< i. 1: Improved

>> << Usr Pri JfC LJ Phr Dic Rel Voc !: Help Release

< i. 1: Improved

initial writing: 2002-02-13
last updated: 2004-10-26

The following dyads are now supported by special code for Boolean, integer, floating point, or literal vectors or scalars:

	`comp i. 0:`		`i.&0@:comp`
	`comp i. 1:`		`i.&1@:comp`
	`comp i: 0:`		`i:&0@:comp`
	`comp i: 1:`		`i:&1@:comp`
	`[: +/ comp`		`+/@:comp`

where comp is one of = ~: < <: >: > E. (< <: >: > not available for literal). Time and space savings depend on the arguments used. For example:

   ts=: 6!:2 , 7!:2@]    NB. time and space
   x=: ?1e6$1e9
   y=: 1.5e9

   ts '+/x<y'        
0.0339839 1.04973e6
   ts 'x +/@:< y'        NB. scan entire x
0.0205264 1280
   
   ts '(x<y) i. 1'
0.0295772 1.04941e6
   ts 'x (< i. 1:) y'    NB. immediate hit
4.1346e_5 1216
   
   ts '(x>:y) i. 1'
0.0393262 1.04954e6
   ts 'x (>: i. 1:) y'   NB. scan entire x
0.0218871 1216

   x1=: y 5e5}x
   ts '(x1>:y)i.1'
0.036011 1.04941e6
   ts 'x1 (>: i. 1:) y'  NB. scan half of x1
0.0109947 1216

>> << Usr Pri JfC LJ Phr Dic Rel Voc !: Help Release