

See the Josephus Problem. My code takes in two numbers; one is the number of participants, and the other is supposed to be the number of players skipped between executions. ...
1
vote
2answers
67 views

Incomplete Integration in Area

Area[2 Sqrt[(1 - p^2)^2 - r^2], {p, 0, 1}, {r, 0, 1 - p^2}] is able to perform only the integral over r, leaving the integral ...
1
vote
1answer
79 views

Aborting from a Dialog box

I'm trying to abort a While cycle, with a dialog box. I've tried the following: ...
11
votes
2answers
1k views

Growth of functions

Does somebody know if Mathematica can be used to calculate the growth of functions, that is in Big O, Theta, and Omega and find proper $n_{0}$ and $c_{1}$, $c_{2}$ respectively?
3
votes
1answer
164 views

Function that returns the second argument of Reap

I'm trying to create a function that returns only the second argument of Reap. Here's my naive guess of how it would go : Reap2[x_]:= Flatten[Reap[x][[2]],1] ...
1
vote
3answers
221 views

Can I find constants in a function?

Let's say, I have a function with a constant, e.g. $y(x)=x+c$, and a condition $y(0) = 5$. I want to type in something like Solve[{y[x]=x+c, y[0] =5}, {c}] and get ...
16
votes
2answers
267 views

A bug in Commonest in version 10

Bug introduced in 10.0.0 and fixed in 10.0.2 m_goldberg demonstrated that in Mathematica 10 Commonest does not behave as the documentation indicates that it ...
0
votes
3answers
169 views

choose any number e that is relatively prime to n

I try to write a command that means choose any number e that is relatively prime to n, like e^n [Congruent] 1 (mod n), but it didn't give me a value of e. e^n [Congruent] 1 (mod n)
8
votes
2answers
276 views

Difference between Evaluation>>Quit Kernel and Quit[]

What is the difference between Evaluation >> QuitKernel and Quit[]? Both seem to quit the kernel (and clearing all ...
0
votes
0answers
46 views

Regarding Cycles and Lists of Functions

So, I'm trying to determine the Normal Matrix of a Least Squares Aproximation; I have a basis constituted by 8 functions f1,f2...f8; I have 9 points which constitute Datax = {x1,x2...x9} Now, I ...
0
votes
2answers
68 views

Binding trigonometric terms

I have many terms like A = Cos[Pi/18 + 2 x] + Cos[Pi/18 - 2 x] and I want to convert A to ...
1
vote
3answers
97 views

Defining a function using a preceding expression

How can I automatically define a function inside my Mathematica code using a result (expression) that preceded the point of definition. For example: ...
2
votes
1answer
175 views

Quantize a real-valued function?

I'm wondering if there's a built-in way in Mathematica to take a function whose output values are continuous, and quantize it to produce a step function. For example, I have the function ...
11
votes
2answers
279 views

How do I override options with my own defaults?

I'm calling a function f from within a function g and would like to pass any valid options for ...
0
votes
1answer
69 views

Defining a function with algebraic parameters

I am trying to define and use a function to represent the eigenstates of a Quantum Harmonic Oscillator, which have the general form: $$\psi_{n}(x) = \frac{1}{\sqrt{2^{n} n!}}\left(\frac{m \omega}{2 ...
2
votes
2answers
103 views

Define function over expression

Suppose I have the following expression system = x + y + z And I would like to define a function that contains this function, without explicitly typing the right ...
8
votes
1answer
149 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 ...
0
votes
3answers
167 views

Defining a function which displays odd numbers? [closed]

Define a function that takes as input an integer n and returns as output the product of the first n odd numbers., i.e., 1 · 3 · 5 · · · 2n − 1. Evaluate your function at 1, 2, 3 and make sure you get ...
6
votes
3answers
251 views

How to define a nested function like this?

For example, I want to calculate the limit of $\frac{1}{1+\frac{2}{1+\frac{3}{1+\ldots}}}$. So I want to define: $f(1)=1$ $f(2)=\frac{1}{1+2}$ $f(3)=\frac{1}{1+\frac{2}{1+3}}$ Then I calculate ...
0
votes
2answers
807 views

How to find volume of an egg [closed]

I am a first time user of mathematica. I've been trying to figure out how to find the volume of a) f(x)=(ax^3 + bx^2 + cx + d)sqrt(1-x^2). I have been scouring the internet for a solution on how to ...
3
votes
0answers
68 views

Lists for built-in functions that can work without brackets

I just noticed that Exit and Quit can work without brackets i.e. a single Exit or ...
1
vote
1answer
100 views

FinancialData Input

What does the function FinancialData require as input for natural gas: http://finance.yahoo.com/q?s=NGG15.NYM Is it easier to export the natural gas data to ...
2
votes
1answer
283 views

How to make a function from body with variable number of arguments?

