The operators tag has no wiki summary.
-3
votes
0answers
53 views
How to define operator for variation of the function [closed]
I am thinking how to use rule for variation of functions. I need to define [Delta] as a operator to change input to the output form automatically using variational principle. But Mathematica doesn't ...
8
votes
3answers
204 views
Replace operators
/. can be used to replace variables but how can one replace operators.
For example in a * b, ...
1
vote
0answers
40 views
Definition of differential operators [duplicate]
I am curious how differential operators are defined in Mathematica. More specifically, if the Laplacian function wasn't available, how would one go on to define such a function in Mathematica directly ...
0
votes
0answers
60 views
How to define the tangent gradient operator? [duplicate]
I would like to define a new differential operator that is the tangent gradient for a curve $\Sigma$.
This is defined as $$\nabla_\Sigma=\mathbf{P}\nabla$$ where $\mathbf{P}$ is the projection ...
0
votes
0answers
79 views
Efficient way to give symbolic elements symmetry
I have a symbolic expression that represents a set of operators. These operators have quite a bit of symmetry to simplify expressions:
...
1
vote
2answers
134 views
Replacing values of a function
I have recently starting using Mathematica and have recently come to what seems as an impasse in my understanding of the language. If this is too "tell me how to do it" I would certainly understand.
...
3
votes
2answers
171 views
why I can't define a commutator operator in this way？
I am trying to define some operators I used frequently.For example, I defined a KroneckerProduct operator as $ \otimes $ as follows:
a_$ \otimes $b_:=a.b-b.a
and this works fine.
Then I want to ...
3
votes
2answers
185 views
7
votes
1answer
231 views
How do I expand a sum?
I have a problem with Mathematica's symbolic manipulations. As an example, consider the following expression:
$$\sum _{i=1}^n -2 x_i \left(-a x_i-b+y_i\right)=0$$
How do I get Mathematica to expand ...
4
votes
1answer
239 views
How to change coordinates of a differential operator?
I'm doing a basic quantum mechanics problem and am trying to learn how to do it in Mathematica. Any help would be much appreciated.
$\vec{L} = \vec{x} \times \vec{p}$
where $\vec{x}$ has ...
8
votes
2answers
176 views
Change associativity of the @ operator
The @ operator in Mathematica is right-associative by default, i.e.
f@g@h
evaluates as
f@(g@h)
Is it possible to make the ...
4
votes
2answers
841 views
How to find (numerical) value of a derivative at point?
I have the following function:
f[0, 0] = 0
f[x_, y_] := Exp[-(x^2 + y^2)^(-1)]
How do I find its partial derivatives at any given point, including $(0,0)$? This ...
18
votes
11answers
626 views
Generating an ordered list of pairs of elements from ordered lists
I have a pair of ordered lists. I want to generate a new ordered list (using the same ordering) of length n by applying a binary operator to pairs of elements, one from each list, along with the index ...
5
votes
3answers
245 views
ComplexInfinity/Indeterminate error when evaluating derivative
Motivation: I want to find the coefficients for the polynomial that is obtained when one adds together the first $n$ natural numbers to the power of $a$; that is, when you consider $1^{a} + 2^{a} + ...
6
votes
3answers
434 views
Using D to find a symbolic derivative
I need to do the following:
Define a function
Take the derivative of this function and have a look at the symoblic representation
Substitute in some values
With the bonus that I want to use the ...
