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.
2
votes
0answers
70 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.
...
2
votes
0answers
76 views
Evaluating a function on permutations of its arguments
Say I have a function "temp" of $n+1$ variables, $y,z1,z2,z3,...,zn$. I want to test if my function has certain symmetries like swapping $y$ with square of any $z$, swapping any two of the zs, ...
2
votes
1answer
98 views
Difference between function definitions [duplicate]
Possible Duplicate:
Functions vs. patterns
I thought about describing the context in which I faced this problem, but I figured it is general enough and clear enough to pose it as it is.
...
2
votes
0answers
194 views
Generating a function which outputs possible chemical reactions
I want to make a list of chemical reactions and I write them down in a $\require{mhchem}\LaTeX$ format. They are of the following form
$$NA_n^i+MB_m^j \rightarrow \hat NA_{\hat n}^{\hat i}+\hat ...
1
vote
2answers
135 views
Write a function that returns the logarithmic derivative
How can we write a function that if we input an expression f, it returns the log derivative $\frac{1}{f} \frac{df}{dx}$. We have to use a conditional or pattern test so that the function accepts any ...
1
vote
2answers
396 views
How to define a differential operator?
I have a linear differential operator, for instance, $L\left (\partial _{t} \right )=\partial _{tt} - 3\partial _{t} + 2$. I use it in 2 different ways:
apply the operator to a function: $L\left ...
1
vote
3answers
142 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 :
...
1
vote
1answer
245 views
Matrix Multiplication Modulo 2
I would like to perform matrix multiplication modulo 2. Hence, instead of the usual:
A.B
I did:
...
1
vote
1answer
634 views
“Tag times protected” for this doesn't make sense
I have a property calculator which is in a Table to generate well... a table of properties and growth rates depending on the value of ...
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?
...
1
vote
2answers
127 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: ...
1
vote
1answer
73 views
Why function is evaluated backward?
I have a simple function:
f[x0_,y0_]:= Module[{x=x0,y=y0},For[i=0,i<2,i++;Print[x],Print[x+y]];]
So when I call it:
...
1
vote
3answers
157 views
Variables Inside Functions Not Evaluating
x = 5*y
function1[y_] := x
function1[5]
Am I wrong in thinking that function1[5] should equal 25? Instead this comes out.
...
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 ...
1
vote
3answers
250 views
Generating pairs of additive and multiplicative factors for integers
Given an integer $n$, I want two lists:
a) the set of pairs of the divsors $a,b$ into exactly two factors $n=a\cdot b$,
b) the set of pairs $a,b$ of two summands $n=a+b$.
The code I came up ...
1
vote
2answers
104 views
How to mix Unevaluated property of function arguments with expression assignments?
This is a follow-up to my (solved) question How to distribute a generic function of two arguments (without evaluating the arguments)
Say, I have a binary function
...
1
vote
2answers
187 views
Using Functions as Arguments to Function
I am trying to make a function like Norm but defined like so: MyNorm[{x_,y_,z_}]=Sqrt[x^2+y^2+z^2]. Mathematica assumes that x, ...
1
vote
1answer
55 views
NMaxmize with a list of variables
I want to use NMaximize to find the maximum value of a function with multiple variables. The problem is I would like to set this up so the number of variables is only decided when the function sees ...
1
vote
1answer
102 views
Function definition and delayed assignment
I need to define the following function
MyWavelet[n_]["PrimalLowpass", prec_ : MachinePrecision] :=
Table[(-1)^(j - 1) h[[2*n - j]], {j, 0, 2*n - 1}]
which ...
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 ...
1
vote
1answer
131 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 ...
1
vote
1answer
149 views
Why does the first derivative of a piecewise continuous function turns out with discontinuities?
I have this piecewise continuous function which is also continuously differentiable over time :
...
1
vote
2answers
95 views
A function that only evaluates on lists of pairs [duplicate]
Possible Duplicate:
Why doesn’t PatternTest work with Composition?
I'd like my function to only evaluate when the argument is a list of pairs. It seems like ...
