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

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0
votes
0answers
291 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
vote
2answers
218 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
319 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
vote
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
votes
2answers
397 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 ...
2
votes
0answers
58 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
215 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
vote
1answer
105 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
937 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
291 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
407 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
vote
1answer
161 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 ...
2
votes
1answer
151 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 to ...
3
votes
1answer
197 views

Put random points into a specific 2D subregion

I want to cover a particular subregion of the x-y plane with a random distribution. As this particular region is not a circle I encounter some problems declaring the permitted zone where to put ...
3
votes
3answers
213 views

Finding a better way to define a matrix

I first defined a 171x171 matrix containing only zeros and then replaced 18 specific rows with nonzero entries. The other $153$ rows will be average of $2$ of the existing $18$ rows. Rows $2$ ...
1
vote
2answers
339 views

Given an equation with one parameter, how do I use NSolve to solve it for many values of the parameter?

I was wondering if there was a way to use the Mathematica NSolve command to solve an equation that has a parameter with various values. An example of which is: ...
1
vote
3answers
190 views

How to update a list in a function in each iteration

There is a list with numbers 1 to 8 ( p1 ) and another list (j) which contains 4 numbers which shows different 4 positions of ...
2
votes
1answer
133 views
-1
votes
1answer
114 views

Transformation of a simple logic statement

I'm designing a logic circuit and I was wondering if the following two things are equivalent: (x <= y) and (x < (y + 1)) I can't think of any set of numbers that would make these two things ...
0
votes
0answers
64 views

For loop efficiency [duplicate]

What is a more efficient way of solving this problem? By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms. ...
10
votes
5answers
383 views

Transform a list of functions to a composition

How do I apply a list of functions in a nested way? Example: functionList = {f1,f2,f3} RequiredCommand[functionList,Pi] such that the required command returns ...
0
votes
1answer
60 views

How to put some values from a list into a function in a Do loop

I want to program a code in MATHEMATICA in order to calculate some values in different iteration. For example, assume this list: list={1,2,3,4,5} Now assume that ...
1
vote
2answers
137 views

Avoid making repeated Random Integer in different iterations

Assume following code : Do[ i1 = RandomInteger[{1, 5}]; i2 = RandomInteger[{1, 5}]; While[i1 == i2, i2 = RandomInteger[{1, 5}]] , {k, 1, 4}];` This ...
7
votes
1answer
580 views
27
votes
5answers
2k views

Are there “All” and “Any” functions in Mathematica?

In Python, there is a function all which returns true if all of its arguments are true, and any which returns true if at least ...
1
vote
2answers
627 views

How to evaluate Modules in a notebook from another notebook?

I would like to create a notebook populated with several modules and be able to evaluate these modules by running a separate notebook. I have attempted several uses of the ...
1
vote
2answers
204 views

Plot a function which depends on itself

How can I plot a stepwise function like f[a, t] = 10 Exp[-0.1 Sin[t]] for a > t and ...
4
votes
2answers
269 views

DynamicModule/Dynamic CheckboxBar Slow for Large Lists

I am trying to create a dynamic construct that takes a large list of expressions and allows the user to interactively select any number of entries for further manipulation. This is what I have ...
0
votes
1answer
123 views

Normalize equation in NDSolve?

I have numerically solved and plotted the solution to the Mathieu equation using NDSolve successfully, as below: ...
1
vote
0answers
54 views

Panel size undesired behaviour

This is next question from the series: better avoid Panel if you care about details. previous about FrameMargins In the ...
0
votes
1answer
103 views

Evaluate integral of a series

I want to evaluate this integral, but it won't work. Does anyone knows why? ...
0
votes
0answers
186 views

Intersection of any triangle with a circle in Cartesian coordinates

I started a notebook dealing with metrics in a triangle and its intersection points by a circle. Up to know I reached the point of having plotted a triangle, a circle with an arbitrary centre and I ...
4
votes
0answers
114 views

“Off-label use” of Mathematica functions for performance

Assisting an acquaintance with a simulation where a very large number of binomial probability calculations are required, I pointed them to a slightly obscure function to dramatically speed up their ...
1
vote
2answers
113 views

How to work with lists of functions

I have some lists of interpolated functions and I want to know if there is an easy way to operate with them. A simplified example: ...
0
votes
1answer
88 views

Working with functions

I am required to write a function that takes a function as a parameter. ...
1
vote
0answers
44 views

How to apply an rule to factors matching a certain form

Suppose we have many expressions involving irrational ArcTan expressions (such as ArcTan[Sqrt[3],5]) along with other irrational factors (such as ...
3
votes
1answer
86 views

How to apply RootLocusPlot corectly

I have to analyze the complex regions of variable c which is define obtained with InverseLaplace help in the form ...
0
votes
2answers
169 views

How can I improve Do loop?

I have very large input of time series data (over 30000 observations) that look like as follows: ...
0
votes
1answer
98 views

How to define a function that operate with a base case recursively? [duplicate]

Let's start from the simplest case: say I have a function $f(x)=x$, and let's say I want to define a new function (of $x$) to be its $n$-th power $(f(x))^n$. How should I write the code? I tried: ...
3
votes
2answers
511 views

Differential operator squared

I defined a one-dimensional momentum operator $\hat{p}=-i\hbar\frac{\partial}{\partial{x}}$ in Mathematica p = -I * h * D[#, x]& and I want to get the ...
2
votes
0answers
93 views

Are there some other ways to solve a second PDE except DSolve?

I have a partial differential equation as follows: $$\frac{\partial p(x,t)}{\partial t}=\text{Dp} \frac{\partial ^2p(x,t)}{\partial x^2}-\frac{p(x,t)-\text{p0}}{\tau }$$ What I try to do was to get ...
0
votes
0answers
112 views
3
votes
1answer
148 views

Arguments for ChartElementFunction

I was reading the documentation for BubbleChart and I saw this example ...
0
votes
3answers
172 views

How to combine multiple functions into a single function, indexed bya new argument

I have a system of expressions (matrices) which correspond to increasing orders of precision in a theory. These expressions are quite complex (require about 40+ lines of code to produce) and are not ...
1
vote
0answers
343 views

Slow mixture fitting when having ill-conditioned covariance matrices. How to make it faster?

I'm using Mathematica 9.0 to fit multidimensional observations with a gaussian mixture. To do so I first adapted these steps to ensure that the mixture parameters are well defined (see ...
5
votes
2answers
540 views

Multiply each element of an array by another array?

I would like to multiply an array by each element of another array, and am having a lot of trouble finding a built-in or automated method of doing. Here is an example of what I'd like to achieve: ...
1
vote
2answers
260 views

Using Array Elements as Function Arguments

Suppose I have an array p = {a,b,c,d} and a function f that takes a variable number of arguments. I want to evaluate ...
0
votes
1answer
95 views

Can I make a function which depends on several arguments which are not independent?

Here's a simple example Suppose have the permanent relation that z is proportional to xy^2, for real numbers s. z = s x y^2 Now, we are interested in ...
0
votes
0answers
29 views

Problem with slot in If statement [duplicate]

I am struggling with slots, In this case I have a function int which gives either true or false. When it gives true, I want ...