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

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0
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0answers
50 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
67 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
74 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
258 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
44 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
52 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
811 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
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1answer
122 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
208 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
60 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
172 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
122 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
161 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 ...
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2answers
47 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
115 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
78 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
votes
1answer
187 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
198 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
120 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
89 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 ...
15
votes
7answers
584 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 ...
1
vote
1answer
136 views

Manipulate - Evaluating Value of Function

I would like to visualize the properties of a threshold, which is a value of a function. Unfortunately, the value is expressed as scientific value (an approximation with 3-5 decimals would be fine) ...
1
vote
0answers
28 views

Apparent issue with derivative of FractionalPart

This issue came to my attention from Math.SE: http://math.stackexchange.com/questions/1015325/is-the-derivative-of-x-on-0-1-always-equal-to-1/1015342#1015342 To summarize, it appears that ...
1
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1answer
119 views

In there a way to derive the inverse value of CDF format MultinormalDistribution?

Is there a way to produce the inverse value of multinormal distribution function in CDF format with 0.05 significance level? I found the function called ...
0
votes
0answers
106 views

simulate a 32-bit signed integer overflow in a recurrence function

Considering the following recurring equation: which is this factorial function: I want to find the value of x where f(x) = 0. Actually, the solution is impossible with Mathematica, and it's ...
0
votes
1answer
78 views

Error: in the part assignment is not a symbol [duplicate]

I am trying to set part of a Doubly-indexed list aInitialPopulation to cNumHeg. Specifically I am trying to set the 3rd part of the list aInitialPopulatiom[[cNodeNumber]] to cNumHeg. My (attempted) ...
6
votes
5answers
173 views

What is the shortest way to switch between heads of nested functions

consider this example: f[g[x]] what is the shortest way to switch between heads of nested functions to produce. g[f[x]]
2
votes
1answer
91 views

Using Integrate to define a function

I'd like to define a function by way of the output of a definite integral with symbolic bounds. For instance, F[m_,k_] := Integrate[x,{x,m,k}] would define ...
1
vote
0answers
44 views

RowReduce doesn't work for this matrix?

I have this matrix A={{0,1,1,w},{1,0,1,x},{-1,0,1,y},{0,1,1,z}} where w, x, y, z are arbitrary constants. This matrix should be row reduced to the form ...
12
votes
2answers
2k views

Which Mathematica function has the longest name (by character length?)

I came across DamerauLevenshteinDistance[u,v] in the documentation center so that got me thinking: Which documented Mathematica function has the longest name? ...
0
votes
0answers
42 views

Should this be equal to Gamma function or not?

I define the following function: Nat2[s_] := InverseFourierTransform[FourierTransform[1/t, t, w] (-I w)^(s - 1), w, x]/Cos[Pi (s - 1)] /. x -> 1 I expected ...
10
votes
1answer
263 views

Why does the documentation call functions “pure”?

Clearly, functions in mathematica are not pure functions according to the definition on Wikipedia (no side effects - basically implementabe with table lookups): ...
1
vote
1answer
210 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 ...
1
vote
1answer
110 views

handling division by zeros and line equations

today I was writing a code which takes some line equation and a circle equation,finds intersection points that are on $II$ and $III$ quadrants,draw a tangent line to circle from that point and then ...
0
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0answers
129 views

Empty Graph for Absolute Function

I wanted to plot the following equation: Plot[((x/7)^2 Sqrt[(Abs[Abs[x] - 3]/(Abs[x] - 3))] + (y/ 3)^2 Sqrt[(Abs[y + 3 Sqrt[33]/7])/(y + 3 Sqrt[33]/7)] - 1) (Abs[x/2] - ((3 ...
1
vote
1answer
47 views

Multiway Systems Rules List Management

I'm working with a multiway system and I have a number of different mutation rule lists. I need an efficient way of managing which rule lists I apply. Here is the basic multiway system code that I'm ...
1
vote
1answer
86 views

Plotting a function in {X(Y),Y} space

The code below generates some data and defines a function f[x,cb]:=NMaximize[expr,x] that upon being evaluated returns: {function value at max $x$,the function maximizing $x$}. ...
7
votes
2answers
192 views

How to redefine the type of multiplication in Det

I would like to redefine the type of multiplication that is used in Det (calculates the determinant). Instead of the standard multiplication I would like to use a custom function Fun[a,b] (which takes ...
14
votes
1answer
252 views

Why do big-O terms disappear in definite integrals since Mathematica 9?

In Mathematica 8, when I computed the following input: Integrate[Series[Cos[x], {x, 0, 2}], {x, 0, a}] Mathematica returned an expression that had a O[a^4] in ...
3
votes
1answer
91 views

FinancialDerivative function call without parameter fails in Mathematica 10

fixed in 10.0.2 When I type FinancialDerivative[] in Mathematica 10. There is error listed as follows. Anybody know how to solve it? Thanks.
1
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1answer
68 views

User defined functions and decimal places displayed

I have a couple of complicated user-defined functions, one which calls the other, and I wish to control the number of decimal places displayed when I call the "mother" function. I have tried the ...
1
vote
1answer
65 views

In which version was this Extract syntax introduced?

In Mathematica 10.0.1 this works: Extract[{a, b, c, d, e}, {{{1, 3}}, {{5, 4}}, {{2}}}] {{a, c}, {e, d}, {b}} In ...
2
votes
0answers
27 views

Automatically discover the class of an arbitrary matrix

In Wolfram|Alpha it is possible to discover some specific classes to which a matrix belongs. For instance, typing this in Wolfram|Alpha ...
0
votes
0answers
60 views

Birch clustering in Mathematica

I want to implement birch clustering in Mathematica. MAthematica only has 4 methods of clustering, is there any implementation for Birch clustering? Birch clustering is much faster than K means ...
3
votes
0answers
138 views

Distance Time Warp (DTW) function implementation in mathematica

The DTW (Distance time warp) is given here http://en.wikipedia.org/wiki/Dynamic_time_warping There is an implementation of DTW in R as well as MATLAB. However i am unable to find something for DTW in ...
0
votes
1answer
43 views

How to rearrange CharacteristicPolynomial[ ] terms?

I have a symbolic matrix A, which I need to find the characteristic polynomial, then order the polynomial in greatest-to-least form. (Ultimately to find the matrix inversion via Cayley-Hamilton ...
2
votes
2answers
83 views

Returning the 3-dimensional vector from a skew symmetric matrix

I'm trying to write a function that takes in a skew symmetric matrix and returns the corresponding vector. When I write the following code, it works when I leave it as variables, but it does not work ...
0
votes
1answer
71 views

How to evaluate a “pure function”? [closed]

I need to evaluate the result of DSolve, e.g. {{y -> Function[{x}, x^2 - x^3]}} at some specific point. I tried y[1] and y /. x -> 1. Hope someone knows how to do it