Re: Counting nonzeros
- To: mathgroup at smc.vnet.net
- Subject: [mg86887] Re: Counting nonzeros
- From: Bill Rowe <readnews at sbcglobal.net>
- Date: Tue, 25 Mar 2008 01:16:23 -0500 (EST)
On 3/24/08 at 1:44 AM, carlos at Colorado.EDU wrote: >I want to count the # of NZ entries in an arbitrary multilevel list, >say exp, that contains only integers. Is this the easiest way: >k = Length[Flatten[exp]]-Count[Flatten[exp],0] There are a number of ways to do what you want. I think using Unitize to convert the non-zero entries to 1 and then summing using Total is likely to be the fastest, i.e., Total[Flatten@Unitize@exp] or Total[Total@Unitize@exp]