[Date Index]
[Thread Index]
[Author Index]
the Operate[] function
*To*: mathgroup at smc.vnet.net
*Subject*: [mg109972] the Operate[] function
*From*: AK <aaarbk at googlemail.com>
*Date*: Thu, 27 May 2010 06:43:09 -0400 (EDT)
Dear all,
Can anyone tell me what the Operate function is good for?
Looking at the help, it says Operate[p, f[x,y]] gives p[f][x,y].
Concentrating on just the rhs above for a moment, the only obvious way
to me of attaching a useful meaning to it is that if p is a function
that takes another function f, and additionally has some anonymous
parameters - I mean #1,#2, etc.; sorry if i've got the terminology
wrong - say for example:
p[f_] = f[#1] + #2^2 &
then p[Sin][4,3] has some meaning
Coming back to Operate's definition, the corresponding lhs wrt is
Operate[p, Sin[4,3]]
which looks problematic first of all because Sin[] is being passed two
parameters instead of one. (Mathematica complains if you run the
above command, but still gives the answer expected from Operate's
definition)
So unless f happens to take the same number of arguments as the #
arguments in p, the usage seems rather awkward in the first place...
or does its intended application lie precisely in cases where both p
and f have the same number of parameters, or where f can take a
variable number of parameters (I haven't looked at Mathematica
functions with variable number of parameters yet, so I'm just
guessing). Or did I miss the point entirely?
Regards,
AK
Prev by Date:
**"Simplifying" expressions to not expand user-defined functions**
Next by Date:
**Re: Trouble with Unevaluated**
Previous by thread:
**"Simplifying" expressions to not expand user-defined functions**
Next by thread:
**MathLink in Vista**
| |