The monad <./ .+~^:_ is equivalent to the monad
<./ .+^:_~ but can be substantially faster and
leaner. For example:
(<./ .+^:_~ -: <./ .+~^:_) a=: 200 200 [EMAIL PROTECTED] 100
1
ts=: 6!:2 , 7!:[EMAIL PROTECTED]
ts '<./ .+^:_~ a'
0.506575 3.41446e6
ts '<./ .+~^:_ a'
0.173773 2.10323e6
$ <./ .+^:a:~ a
15 200 200
$ <./ .+~^:a: a
5 200 200
----- Original Message -----
From: eesuk <[EMAIL PROTECTED]>
Date: Friday, January 19, 2007 5:08 pm
Subject: Re: [Jprogramming] length of the path between two nodes in a tree
> NB. x : (# of nodes);r
> NB. y : travel pairs
> NB. a : adjacency matrix
> NB. d : all pair distance matrix
>
> length2=: 4 : 0
> 'N r'=.x
> a=.(<.|:)1 (;/r)}_ 0{~ =i.N
> d=.((<./ . +)^:_)~ a
> d{~;/y
> )
>
> r=:0 2, 0 1, 2 3, 2 5, 2 7, 5 6,: 1 4
>
> (8;r) length2 7 6,4 7,4 6,:0 6
> 3 4 5 3
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