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

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1
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1answer
147 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
1answer
98 views

Understanding `FixedPoint`

I understand that FixedPoint[(# + 2/# )/2 &, 1.] can be written ...
0
votes
0answers
24 views

Fibonacci series up to 300 terms [duplicate]

I tried to generate a list of Fibonacci numbers up to 300 terms and gets a runtime error. f[0]=0; f[1]=1; f[x_]:=f[x-1]+f[x-2]; Table[f[x],{x,1,300}] Is there ...
0
votes
1answer
50 views

Question about a catalytic equality?

I have a question on math.SE that explains how I came up with these equations. ...
0
votes
1answer
53 views

Creating Function with String Input

I am trying to create a function that needs to transform the input into a string. The objective is transforming a latex input into a calculable mathematica expression. ...
-2
votes
3answers
61 views
3
votes
1answer
65 views

Why minimization does not work with symbolic array as arguments

If I try to minimize with constraints a function of several variables, with Gamma regularized function involved in the constraints it seems to works, as shown below (this is just a dummy example ...
-3
votes
2answers
79 views

Random Polynom Plot [closed]

I should write a module "RandomPolyPlot[n, amin, amax]" which calculates all roots (nulls) of a n-th degree polynomial function. Then I should illustrate it on the complex plane. I also should ...
1
vote
2answers
63 views

How to stop FullSimplify from returning Root objects

I have several expressions in a series, such as 1/4 (-(1/4) + Sqrt[5]/4 + I Sqrt[5/8 + Sqrt[5]/8]) (-1 - Sqrt[5] + 2 Sqrt[7/2 + (5 Sqrt[5])/2]) If I run ...
-3
votes
2answers
76 views

Write a function, write a pattern [closed]

I have the following list: list = {{1, 2, 4}, 6, 7, 8, {8, 2}, {3, 4}, {4, 5}, {1, 2, 3, 1}}; (a) I should write a predicate-function in combination with an ...
0
votes
0answers
27 views

Why don't we use SetDelayed when we use placeholder to declare a function? [duplicate]

On the answer of http://stackoverflow.com/questions/4272067/what-does-mean-in-mathematica Typically when we declare f(x)=x^2 function, it is: f[x_] := x^2 But ...
0
votes
0answers
40 views

How can I put the results of TrigReduce function into a more convenient form? [duplicate]

a1 D11 Cos[n x] + a0 a1 D11 Cos[n x] + 1/2 a1 a3 D11 Cos[n x] + 1/2 a2 a4 D11 Cos[n x] .......for example this expression can be written like ('expression') * ...
6
votes
2answers
87 views

Optional arguments with lists as function parameter

I'm developing a function f which should support optional arguments {x_, y_} in list form. A simple example looks like this: ...
2
votes
1answer
98 views

How to run code in a saved file when it is opened

I have a Mathematica file that I saved. In it, I have multiple functions that I've defined and have evaluated a number of the functions with different arguments. I would like to be able to open the ...
1
vote
1answer
62 views

Defining a Function

I've been reading about functions in Mathematica and playing with this for hours, but I'm clearly missing something. The following code correctly calculates "fail", the number of failed scenarios. I ...
1
vote
1answer
102 views

Create a function with Dt[x] as a variable

I have a function (for example F[x_]:=Cos[x]). I want to define a function like Fdot[x_,xdot_]:=Dt[F[x]] where xdot represents Dt[x]. For example, to define Fdot one might naivley try ...
2
votes
1answer
105 views

How do I download and export data from many weather stations?

I tried this code, which downloads data from several weather stations. ...
1
vote
0answers
25 views

Import names into notebook namespace

I have function that at some point has list of strings (e.g. {"apple","pear"}) and I want to declare (initialize) those variables in notebook namespace to default value (e.g. 0) so I could execute in ...
0
votes
1answer
57 views

How can I use nonlinear model fit with multiple variables? [closed]

I have a data set with four entries. the first three entries correspond to variables in the fit x,y, & z. The fourth entry corresponds to the function value. I am trying to fit this data to a rate ...
0
votes
1answer
52 views

How to properly use conditionals inside NDSolve

Currently I am working with Mathematica to learn the program, and I'm confused what exactly is wrong with this code. ...
0
votes
0answers
44 views

StringLength function [duplicate]

allWeatherStations = WeatherData[]; fullformStations = FullForm /@ allWeatherStations; Tally[StringLength /@ fullformStations[[All, 1, 2]]]. This code not working. ...
-1
votes
1answer
120 views

need help to price a european option using finite difference method [closed]

I am writing a function to price European option using backward induction finite difference method. The function is expected to price a European option taking Stock (stock_), age (time_), volatility ...
19
votes
5answers
1k views

Moving maximum function?

