- #1
observer1
- 82
- 11
In the calculus of variations, the integral itself is a "functional." It depends on the form of the function of the Lagrangian: q and q-dot
But I have seen this word "functional" used elsewhere in different contexts.
I have seen: "A functional is a real valued function on a vector space."
I have seen: "A function is a function of functions."
I understand how these are all used, but I am still bereft of a "precise" and "consistent" definition of this word.
Can someone provide it? (Perhaps the key is that there is no "consistent" definition?)
But I have seen this word "functional" used elsewhere in different contexts.
I have seen: "A functional is a real valued function on a vector space."
I have seen: "A function is a function of functions."
I understand how these are all used, but I am still bereft of a "precise" and "consistent" definition of this word.
Can someone provide it? (Perhaps the key is that there is no "consistent" definition?)