For questions on writing functions (pure or using Set/SetDelayed) for any purpose, including the features that may be incorporated in those functions, such as options, patterns and conditions.
3
votes
1answer
78 views
Using NestWhileList to determine smallest prime value in series
I have a function recursively defined as follows:
$a_{n+1}-1=(a_n-1)\times lpf(a_n)$, whe $lpf(x)$ is the least prime factor of $x$.
Now, given an initial value of $a_0$, I would like to find the ...
4
votes
1answer
112 views
Module with “local functions”
I am trying to use a Module having "local functions", i.e., those which I need to define only inside this module.
So I tried this:
...
4
votes
3answers
96 views
Creating a nonperiodic function in mathematica
I want to create a non-periodic square wave with values of 1 and -1(not necessarily alternating).
For e.g. I want to convert an arbitrary array like {1,-1,-1,1,-1,1,-1} into a function.
I tried ...
1
vote
1answer
66 views
Confirming the existence of a function related to a matrix
Is it possible to get an answer to the following question in Mathematica?
Let $M$ be a $n$ by $n$ matrix, is there a function $m:\mathbb{N}\times \mathbb{N}\rightarrow \mathbb{Z}$ such that ...
0
votes
1answer
80 views
How could we define a function recursively?
Let us first consider the constructon of the following simple iteration
...
3
votes
1answer
112 views
Downvalues vs. Scoping for Functions
Regarding my recent question on using a default value for a function argument when a pattern was not met yielded some interesting answers, but the general consensus was "Yes this can be done, but ...
0
votes
1answer
164 views
How do I make function A create and return function B?
My basic need is I have to take lots of data and other information and assemble it into a function (static parameters). I then need to call the function many times for numerical results for many ...
2
votes
2answers
112 views
How to achieve Set+Part like behaviour in custom Set function?
So I've been toiling away on my DataFrame package. I've been trying to get Set to work with it, but it seems it either can't be done (ie via ...
1
vote
1answer
105 views
Creating an array eval [closed]
How can I create an one dimensional array (a vector) evaluating a function of two variables? I know how to do it with one variable:
Array[f, n, {a, b}] generates a ...
10
votes
1answer
109 views
Multiple templates for a single user-defined function
How do I use the ::usage tag to allow the Mathematica v9 front end to know that there are multiple ways to call an overloaded function (a function that can have ...
3
votes
1answer
88 views
Is it safe to assign a variable and function of the same name for different things?
I'm writing out a notebook that goes through the van der Waals Equation of State for gases, and I run into a situation where I want to assign (simplified) Tc[b_]:=5b, use that to solve for b in terms ...
0
votes
1answer
271 views
How can I make a plot of the Higgs potential?
I was wondering, how would could I make a drawing of the Higgs potential aka "mexican hat potential". I am quite new to Mathematica and don't know where to look to learn how to implement such a ...
6
votes
4answers
172 views
Function argument to default under certain condition
Inspired by this and this question (and how I handle this in practice), what is the best way to default a function value when a certain condition is met?
For example, if a function is defined as:
...
2
votes
1answer
104 views
Can my permutations function be defined using iteration?
I have two functions, tuples and perm. They are similar.
...
2
votes
0answers
60 views
From notebook,how can I change variable value with in .m file dynamically?
I wrote a function named Testing.
...
3
votes
2answers
109 views
Apply UpValues before Listability
I'm trying to modify Plus but am running into trouble with it being Listable:
...
3
votes
1answer
67 views
Values set using SetOptions are staying in the kernel, beyond the necessary time [closed]
I wrote a function name as functionTest and also mentioned default Options.
...
6
votes
1answer
267 views
How can I define a function that can accumulate its parameter?
For example, write a function add:
add[3] return 3
add[4] return 7
add[10] return 17
10
votes
2answers
200 views
Functions that remember their values
Can someone explain what is going on with the following ...
func[y_] := func[y] = (Print["Hello world !!!"];)
func[1]
Hello world !!!
...
1
vote
1answer
135 views
Fitting parameters of user defined function returning discrete values
So, I'm fairly new to Mathematica (apologies in advance for the noobiness), and I'm having some problems regarding fitting the parameters of a user defined function to data. I'll give a representative ...
0
votes
1answer
135 views
How to write case, in piecewise function, correctly [closed]
I want to plot graph of this piecewise function in Methematica:
$f: [0, 1] \mapsto \mathbb{R} $
$f(x)= \begin{cases}
\frac{1}{x - \frac{1}{3} } & \text{ if } x \in [0, \frac{1}{3}> \newline
...
6
votes
3answers
201 views
3
votes
2answers
207 views
Ways to plot interpolating functions more economically?
I am interpolating a lot of data over geographic coordinates obtained via GPS, and frequently I need to plot these interpolated functions together. For example, I may have an interpolated elevation ...
3
votes
0answers
43 views
How to influence Suggestion Bar in your package/code [duplicate]
Possible Duplicate:
Is it possible to customize the Suggestions Bar?
I have written a little code (like a minipackage) of different functions. In using my code, the user typically starts ...
0
votes
1answer
104 views
Creating Recursive Sequences
Quite a simple question, I reckon, however, even quite an extensive search hasn't helped me.
