I suggest you avoid use of _. . Among other things, certain CPUs slows down by a large factor if your array contains it. (Sorry, don't have the URL right now that presents that benchmark.) If you want to use a datum to indicate missing values perhaps you can choose an "unlikely" value, such as _987987987e98 .
----- Original Message ----- From: "Philip A. Viton" <[EMAIL PROTECTED]> Date: Thursday, August 16, 2007 7:44 Subject: [Jprogramming] algebra of Indeterminate? To: [email protected] > > [typos hopefully corrected : sorry] > > Are there any rules for how Indeterminate (_.) combines with > other > arithmetic operations on numbers? (The Dictionary entry is > suprisingly spare). > > I see that (as I would have expected) > > 1 2 3 + 1 _. 3 is 2 > _. 6 > > and that <: 1 _. 3 is 0 _. 2 > > but on the other hand I was a bit surprised that > > 1 2 3 <. 1 _. 3 is > 1 2 3 > > > > Why? > > I was hoping to be able to use Indeterminate as a missing data > code > in some data I'm manipulating, hoping that subsequent data > transformations would respect it. If that seems to be a bad > idea, can > anyone suggest an alternative? ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
