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

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6
votes
2answers
148 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
154 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
288 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
235 views

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

I tried this code, which downloads data from several weather stations. ...
0
votes
1answer
400 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 ...
1
vote
1answer
206 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
45 views

StringLength function [duplicate]

allWeatherStations = WeatherData[]; fullformStations = FullForm /@ allWeatherStations; Tally[StringLength /@ fullformStations[[All, 1, 2]]]. This code not working. ...
-1
votes
1answer
152 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
2k 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
63 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
143 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 ...
4
votes
0answers
88 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
205 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. ...
1
vote
2answers
513 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 ...
16
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 ...
1
vote
1answer
97 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
174 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
90 views
0
votes
1answer
92 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
96 views

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

in the document of HoldAllComplete, it says: Evaluate cannot be used to override HoldAllComplete.. for example, when I'm ...
0
votes
1answer
44 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 ...
23
votes
1answer
507 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 ...
1
vote
1answer
119 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: ...
1
vote
1answer
86 views
0
votes
1answer
88 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
86 views

Maximise output issue

When I execute the following command, I get a numerical output as follows: ...
1
vote
3answers
186 views

How to calculate time period?

I have the starting and ending dates and times. And I need to calculate the night time in this period (from 10 pm (22) to 6 am (6)). Example: starting date and time is {2015, 1, 4, 3, 10} ending date ...
6
votes
4answers
376 views

What is shorthand way of Reap list that may be empty because of zero Sow

Sometimes because of conditionals, you cannot guarantee that Sow will be called at least once. Reap[Sow[1]][[2,1]] results in ...
0
votes
0answers
39 views

Procedure argument value change [duplicate]

I'm trying to create my own hamiltonian cycle algorithm using Mathematica for school, and I'm stuck on a syntax issue. I get the following error: ...
1
vote
0answers
62 views

Improving RationalInterpolation Result

The following code produces a {4,4} rational interpolation approximation accurate to 10^-6 or better over the range ...
1
vote
3answers
66 views

Define a function of a vector without fully specifying the components of the vector [duplicate]

I have a vector $A=\{1,2,3,4,5,6\}$, and I want to define a function of $A$ as f[A_]:=A.X where $X$ is another vector. I want to define this function without ...
0
votes
0answers
48 views

How to make Piecewise continuous [duplicate]

I have a function defined by its slope in a continuous sequence of intervals, e.g. ...
0
votes
1answer
73 views

Codes for the derivative of a random polynomials

Good day! Please, I need some help here, I used this codes ...
2
votes
3answers
199 views

Simplify a composition of functions

How do I make Mathematica simplify, for example, (1-#&)@*(1-#&) into #&? ...
1
vote
2answers
409 views

Minimizing the largest difference between two functions

I have two functions defined on the same domain, $f(x)$ and $g(x)$ where $x$ is in $(0,1)$: f[x_] := (-1 + x) Log[1 - x] - x Log[x] g[x_] := Log[1 + 2 (-1 + x) x] ...
0
votes
3answers
134 views

How to define a function

How can I define a function which depends on a function of x? Something like this f[u[x]_,u[x]']= u[x]' + a [x] u[x] +b[x] I think I wasn't enaugh clear. If I ...
3
votes
2answers
152 views

What's real analogue for FromDigits?

FromDigits only works for integer strings. What's its real-number analogue?
2
votes
2answers
168 views

How to apply list of values to a list of functions

I have the following: first= {1+a,2+a,3+a,4+a} and a list t={0,1,2,3} I want to evaluate the first element of "first" at ...
0
votes
3answers
113 views

Using Solve to obtain a constant so that f(x) is continuous at x=2

I need to solve for c such that the function is continuous at x=2. How do I do this automatically? I have expressions for ...
2
votes
1answer
87 views

How to package a function for export?

I often post code for functions on Stack-Exchange, and then later find that they are unexecutable - that people can't use them because I mistakenly omitted some private functions or values that are ...
5
votes
1answer
84 views

Using a progress bar in a functional expression

If we have a procedural construct like a Do loop or Table, it is straightforward to make a progress bar to indicate the percent ...
0
votes
1answer
118 views

how to download using weather data function many proporties exactly.

how to download using weather data function many proporties exactly. Example WeatherData["WMO44292", "Humidity", "Pressure", "Temperature", \ {{2005, 1, 1, 0, 0}, {2015, 1, 1, 0, 0}}] .
2
votes
2answers
93 views

NotebookWrite in EvaluationBox forces Input CellStyle

There is a promissing new function EvaluationBox[] and a nice last example in documentation section for it: ...
1
vote
1answer
51 views

How to change time zone for all outputs? [closed]

How to change the time zone in Mathematica for all functions returning a date or time?
3
votes
1answer
92 views

How should I define functions that distribute over Plus?

I have a linear function which also follows the chain rule (it is a derivation), so I defined it recursively, following a Wolfram tutorial (which I've misplaced) and other related answers: ...
2
votes
1answer
448 views

Working with derivative of conjugate of a complex number

I have a complex function, lets say $g(x)$. I want to take its and its conjugate's derivative. I need the solution of derivative which must be symbolically and computationally efficient. Lets take an ...
3
votes
1answer
413 views

Weierstrass function

I am trying to create plot of the Weierstrass function in Mathematica. I wonder if it's possible, when I define this function as ...
1
vote
1answer
119 views

FunctionDomain doesn't work with If

When I call FunctionDomain for function defined by a formula with If, for example ...
1
vote
0answers
75 views

How to simplify an expression with a radical sign nesting in a radical sign

Is there a function can simplify an expression with a radical sign nesting in a radical sign in Mathematica? I use V9. RatDenmon is a function that can ...