| Boxed Array References Improved |
initial writing: 2005-07-22 last updated: 2006-02-02 |
Previously, referencing a boxed array x took time proportional to the number of subarrays in x . J 6.01 fixes this performance bug so that referencing a boxed array takes constant time. The following benchmarks demonstrate the improvement:
x=: 1e6 $ <123 y=: 10 $ < 1e5 $ <123 ts=: 6!:2 , 7!:2@] NB. time and space ts 'Expression'
| Expression | J 6.01 | J 5.04 | Ratio | |||||||||
| #x | 2.30611e_6 | 640 | 0.0318275 | 640 | 13801 | 1.00 | ||||||
| #y | 2.22213e_6 | 640 | 0.0311371 | 640 | 14012 | 1.00 | ||||||