Thanks. I don't know why I thought it can't be that easy. > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:programming- > [EMAIL PROTECTED] On Behalf Of Roger Hui > Sent: Thursday, January 03, 2008 9:32 PM > To: Programming forum > Subject: Re: [Jprogramming] selecting from matrix > > m=: (10000 500 [EMAIL PROTECTED] 2) * 10000 500 [EMAIL PROTECTED] 0 > y=: _2]\ 3 5 3 7 3 8 5 2 5 6 > y > 3 5 > 3 7 > 3 8 > 5 2 > 5 6 > 0 = (<"1 y){m > 0 1 1 0 1 > > > > ----- Original Message ----- > From: Kairit Sirts <[EMAIL PROTECTED]> > Date: Thursday, January 3, 2008 11:29 > Subject: [Jprogramming] selecting from matrix > To: 'Programming forum' <[email protected]> > > > I have a 2 column matrix of indices: first column specifies the > > row index > > and the second specifies the column index. There may be several > > recordspointing to one row. For example: > > > > y > > 3 5 > > 3 7 > > 3 8 > > 5 2 > > 5 6 > > > > I have to check those specified locations in the target matrix > > to see if the > > values there are 0 or not. How should I do that? The target > > matrix shape is > > 10000 500, which probably sets some limits to possible operations. > > > > Kairit Sirts > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm
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