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Re: Counting list elements above/below a given value

• To: mathgroup at smc.vnet.net
• Subject: [mg17263] Re: Counting list elements above/below a given value
• From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
• Date: Fri, 30 Apr 1999 02:34:46 -0400
• Organization: Universitaet Leipzig
• References: <7g0qv1$drj@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Hi Bill,


Count[] need a Pattern[] as its second argument and

Count[Flatten[listname], a_ /; a<value]

will work as expected.

Hope that helps
  Jens

"W.W. Sampson" wrote:
> 
> I wish to count the number of elements within a list above
> a given value. I can do this using the following:
> 
> Length[Select[Flatten[listname], value > #1&]]
> 
> However, my list is a 280 x 280 matrix and consequently
> this takes a while to evaluate. My guess is that there
> must be something more efficient. I've tried:
> 
> Count[listname, value > #1&]
> 
> but the output given is 0, which I know to be incorrect.
> 
> Any ideas appreciated.
> 
> Bill