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

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0answers
83 views

Find eigenvalues without filling the matrix

Is it possible to find eigenvalues of a matrix without filling it? The matrix elements are given by a known function f[p1,p2]. This is relevant for a matrix too ...
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1answer
68 views

Get subgraphs: communities of graph g

I have a graph g. I want a set of graphs c which holds the community subgraphs of g. I ...
2
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1answer
141 views

Why evaluation doesn't fail if arguments are invalid? [duplicate]

Sorry for a noob question, but this is something that I wonder about each time I work with Mathematica. Coming from standard programming languages (Python and Java), I expect my functions to fail ...
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1answer
122 views

How to study the sign of an expression including a function, with conditions on the function?

I'm trying to study the sign of an expression, having information on some of my parameters. I don't know how to code these conditions. For example, I want to know when this expression: ...
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1answer
91 views

Sort lists of vertices {indegrees, outdegrees} by indegree

in = VertexInDegree[F]; out = VertexOutDegree[F]; I want both in and out to be ordered by in. Example: graph has nodes a,b,c with indegrees 1,2,0 and outdegrees ...
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1answer
113 views

Defining arbitrary order derivatives function [duplicate]

I have a function $\phi(t)$ and I want to define a function $\phi D(t,r):=\phi^{(r)}(t)$, in other words evaluate the $r$'th derivative of $\phi$ at $t$. The naive code that I have is: ...
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1answer
54 views

Replicability of RandomVariate within a function?

I have a rather basic question but can't figure out a foolproof answer. In the following code, I build a function which returns the mean difference between successive elements of a vector created from ...
0
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0answers
31 views

Table of values for functions with random variables [duplicate]

I'm trying to get a table of values for functions with random variables. First of all, i have a function like that: ...
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1answer
83 views

Problems with For statement

I'm trying to iterate some expression through for loop: ...
0
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0answers
116 views

Financial Derivative european call option

When estimating financial derivatives like a european call option there is a parameter named: dividend paid per time unit. What does this mean, I have not been able to find any more information about ...
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1answer
182 views

Mapping a function over n levels

I want to map a function over a matrix of rank n, for example: ...
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3answers
524 views

Testing for continuity over a given domain

Is there any way to use Mathematica to test whether a function is continuous over a given domain?
0
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0answers
220 views

Solve function doesn't work

I have the following system of equations that I need to solve: ...
2
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0answers
113 views

A math function similar to “LatticeReduce” for finding linear independent basis

We would like to ask a math function similar to "LatticeReduce" for finding linear independent basis. The input is a list of vectors $M=\{v_1,v_2,v_3,\dots\}$, with the following property: There is a ...
1
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1answer
78 views

Compose two special power series expansions

I have two functions $A(x), B(x)$, given in a special power series form: $A(x)=1-x^{2}\left(\frac{a}{10}-\sum_{k=1}^{9}b_{k}\left(\frac{(x^{2}-1)}{r}\right)^{k}\right)$ ...
4
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4answers
265 views

Speed up replace all

I have large list of rules, I would like to use list/.rule, but assume that rule is a set of rules rule 1, rule2 rule...I want ...
1
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1answer
130 views

Time Varying Payoffs?

I'm trying to write some code that will return the final value of an annuity whose monthly payouts may or may not be constant each month. Right now I have working code for constant payments, but I'm ...
2
votes
1answer
317 views

ListDensityPlot

In Mathematica help it's written that: ListDensityPlot[array] -> generates a smooth density plot from an array of values. ...
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1answer
123 views
1
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1answer
200 views

How to define a list that contains all primes less than x?

how can I define my own list in which I have all primes less than x?
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3answers
85 views

Half kth term if n is even and k=n/2?

I am trying to write a function which will perform the equation in the attached image. So far, I have: ...
2
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1answer
163 views

Discontinue, then continue x-axis of 2D Histogram

I have the pictured Histogram. It was generated by the following lines: ...
0
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2answers
985 views

How to find number of connected components of graph G?

Is there a command that can count the number of components of a graph, in the same way that VertexCount[G] counts vertices?
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0answers
18 views

Using functions as input for a function - won't simplify [duplicate]

I've defined a function P[k_] := 1/[Sqrt]2 (R[k] + L[k]) where R and L generate matrices. However the output of this function never full simplifies (even when I use the Simplify[%] functions). It ...
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0answers
527 views

Derivative of the Absolute Value Function in Mathematica looks very different from the actual answer

Derivative of the Abs Function in Mathematica looks very different than the actual answer. Why? How to correct this? For example I entered ...
1
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1answer
85 views

FlipView Alignment problem

Here's the problem with MWE: Framed[ FlipView[Framed /@ {100, 1}, Alignment -> Center] , ImageSize -> {100, 150}, Alignment -> Center] I ...
2
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1answer
147 views

A question about definite integrals and timing

I need to integrate the expression G given below: ...
0
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1answer
86 views

