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Re: Find Max of "Concave" List

• To: mathgroup at smc.vnet.net
• Subject: [mg12975] Re: [mg12918] Find Max of "Concave" List
• From: Sean Ross <seanross at worldnet.att.net>
• Date: Sun, 28 Jun 1998 02:52:00 -0400
• References: <199806240744.DAA03105@smc.vnet.net.>
• Sender: owner-wri-mathgroup at wolfram.com

Chris Farr wrote:
> 
> I have a one-dimensional list which is concave.  That is, if you did a
> ListPlot on the list you would have a concave curve.
> 
> Given the concavity, when finding the max, it is inefficient to use
> Max[] which does a comparison on all elements of the list.
> 
> Is there an elegant way to exploit the concavity when performing a
> Max[]?  That is, the algorithm should stop when the next element in the
>  list is lower then the previous element.  This would limit the number
> of  comparisons.
> 
> Thanks,
> 
> Chris Farr

You can use Return, Catch, Throw and Break to control the flow of
programs.  If you had a loop of some kind, you could Break whenever the
condition was met or you could wrap your loop in a Catch and Throw
whenever a condition was met.  You could also just use a while loop and
put the "abort early" criteria into the While loop.

• References:
  • Find Max of "Concave" List
    • From: "Chris Farr" <farr@brown.edu>