Thanks, Devon. I see that you recognize the number 480189! And yes, I determined experimentally that the mapped file only needs the expected number of bytes so it doesn't really matter to me how much space is allocated for the array when it is in regular memory.
-Michael -----Original Message----- From: Devon McCormick [mailto:[EMAIL PROTECTED] Sent: Friday, January 05, 2007 1:16 PM To: Programming forum Subject: Re: [Jprogramming] How to interpret the space used by an arrayaccording to 7!:5 However, I believe your memory-mapped file needs only the actual allocation as you can calculate it. ... > > On 1/5/07, Michael Berry <[EMAIL PROTECTED] > wrote: > > > > The quick and helpful answers I get from this list encourage me to ask > > more > > questions. I hope that is OK. > > > > In my mental model of how things work, I imagine a J array to be stored > > as a > > fixed size header (or a header of size that is a function of the array > > rank) > > followed by the array contents. According to 7!:5, my floating point > > array > > seems to take up more space that that. This in on 32-bit Windows. > > > > > > $rater_sig02 > > 480189 19 > > 8**/$rater_sig02 > > 72988728 > > 7!:5 <'rater_sig02' > > 134217728 > > (7!:5 <'rater_sig02')%*/$rater_sig02 > > 14.7111 > > > > > > In addition to just intellectual curiosity, my practical question is > > whether > > I need to think about anything beyond the number of elements and the > > type of > > my array when creating a mapped file to contain it. > > > > -Michael > > > > =============== > > Michael J. A. Berry > > Data Miners, Inc. > > +1 617 742 4252 > > > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > > -- > Devon McCormick > ^me^ at acm. > org is my > preferred e-mail -- Devon McCormick ^me^ at acm. org is my preferred e-mail ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
