# Tagged Questions

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

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### How to call a function with an arbitrary list as its arguments inside a functional? [duplicate]

I have the following functional defined (i.e. a function of another function) where variableList contains the variable (arguments if you wish) of the ...
474 views

### Permanently rounding numbers/values to a given number of significant figures

I am searching for a simple way of rounding and setting an input to a desired number of significant figures. There are a vast number of posts that discuss similar problems, but none address this issue....
37 views

### Replace argument of delayed function before it evaluates [duplicate]

How should I use replace so that f[x_] := x^2 Replace[f[3], 3 -> 1] OUT = 9 evaluates to 1, instead of 9? This way, the replacement of the argument is done ...
2k views

### Scan vs. Map vs. Apply

I cannot understand the difference between Apply, Scan, and Map. I have tried to play with ...
122 views

### What is wrong with my code so it neither produces a correct plot nor an error message?

I am trying to define some initial functions and then using them to define my secondary functions and then plot the secondary functions. I am supposed to get two curves with a finite width ...
127 views

### Plot two curves and confidence bands representing the uncertainties in their parameters

Here is the plot I want to make using Mathematica 8.0 : ...
38 views

### finding list by expresion [closed]

Well Im new to mathematica. I have list of x which contain {1,23,45,6,43}. And I get expression from g = Fit[t, {1, v, v^2}, v] how can apply list x to g to ...
242 views

### Symbolically Expanding One-Variable $q$-hypergeometric Series

In general, how do I get Mathematica to symbolically expand various infinite series to an arbitrary degree of accuracy? I deal with $q$-hypergeometric series quite frequently, and specifically want ...
208 views

### How to get exact coordinate of a point from a plot?

I am using BodePlot[] to plot the magnitude and phase of a function as below. BodePlot[1000/((1 + s/10^3)*(1 + s/10^6))] ...
70 views

### Extended AutoCorrelation Function

Is there a function in Mathematica capable of computing the sample Extended AutoCorrelation Function (EACF)? I know that there's a package in R that does this. I was trying to avoid to having to ...
3k views

### Flatten command: matrix as second argument

One thing I could never wrap my head around is how Flatten works when provided with a matrix as the second argument, and the Mathematica help isn't particularly ...
66 views

### How to plot a function whose constant parameters have associated uncertainties in Mathematica 8.0?

Let's assume I want to plot the function $f(x)=a + bx+ cx^{2}$, where experimentally known values of parameters $a, b$ and, $c$ are as follows: $a=1.01 \pm 0.18$ $b=0.92 \pm 0.11$ $c=2.2 \pm 0.2$ ...
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### Can I create a mouseover summary or documentation for a new function?

In Mathematica, when you hover any a built-in function, a small window with 2 symbols appears (as in the third paragraph of this reference page, see picture): clicking on the former one gives you a ...
85 views

### Trying to create an interactive plot (newbie here)

I'm new at Mathematica so please bear with me. I am trying to create an interactive plot that will end up looking like this: I want to input values for certain variables and then plot a curve. This ...
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### FourierSeries command , for arbitrary period T?

ExptoTrig[FourierSeries[Piecewise[{{-Pi,-2Pi<x<=0},{Pi,0<x<=2Pi}}],x,3]] You can see, the function goes from $(-2\pi,2\pi]$ But Wolfram Alpha gives a ...
1k views

### Why is there no PositionFunction in Mathematica?

Too often I have seen the programs of inexperienced users greatly slowed by using Position in an iterative fashion, when far faster would have been to compute a ...
259 views

### Operations on transfer function model

Suppose I have a transfer function defined via TransferFunctionModel, e.g. tf == TransferFunctionModel[{{1/s}}, s]. How can I ...
60 views

### Defining functions as derivatives

I'm working on a model that requires a sum over a function that uses various coefficients. In order to make the sum easier to perform, I am trying to keep things general through the use of a ...
153 views

### Defining a matrix with elements acting as operators

This question is directly related with my previous one. I'll try to be more specific here. I have a matrix {{a[x],b},{c,d}}, where ...
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### What is this function aimed to do? [closed]

Table[Sum[tmatrix[[i, j]], {i, 1, 2}], {j, 1, 2}] apparently creates some sort of a table, and it evidently works on a matrix....although it is hard for me to understand what should it do beyond ...
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### Scan over regions of parameters

I have a function f which takes three arguments x, y and z: f[x_,y_,z_] := 2 x + 0.5 y + z ...
534 views

### Problem with FindRoot applied to functions

I am having difficulty with the error "is not a list of numbers with dimensions..." when using FindRoot (and other numerical routines in Mathematica) to solve equations numerically when the argument ...
43 views

### Is there any point to using a variable as a function parameter?

Normally one only sees patterns as function parameters: fun1[x_]:=x^2 Is there any point to using a variable in a function definition: ...
118 views

### Function does not execute commands and fails to evaluate [closed]

The code I am trying to execute: hh[x_, y_] := x + y; hh[{3, 4}] The expected output: 7 However, on output I get ...
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 ...
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: ...
111 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 ...
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### 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 ...
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 ...
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### Extra restrictions in best response functions using Manipulate[ ]?

I have two best response functions that I have defined like this: ...
35 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 ...
128 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} ...
107 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 ...
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 ...
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 ...
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....
35 views

### Which the functions of parameters can use Span [closed]

As I know,ImageValue,PixelValue,ReplaceImageValue,...
67 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 ...
38 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? ...
66 views

### Plotting a function of another function

Edit: So I have several functions which come from other functions. For example: ...
85 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: ...
70 views

### Plotting function described by other functions!

I want to plot and manipulate my VS function which comes from the other functions above it. So, what should I use in order to draw my function considering that it is described by other functions. I ...
140 views

### Implicitly inverting a function from numerical solution [closed]

I have the following piecewise continuous function: ...
67 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 ...
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 ...
71 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" ...
138 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. @@...
119 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 ...