How can I construct a moving maximum function? For example, if I have a list of 12 values: { 5, 6, 9, 3, 2, 6, 7, 8, 1, 1, 4, 7 } and I want to maximize over 3 ...
0
votes
1answer
49 views

Replace element of matrix based on rule which invloves other element of same matrix

I am trying to replace 1s row of matrix d iteratively from right by multiplying last element in 1st row with (1-int*dt) to generate 2nd last element. The replacement continues till I reach the 1st ...
4
votes
2answers
117 views

Coarse-graining in numerical integrations

I have been working recently in a coarse-graining problem I found when using NIntegrate: I am trying to evaluate the function $$f(a)=\int_0^{\infty}x\,e^{-(a^2+b^2)x^2}\text{d}x$$ numerically as a ...
0
votes
0answers
54 views

How to replace a part of array based on certain rules which involves usage of other array

I am trying to replace outermost column of array "fd" in below code. fd is matrix of dimension (nas1,nts) which is initially filled with 1. I want to replace outermost column of fd with result of Max ...
2
votes
0answers
45 views

What is the difference between GenerateDocument and TemplateApply[NotebookTemplate[

Abstract GenerateDocument[ _NotebookObject ] seems to do the same what TemplateApply[ NotebookTemplate @ _NotebookObject ] ...
4
votes
0answers
83 views

Using an external Pattern breaks Format

I noted while writing this answer that using an external Pattern on Format doesn't work: ...
1
vote
2answers
154 views

How can I create function which contains an ODE system and its numeric solution?

I have created a function like the following, which contains an ODE system. And I want to know the effect of different parameters. ...
0
votes
2answers
171 views

FindShortestTour to solve Traveling Salesman Problem

I'm trying to write my own code to find the shortest route but I'm lost on how or where to start. Does anyone have any idea how the FindShortestTour function works? What type of algorithm or structure ...
9
votes
1answer
300 views

solve ODE with divergencies

The solutions of the second order differential equation $$\frac{1}{\eta}\frac{d}{d\eta}\left(\eta \frac{df}{d\eta}\right)+\left(1-\frac{s^2}{\eta^2}\right)f-f^3=0$$ is shown in Fig. 5.2 below, for ...
15
votes
6answers
1k views

Will Version 9 functions all work in Version 10?

Having developed a substantial code base in Mathematica 9, leads me to ask these important questions prior to downloading and installing Mathematica 10. Will any Mathematica functions from the ...
21
votes
3answers
806 views

DeleteDuplicatesBy is not performing as I'd hoped. Am I missing something?

Déjà vu: a new-in-v10 function should provide a better solution to an old problem, but my enthusiasm is curbed when I run timings. This time the function is ...
1
vote
1answer
70 views

How to Reap data from a ScheduledTask?

Here is an amusing little function mapped over a range just to iterate it. It ignores its argument and works entirely by side-effecting a global variable: ...
3
votes
1answer
157 views

How do I create an array by applying a function to the index of each element?

I am looking for something like matrix(m, n, f), but for Mathematica rather than MuPAD, and for arrays rather than matrices. That is, I'm looking for a(n ...
2
votes
0answers
44 views
39
votes
2answers
4k views

What is so special about Prime?

When we try to evaluate Prime on big numbers (e.g. 10^13) we encounter the following issue : ...
0
votes
1answer
84 views

Can we say that “all functions in Mathematica are some kind of pattern-matching-and-replacement procedures”? [duplicate]

Currently I am studying Mathematica programming, and when I study pattern matching and replacement, I find it is quite similar to functions. So can we say "all functions in Mathematica are some kind ...
1
vote
0answers
75 views

How can I use L.Shifrin s code formatter package better

in the document of HoldAllComplete, it says: Evaluate cannot be used to override HoldAllComplete.. for example, when I'm ...
0
votes
1answer
38 views

How to have default case in Which? [closed]

Saying we have a function: a[x_] := Which[x === 1, "AAA", x === 2, "BBB", _, $Failed] How can I make this function to be equal to ...
22
votes
1answer
431 views

Why does list assignment with a packed array result in unpacked values?

Bug introduced in 5.2 or earlier and fixed in 10.1.0 This is another question on the design choices in Mathematica. I understand that without direct reply from the developers it may not be ...
7
votes
2answers
107 views

How to create a dynamic expanding DisplayForm's styled like the ones in v10?

The display forms for objects like ClassifierFunction are nice clickable boxes I like this, and now I'm trying to create my a custom version of this for my ...
1
vote
1answer
97 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: ...
11
votes
1answer
187 views

Compability between Graphics coordinates and shifted projections in GeoGraphics

Edit 27.01: Confirmed bug. V. 10.0.0 - V. 10.1.0 I'd expect GeoGraphics to handle positions of points since they are provided ...
3
votes
1answer
56 views

LineScaledCoordinate problem for exact coordinates

Edit: Confirmed bug. CASE:2326540. Still the case in V 10.1. Solution: Wait and use N meanwhile. I've faced this problem ...
0
votes
1answer
73 views
0
votes
1answer
220 views

mathematica apply list of functions to the same arguments [closed]

EDIT: "Through" is partial solution, because it cannot be used in expressions, where these functions are used without arguments. How can I apply list of functions to the same arguments? e.g. ...
0
votes
1answer
62 views

Calculating functions of sounds

I've seen that it is possible to create a sound from functions: Sound[{Play[Sin[1000 t (1 + t^2)], {t, 0, .2}], Play[Sin[500 t (1 + t^3)], {t, 0, .5}]}] Is is ...
6
votes
2answers
68 views

Maximise output issue

When I execute the following command, I get a numerical output as follows: ...
10
votes
4answers
3k views

How can I differentiate Numerically?

Mathematica has two ways to integrate: Integrate and NIntegrate. But what about D? ...