Suppose I have an UNKNOWN function, which generates formulas with given number of x[i]. ...
1
vote
1answer
212 views

Composition of Multivariable function

I am trying to compose functions of xleft, maybe like xleft[xleft[f]] or even higher order. And here is my function: ...
0
votes
1answer
77 views

Diffentiating a function f with respect to x [duplicate]

I have a tabe y={10,20,30,40...} and x={62,63,64,65...} y is a function f and this function needs to be interpolated. How do I defferentiate the function f with respect to x?
0
votes
1answer
68 views

Taking function output as shown, and processing it regardless of its history

I am making some symbolical calculations for my quantum chemistry class. I am supposed to build a wave function composed of multiple other functions, each of which is also composite of some lower ...
5
votes
2answers
7k views

How to tell Mathematica that certain variables are real/imaginary, integer-valued, etc

I'm trying to expedite some quantum mechanical calculations by running them through Mathematica. Expectation values and stuff like that. When I say, for example, ...
0
votes
1answer
58 views

What is the simplest way to obtain function obect of a given function?

Suppose I have a function p of some arguments: p[x_,y_]:= (* something *) Now I with to pass this function as an object to ...
1
vote
1answer
163 views

Why does LyapunovSolve solve non-standard form?

LyapunovSolve[A,Q] solves the equation $A P + P A^T = Q$ for $P$ whereas the standard form (wikipedia,lecture notes, p.25, linear control systems) of the Lyapunov ...
12
votes
1answer
369 views

Better Autocompelete for the Front-End

I wonder if it is possible to improve the front-end's autocomplete capability. Compared with some other more sophisticated editors/IDEs, such as eclipse, Mathematica's front-end does not provide a ...
1
vote
0answers
237 views

Crosscorrelation for nonperiodic signals

I want to detect patterns (of an absorption spectrum which is nonperiodic) with Mathematica automaticly. I have found CorrelationFuncion but as far as I understand, ...
1
vote
1answer
307 views

How can I call the R-programming packages in my Mathematica?

I am trying to call the R-programming package called highfrequency in my Mathematica so that I can use its function rCov. I ...
2
votes
2answers
343 views

cycloid parametric [closed]

How do I enter 3 parametric equations for cycloids corresponding to circles with radii 1, 2, and 4. I have tried ...
5
votes
3answers
167 views

Missing control for depth of Inner

Working on a mechanics problem, I stumbled on something peculiar: Since Inner is a generalisation of Dot, it changes its ...
1
vote
2answers
53 views

How to add a part of a list to a function?

I want to be able to add a specific portion of a list to a part of a function but this fucntion intakes 6 variables where as the list is of example: ...
2
votes
1answer
126 views

Show how Eliminate arrives at reduction

Does anyone know how to get Mathematica to show how it arrives at the following result? ...
-1
votes
1answer
420 views

Putting two functions in one manipulate plot

I have a problem that is somewhat related to this http://stackoverflow.com/questions/7727668/putting-two-plots-in-a-manipulate-whilst-keeping-the-plots-visible but I would like to plot two functions ...
1
vote
1answer
80 views

Help creating a simple function

Can someone help me to create a function. The truth I'm new in Mathematica and I don't understand well the way functions work in I. I need a function that animate some rectangles according to a curve ...
3
votes
1answer
83 views

Integrate[] does not work when the function has an antiderivative function

This function (1 + (1 + 1/(2*Sqrt[x]))/(2*Sqrt[Sqrt[x] + x]))/(2*Sqrt[x + Sqrt[Sqrt[x] + x]]) has the antiderivative function, since ...
1
vote
1answer
227 views

using a Mathematica function to define a new function

I'd like to define a function of three variables which produces a new, named function of a single variable, where this final variable is not a member of the first three. So I'd like something where I ...
1
vote
1answer
177 views

using Module in NDSolve

I am trying to solve a set of two wave equations where solution of first equation defines initial conditions for the second one. And I would like to use Module to define those equations as a function ...
1
vote
1answer
135 views

Apply functions to functions yields slow execution speed

I'm trying to write a function that parametrizes a curve c(t) by its arc length. Technicly I'm finished but if I plot the result for an example curve like ...