Re: Counting list elements above/below a given value
- To: mathgroup at smc.vnet.net
- Subject: [mg17244] Re: Counting list elements above/below a given value
- From: "Stephen P Luttrell" <luttrell at signal.dra.hmg.gb>
- Date: Fri, 30 Apr 1999 02:34:36 -0400
- Organization: Defence Evaluation and Research Agency
- References: <7g0qv1$drj@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
W.W. Sampson wrote in message <7g0qv1$drj at smc.vnet.net>... >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. Try this Count[listname, _?(#>0&)] Stephen P Luttrell Signal Processing and Imagery Department DERA Malvern, St.Andrew's Road Malvern, United Kingdom, WR14 3PS +44 (0)1684 894046 (tel) +44 (0)1684 894384 (fax) luttrell at signal.dera.gov.uk (email)