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

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2answers
141 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
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2answers
59 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 ...
0
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0answers
61 views

Plot function failure, and understanding how mathematica selects recursion points for correction

I think it is best to start out by directing everyone to this link. The discussion concerns why the Plot function fails to accurately generate a simple sine wave for given parameters. The answer given ...
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1answer
98 views

How to fill a Marshal buffer with whitespace using NETLink

Further to Todd Gayley's answer on string handling in a DLL function, I have the following code: ...
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1answer
60 views

Aborting from a Dialog box

I'm trying to abort a While cycle, with a dialog box. I've tried the following: ...
14
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0answers
161 views

Default behaviour of Hash[expr] and hashing in different versions of Mathematica

In different versions of Mathematica, Wolfram silently changed the behaviour of Hash when the algorithm is not specified explicitly ...
3
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1answer
154 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] ...
10
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0answers
173 views

More Ticks::ticks errors in AbsoluteOptions in v10

Bug introduced in 7.0 or earlier and persisting through 10.1 or later While the specific bug affecting Plot described in AbsoluteOptions prints error messages in ...
0
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2answers
78 views

Choosing pairs from a list that satisfy a certain equality [closed]

If I have many numbers in here {{A,B},{C,D},{E,F}.....} And I want choose the B,D,F,....(the second number) to run a function y=f(x), where x=B,D,F.... Then I need to check if y=f(B) is equal to A or ...
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3answers
112 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)
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0answers
82 views

How to conveniently stop a programme without aborting the computation

I have a programme that will have to run for a few days. However, I would like the user to have the option of stopping the computation of the code, without aborting it, when he desires, without ...
0
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0answers
42 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 ...
6
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4answers
226 views

What is shorthand way of Reap list that may be empty because of zero Sow

Sometimes because of conditionals, you cannot guarantee that Sow will be called at least once. Reap[Sow[1]][[2,1]] results in ...
0
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2answers
61 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
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3answers
71 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
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1answer
118 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 ...
2
votes
1answer
74 views

How to package a function for export?

I often post code for functions on Stack-Exchange, and then later find that they are unexecutable - that people can't use them because I mistakenly omitted some private functions or values that are ...
16
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2answers
243 views

Where is the old option TraceInternal->True?

Already at least in version 2 (I think), the function Solve calls the function Roots. At that time, I had a rather dirty trick, that still works, to verify this: ...
0
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1answer
59 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
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2answers
77 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 ...
0
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3answers
105 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
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2answers
171 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
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2answers
732 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
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0answers
61 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 ...
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1answer
89 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 ...
11
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4answers
628 views

Generating Random Real numbers with certain numbers not included

I'm writing a program that i need 1000 real number between -3 and 6. the code that I used for generating and saving them was l = RandomReal[{-3, 6}, 1000] But I ...
3
votes
1answer
97 views

RegionPlot fails when given function with internally redefined variables

I've just upgraded to v10, and have noticed that some of my trusty old notebooks which used RegionPlot now fail to run. I've boiled down the problem I'm having to ...
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0answers
51 views

Improving RationalInterpolation Result

The following code produces a {4,4} rational interpolation approximation accurate to 10^-6 or better over the range ...
1
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1answer
84 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
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1answer
75 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?
2
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1answer
265 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]. ...
0
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1answer
47 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 ...
0
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1answer
53 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
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2answers
1k 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, ...
1
vote
1answer
138 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 ...
6
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3answers
216 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
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1answer
73 views

Mathematica Lattice Reduce Command

I'm going through a very old copy of "Mathematica: A System for Doing Mathematics by Computer" for self practice. I'm on chapter 3, and ran into the LatticeReduce ...
2
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2answers
200 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 ...
1
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0answers
138 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, ...
5
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3answers
162 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
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2answers
49 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: ...
1
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0answers
30 views

Why the same function defined by Set and SetDelayed look different? [duplicate]

I am novice to Mathematica and maybe my question looks kind of silly, but nevertheless here is it. I input two functions: ...
2
votes
1answer
119 views

Show how Eliminate arrives at reduction

Does anyone know how to get Mathematica to show how it arrives at the following result? ...
1
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1answer
79 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
77 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
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1answer
230 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 ...
11
votes
2answers
207 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 ...
1
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1answer
129 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
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1answer
98 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 ...
16
votes
7answers
604 views

Enumerating tuples from a larger space such that all pairs of values are present at least once

I am trying to write a function that will accept a list of N lists and returns a list of N-tuples that represent all pairs of values from the original N lists at least once. To illustrate with an ...