I want to define a recursively defined sequence that starts with defined ...
3
votes
1answer
124 views
Feedback on my Subscript code
I have written a code, and I need a little feed back..
I want to make the Subscript distributive across (1) addition and (2) multiplication to mimic short-hand for ...
1
vote
3answers
145 views
More than one expression in the Table[] command?
I would like to construct a Matrix using the Table[] command. The issue is that I would like to use more than one expression for it. What I need to obtain is something like this :
...
2
votes
2answers
103 views
Hiding certain user-defined functions in front-end autocompletion
I have written an elaborate code that contains a collection of functions for the user and a bunch of auxiliary functions whose existence I would like to hide away from the user. I've written my code ...
4
votes
2answers
153 views
Pattern matching repeated structures with named subexpression components
I am trying to write a function with a pattern that tests its arguments for a particular structure. But in that pattern I'd like to name a subpattern to make it easier to exract and operate on.
The ...
7
votes
7answers
495 views
Can my color function be written more simply?
The code shown below works well, but I think the pure function I'm supplying to the ColorFunction option could be more elegant. How can I simplify it?
...
0
votes
0answers
52 views
Enable syntax-coloring on user-defined function [duplicate]
Possible Duplicate:
Syntax highlighting for your own functions
I have defined a function myIntegrate that carries out a routine similar to Mathematica's ...
3
votes
3answers
98 views
How to identify patterns in a tensor-polynomial and replace appropriate symbol?
I want to write a function tensorReplace[input] that takes a tensor polynomial in $r_i$ such as $r_i r_j r_k+r_i q_j q_k +q_i q_j q_k$ , and replaces each monomial ...
2
votes
1answer
114 views
Rookie mistake in defining a function with Modules?
I can't figure out what's wrong with this piece of code. I'm trying to define a function that counts the occurrences of x, y and ...
7
votes
4answers
289 views
Is there a concise form of Which or similar conditional?
Suppose that I want to write a function fun that takes an Integer num as input, and returns ...
10
votes
0answers
127 views
func::usage needs to be run twice?
There is an annoying problem that I can't figure out why it's happening. I have defined a usage for a my function tensorA:
...
7
votes
3answers
133 views
How to set a TraditionalForm output for a symbol
How do I set a TraditionalForm output for a particular symbol/function?
In particular I would like my user-defined symbol ...
1
vote
2answers
157 views
Composing two functions in Mathematica [duplicate]
Possible Duplicate:
Composition of mappings not working as expected
I am new to Mathematica and I am having trouble defining a certain composition of functions.
Let ...
2
votes
1answer
87 views
How to override `?NumericQ`
I have a function myFunc which I is to be displayed cleanly if arguments are symbolic, but which can also be numerically evaluated. I do this by defining a ...
4
votes
3answers
167 views
Define an 'inner product' with AngleBracket
I want to define my own little 'Inner Product' function satisfying properties of linearity and commutativity, and I'd like to use the "$\langle$" and "$\rangle$" symbols to output my results. For ...
3
votes
1answer
107 views
Permuting indices to form fully symmetric tensor with repeated indices
I have written a function (version 8) that takes as an input a list of indices such as {i,j,k} and outputs a fully symmetric tensor function containing $p_i$ and ...
2
votes
0answers
73 views
How can this function's options be used in different places?
I wrote this function to make a ListPlot where the points are colored by a third argument.
...
1
vote
1answer
76 views
How do I define a function that, when given a list of parameters, plots a family of functions?
So far I've got this:
draw[a_, b_] := Plot[{f[a, b[[1]], x], f[a, b[[2]], x]}, {x, 0, 5}]
The function draw will be used like ...
4
votes
3answers
166 views
Defining functions with special cases
I'm trying to define a function myFunc with a special case:
myFunc[x_, y_] = (x^2 - y) Log[x^2 - y];
myFunc[x_, x_^2] = 0;
...
3
votes
2answers
123 views
How to create 'help' `?` for a function (as documentation)
I have defined a function PassVeltB in some complicated way. But now I would like to add a little documentation that gives the user information on how it is to be ...
2
votes
3answers
234 views
How do I construct a pure function to extract data fields from records that are strings?
How can I get from data segment format to the final segment format with a pure function? The data fields are fixed length. There are no separators between the fields.
a) list
...
1
vote
1answer
170 views
Combining two pure functions
How to get from the following intermediate result to the final one with just one pure function?
...
9
votes
2answers
197 views
Define Log so that negative reals evaluate on lower edge of branch
I need to get Mathematica to evaluate the logarithm of a negative real number using the lower branch instead of the upper branch, so that while
...
1
vote
2answers
128 views
Function with different set of arguments [duplicate]
Possible Duplicate:
How to create functions of arbitrary number of variables?
i want to use a Function f[] with different set of arguments.
example: ...
0
votes
1answer
113 views
Providing options to function [duplicate]
Possible Duplicate:
Functions with Options
I'm trying to write a Function With an option "Panel" which takes True or False as arguments.
Based on Panel Value (True/False), different ...
4
votes
2answers
156 views
How can I improve this trial division procedure?
My background is procedural programming, so I find this construction quite natural. Is there a way to get rid of the While?
...
