Good one.


----- Original Message -----
From: Don Guinn <[EMAIL PROTECTED]>
Date: Thursday, June 12, 2008 4:42
Subject: Re: [Jprogramming] find row and column indices
To: Programming forum <[email protected]>

> How about?
>    4$.$.tst
> 0 3
> 2 0
> 3 3
> 5 0
> 
> On Wed, Jun 11, 2008 at 6:34 PM, Sherlock, Ric 
> <[EMAIL PROTECTED]>wrote:
> 
> > Thanks Roger & Henry,
> > They are much simpler than the other way I just realised I had 
> already> created in the other thread.
> >
> > ind0=: (1 , {:@$) *"1 [: (<. ,. 1&|) {:@$ %~ [: I. ,  
> NB. RS
> > ind1=: [:;(i.@:# ,.&.> <@I.)  NB. RS
> > ind2=: $ #: I.@,   NB. RH & HR
> > ind3=: , # (#: i.@(*/))@$  NB. HR
> >
> > Interestingly ind0 is actually very competitive with ind2, but 
> would need
> > more work to sort out tolerance (and is specific to matrices).
> >   tmp=: 0.0000001>1e6 [EMAIL PROTECTED]
> >   +/+/tmp
> > 9
> >   ts=: 6!:2 , 7!:[EMAIL PROTECTED]
> >
> >   ts 'ind0 tmp'
> > 0.264977043172 134218688
> >   ts 'ind1 tmp'
> > 3.26141171573 221066560
> >   ts 'ind2 tmp'
> > 0.2667722434 134218688
> >   ts 'ind3 tmp'
> > |out of memory: ind3
> > |       ind3 tmp
> >
> > ---Roger Hui wrote:
> > > ($tst) #: I. , tst
> > >
> > > Works for any rank array, not just matrices.
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm

Reply via email to