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

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4
votes
1answer
132 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
76 views

What are the differences between these functions when used for NMaximize?

In short, the question is how to construct the function you want to optimize? ...
0
votes
2answers
188 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 ...
8
votes
4answers
233 views

Is it possible to find generating functions of infinite sequences with Mathematica?

I'm trying to find the generating function of a sequence as $(0,1,0,1,0,1,\dots)$ but reading Mathematica's help on FindGeneratingFunction[] seems to tell me that ...
1
vote
2answers
160 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
62 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
votes
0answers
68 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 ...
1
vote
1answer
104 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: ...
1
vote
1answer
64 views

Aborting from a Dialog box

I'm trying to abort a While cycle, with a dialog box. I've tried the following: ...
18
votes
1answer
249 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
votes
1answer
155 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] ...
13
votes
0answers
215 views

More Ticks::ticks errors in AbsoluteOptions in v10

Bug introduced in 7.0 or earlier and persisting through 10.2 or later While the specific bug affecting Plot described in AbsoluteOptions prints error messages in ...
0
votes
2answers
81 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 ...
0
votes
3answers
119 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)
0
votes
0answers
83 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
votes
0answers
43 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
votes
4answers
261 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
votes
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
vote
3answers
77 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
127 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
77 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 ...
17
votes
2answers
276 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
votes
1answer
61 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
78 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
votes
3answers
114 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
2answers
189 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
2answers
743 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
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 ...
1
vote
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
votes
4answers
725 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
100 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 ...
1
vote
0answers
54 views

Improving RationalInterpolation Result

The following code produces a {4,4} rational interpolation approximation accurate to 10^-6 or better over the range ...
1
vote
1answer
99 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
76 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
votes
1answer
274 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
votes
1answer
51 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
votes
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
vote
2answers
2k 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
140 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
votes
3answers
221 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
1answer
91 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
votes
2answers
216 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
vote
0answers
162 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
votes
3answers
164 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
50 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
vote
0answers
40 views

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

I start with the following input: f[n_] = Sum[(1+x)^j, {j,1,n}]; g[n_] := Sum[(1+x)^j, {j,1,n}] When I try to evaluate the code above I get: ...
2
votes
1answer
122 views

Show how Eliminate arrives at reduction

Does anyone know how to get Mathematica to show how it arrives at the following result? ...
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
78 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 ...