The form
(<"[EMAIL PROTECTED] { ])
is supported by special code and avoids the boxing.
Henry Rich
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] On Behalf Of Joey K Tuttle
> Sent: Thursday, January 03, 2008 2:37 PM
> To: Programming forum
> Subject: Re: [Jprogramming] selecting from matrix
>
> y =. 3 5 ; 3 7 ; 3 8 ; 5 2 ; 5 6
> >y
> 3 5
> 3 7
> 3 8
> 5 2
> 5 6
>
> NB. you can form the boxed y from yours with
>
> <"1 y
> y { i. 10 10
> 35 37 38 52 56
>
> NB. you would want something like
>
> 0 = y { tm
>
> At 21:28 +0200 2008/01/03, Kairit Sirts wrote:
> >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 records
> >pointing 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
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