The difference seems negligible and it's hard to imagine a case where this
would be a bottleneck but the equivalence version is more straightforward
and simpler to read.
m1=. m2=. 1000 1000?@$2e9 NB. Integers
(100) 6!:2 'm1-:m2'
1.39989e_6
(100) 6!:2 '(<m1) = <m2'
2.08957e_6
m1=. (1+m1{~ix) (ix=. <?$m1)}m1 NB. One element difference
(100) 6!:2 'm1-:m2'
0.000489653
(100) 6!:2 '(<m1) = <m2'
0.000421613
m2=. (1+m2{~ix) (ix)}m2 NB. Change m2 to match
(100) 6!:2 'm1-:m2'
0.00116565
(100) 6!:2 '(<m1) = <m2'
0.00109277
m1=. m2=. 1000 1000?@$0 NB. Floating-point
(100) 6!:2 '(<m1) = <m2'
2.13473e_6
(100) 6!:2 'm1-:m2'
1.29315e_6
m1=. (1.00001*m1{~ix) (ix=. <?$m1)}m1
(100) 6!:2 '(<m1) = <m2'
0.000613599
(100) 6!:2 'm1-:m2'
0.00059765
m2=. m1=. <:+:1000 1000?@$0
m1-:m2 [ m1=. %.m1 [ m2=. %.m2
1
(100) 6!:2 '(<m1) = <m2'
0.00546757
(100) 6!:2 'm1-:m2'
0.00566366
m1-:m2 [ m2=. +:m2 [ m1=. 2*m1
1
(100) 6!:2 '(<m1) = <m2'
0.00527504
(100) 6!:2 'm1-:m2'
0.00525394
m1-:m2 [ m1=. %:m1 [ m2=. %:m2 NB. Complex
1
(100) 6!:2 'm1-:m2'
0.0163895
(100) 6!:2 '(<m1) = <m2'
0.0153239
m1=. (1+m1{~ix) (ix=. <?$m1)}m1
(100) 6!:2 'm1-:m2'
0.0153072
(100) 6!:2 '(<m1) = <m2'
0.0156345
On Mon, Nov 24, 2014 at 8:39 AM, Jon Hough <jgho...@outlook.com> wrote:
> This seems to work. Thanks.
> I'm assuming this must be faster than boxing...
>
> > Date: Mon, 24 Nov 2014 08:33:42 -0500
> > From: devon...@gmail.com
> > To: programm...@jsoftware.com
> > Subject: Re: [Jprogramming] Best way to check matrix equality
> >
> > m1 -: m2
> >
> > might be better.
> >
> > On Mon, Nov 24, 2014 at 8:30 AM, Jon Hough <jgho...@outlook.com> wrote:
> >
> > > What is the best (by which I mean fastest) way to test if two
> > > matrices/tables of the same shapeare element-wise equal?
> > > At the moment I always use < to box each matrix and then the equality
> test
> > > is simply to use =.But I am not sure if < is slow, or if there is a
> better
> > > way to do this.
> > > e.g. if m1 is some matrix and I have another matrix m2, which has the
> same
> > > shape, I do:
> > > (< m1) = (< m2)
> > > Is this the preferred way?
> > > Thanks,Jon
> > > ----------------------------------------------------------------------
> > > For information about J forums see http://www.jsoftware.com/forums.htm
> > >
> >
> >
> >
> > --
> > Devon McCormick, CFA
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
>
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>
--
Devon McCormick, CFA
----------------------------------------------------------------------
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