Old and senile as I am, this looks to me like a problem in calculus of
variations.See, e.g., en. wikipedia.org/wiki/Calculus_of_variations. You
are not likely to get the solution by guessing that the shape is
elliptical, or catenary, or parabolic, etc. I am too old and lazy to try
to solve it myself. I would like to see someof you who are smarter and
more energetic than I give it a go. I feel reasonably certain that the
problem has a closed form solution and that writing that out in J would
not be difficult. What would be reallyimpressive would be a numerical
method of doing calculus of variations, in J, of course.
On 2/23/2013 4:28 PM, Ric Sherlock wrote:
Kip,
Alternative formulations for your adverb that require fewer calculations of
u y.
Max1 =: 1 : 0
((= >./)@:u # ] ,. u) y
)
Max2 =: 1 : 0
fnres=. u y
where=. (= >./) fnres
where # y ,. fnres
)
I'd be interested in a tacit implementation of one of the adverbs Max
above. I came up with the same as Pepe for a simple Max ( >./@: ) but
can't see how to "factor out" the verb area from the adverbs in the
following:
Max3=: (({~ area ((i. >./)@:)) , area (>./@:))
On Sun, Feb 24, 2013 at 9:18 AM, km <k...@math.uh.edu> wrote:
Borrowing ideas from Raul, I like
Max =: 1 : 0
max =. >./ u y
where =. max = u y
where # y ,. u y
)
which identifies the max and where it occurs:
*: Max i:2
_2 4
2 4
(4 - *:) Max i:2
0 4
Sent from my iPad
On Feb 23, 2013, at 1:04 PM, Jose Mario Quintana <
jose.mario.quint...@gmail.com> wrote:
I did not see your second post!
area=. ] * 50 - %&2
area(max=. (>./) @:) 0 to 100
1250
max
./@:
On Sat, Feb 23, 2013 at 1:46 PM, km <k...@math.uh.edu> wrote:
Can we have an adverb Max so that f Max y finds the maximum of f on
the list y ?
Sent from my iPad
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