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*Subject*: Zero vector detection in IDL*From*: Frank Morgan <frank.morgan(at)jhuapl.edu>*Date*: Mon, 28 Jun 1999 16:51:31 -0700*Newsgroups*: comp.lang.idl-pvwave*Organization*: Johns Hopkins University Applied Physics Lab, Laurel, MD, USA*Xref*: news.doit.wisc.edu comp.lang.idl-pvwave:15421

Given a big byte or integer array (actually a 1-D vector), is there a fast IDL way to check whether any non-zero elements exist? Something like "if (total(x) EQ 0)..." or a where() construct will work, but scans the whole vector when the first non-zero element is enough to answer the question. max(x) is even worse. On the other hand: for i=0,n-1 do begin if (x(i) NE 0) then begin (it's not all zero) goto, BREAK endif endif BREAK: will stop early if possible, but looping a conditional is maybe not the fastest structure in IDL. An internal command that implements the loop concept would be what I'm looking for I think but I don't know if it exists. Any better ideas? Thanks, Frank frank.morgan@jhuapl.edu

**Follow-Ups**:**Re: Zero vector detection in IDL***From:*J.D. Smith

**Re: Zero... THANKS Pavel and J.D.***From:*Frank Morgan

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