Blank plot that shows up briefly when changing plot options

I wrote some code in Mathematica to calculate and plot, in tw0 different ways, a function depending of two variables. But the plots are empty even if it takes a few minutes to evaluate the plot ...
2
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0answers
66 views

Complicated output from simple Eigenvalues problem

I have code that uses Eigenvalues on matrices of various sizes. But the output of what should be a very simple problem, namely finding the eigenvalue of a 1x1 matrix, is overly complicated. ...
3
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2answers
417 views

Manipulating slots in a pure function

How does one manipulate the slot numbers in a pure function? Some trick with Evaluate or Hold? I'm aiming for something along ...
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0answers
43 views

Verify “Type” of solution [duplicate]

I've written some Mathematica functions which allow the user to verify if a mathematical function has certain properties. What I'm basically doing is generating "random" functions in respect of ...
3
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2answers
440 views

How to copy a function by value?

I need to change a function symbol multiple times by assigning another symbol to it, but when I'm trying to do that the symbols overwrite each other. I'm assuming this is because the assignment is by ...
0
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1answer
81 views

nested series expansion

I have to invert the following matrix in which the functions U[t,x,y,r] and K[t,x,y,r] and all their derivatives are "small"; ...
1
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1answer
82 views

Selection of the position of the variable

I defined a function funloglogplot to make a loglogplot of a function (function1) depending on several variables ...
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0answers
26 views

Minimizing roots of a transcendental equations [duplicate]

I'm trying to use the solution of FindRoot with parameters for further calculations. Annoyingly enough it always gives me trouble with replacing the parameters. As an example I'm attaching a simple ...
0
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2answers
246 views

How to find intervals in the domain corresponding to intervals in the range?

I want to find the intervals for the argument m1 of this function corresponding to the value for the function lying in given intervals of the range: ...
0
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0answers
57 views

Fold Dynamic Function [duplicate]

I'm making on a demo working with differential equations as functions of two variables (x and y). The demo will have to Fold the differential equation with an initial y-value and a series of x-values. ...
0
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1answer
124 views

A problem with set values

The following code is just an example to clearly explain my problem. Assume that : ...
0
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0answers
307 views

A problem with functions and Infinite expression 1/0 encountering

Following code (function) makes integrals and then replace f[x] with Cos functions and calculate the definite parametric ...
1
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2answers
224 views

How to apply function f for each time value t, to each pixel from image, resulting in t images

I have a 2D array of complex values and I want to apply a function to every entry of the array, for every timepoint t in a list. I know how to apply my function to one entry for every time t in a ...
3
votes
2answers
340 views

Need to create a function to generate all permutations of Range[$n$] [duplicate]

Basically I need a function that takes a list and gives all the possible permutations of it. The reason I can't use Permutations is that I have to apply another ...
1
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1answer
108 views

What is happening in Map[Function[x, x^2], a + b + c] from the Pure Function tutorial

The Pure Function tutorial gives an example: Map[Function[x, x^2], a + b + c]. I would expect the output to be (a + b + c)^2, ...
5
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2answers
408 views

Understanding Transpose

It is very likely that it is my lack of math skills that is showing up here. However, I think Transpose is such an important function that I need to master it. So I ...
3
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0answers
61 views

Can BreadthFirstScan be modified?

I would like to obtain a "slick" implementation of A*-search algorithm on Graph objects, using the built-in BreadthFirstScan (if that is possible at all). I noticed that BreadthFirstScan is static in ...
2
votes
1answer
223 views

Dynamically Updating Function

I use Mathematica 8 and am working with DynamicModule. I'm trying to enter a function in an InputField then later apply it to two values entered in subsequent Input Fields. The function just does not ...
1
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1answer
108 views

Problem with System`Graph and Combinatorica`Graph functionality conflict

I'm trying to generate a random geometric graph. When evaluating HighlightGraph, even if I am passing graph object Mathematica always gives error like A graph ...
11
votes
4answers
966 views

Moving the location of the branch cut in Mathematica

According to the documentation, Mathematica chooses the branch cut for $\log(z)$ to lie along the negative real axis. It it possible to change this so that it lies along the positive axis or elsewhere ...
6
votes
2answers
297 views

Binomial[-1,-1]

According to various sources e.g. http://www.proofwiki.org/wiki/Definition:Binomial_Coefficient and Wolfram themselves http://functions.wolfram.com/GammaBetaErf/Binomial/02/ , the binomial ...
8
votes
3answers
419 views

How to protect functions in a Mathematica Package?

I'm writing a Mathematica Package with many functions, but only two can be seen/public. I have: ...
1
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1answer
168 views

Is there a function for falling factorial in Mathematica

If I had to construct a function for falling factorial in mathematica I'd do something like that (hope I'm not mistaken): fallfact[x_,k_]:=$\prod_{j=0}^{k-1}(x-j)$ But is there a built-in ...