1
vote
1answer
111 views
Find the derivatives of arbitrary order of a function found using NDSolve
For the following initial value problem
BC[b_]:=x[0]==b;
eq[b_]:=NDSolve[{equation==0, BC[b]}, x, {t,0,1000}];
body[t_,b_]:= x[t]/.eq[b];
one could define the ...
1
vote
2answers
182 views
Piecewise function with a function as argument
I want to define a piecewise function, which has two arguments, one of which is a function of the other's piecewise argument. I am giving an example
...
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 ...
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 ...
1
vote
2answers
101 views
How can define a set of nested parameters
I would like to know how I to define a function with a nested set of parameters (or whatever you would like to call it). For example, how would I get the following function ...
1
vote
1answer
166 views
1
vote
1answer
77 views
Mathematica plots a discontinuity in piecewise function that does not exist [duplicate]
I have the following function defined:
...
1
vote
0answers
73 views
How can I obtain the function described by given set of central moments?
I want to investigate how my function P behaves with different probability functions rho as input variables.
This means
...
1
vote
0answers
97 views
Return Functions from parallel execution of module
I wrote a module which numerically solves an ODE using NDSolve. The result from this is e.g. either ...
1
vote
0answers
76 views
Non Commutative Multiply [duplicate]
Possible Duplicate:
Non-commutative symbolic linear algebra
I want to multiply two matrices, for example,
A = {{e, f}, {g, h}}
B = {{a, b}, {c, d}}
...
0
votes
2answers
147 views
Why function cannot be defined inside For loop? [closed]
I have a following code (which is simplified version of what I am doing):
For[i = 1, i <= 5, i++,
f[x_] := Sin[x]^2
Print[{i, f[i]}]
]
And the question ...
0
votes
3answers
138 views
Better solution than returning a list of 3 values?
I have a function (using SetDelayed) that currently returns 3 values in a list. Later on I use the result of this list along with ...
0
votes
1answer
260 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 ...
0
votes
1answer
160 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 ...
0
votes
2answers
130 views
Constraining two points, a specified distance apart, to a line
Suppose that I have two points in the xy plane: pt1 and pt2init. pt1 is fixed in space, ...
0
votes
1answer
112 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 ...
0
votes
1answer
65 views
Function giving negative value when it should be positive [closed]
I am trying to evaluate
$$\displaystyle J=A\sum_{k=0}^{n-2}(-1)^k{n-2 \choose k}B^{n-2-k}\left(\frac{C_1}{k+n}-\frac{C_2}{k+n+1}+\frac{C_3}{k+n+2}-\frac{2}{k+n+3}\right)$$
in Mathematica as a function ...
0
votes
1answer
75 views
Given a sequence of expressions, how can I convert them all into functions?
I have a sequence of expressions
1, x, x^2, ..., x^5
I want to define a sequence of functions out of it, what should I do? Namely I want to define a vector of ...
0
votes
1answer
191 views
How can I define a Step-Wise function in Mathematica (Not using Heaviside Step Function)? [closed]
I need to define a function, which has very different behaviour in different regions. There are about 13 different regions. A sample of my function is the foloowing table:
I want to define it as a ...
0
votes
1answer
133 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
...
0
votes
1answer
102 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 ...
0
votes
2answers
129 views
Fast Autocorrelation Computation
I want to compute the Autocorrelation Function (ACF) of a data table with $10^6$ entries. I know that there is a built-in function in Mathematica for that, but because I do not know how exactly it is ...
0
votes
1answer
127 views
0
votes
1answer
77 views
How could we define a function recursively?
Let us first consider the constructon of the following simple iteration
...
0
votes
2answers
83 views
How to use Solve rules as a function body?
Solve gives me an expression which I want to use as the body of a function. Rather than run Solve every time inside my function ...
0
votes
1answer
67 views
Defining functions from expressions of variable lengths
I have a list of symbols that I have defined using
d = Table[Symbol["d" <> ToString[i]], {i, 1, n}]
giving
...
0
votes
0answers
9 views
How to assign values to a function at discrete points? [duplicate]
Suppose we are interested in a function f[x] that is defined only at discrete points:
x = {1.1, 2.1, 3.1, 4.1, 5.1}
We want to ...
