RPL mini-challenge: Create an anti-Identity Matrix

[Claudio L.]

I did some timings with newRPL on real 50g hardware. All times are for 1000 executions with argument of 30:

Code:


«
  IDN NEG DUP 1 CON + 
»

Total time: 12.411 seconds
Bytes: 32

Code:


«
  1 - → 
    N « 0 N FOR 'K' 1 N NDUPN 1 + K - 0 SWAP ROLLD 
    NEXT
    N 1 + DUP 2 →LIST →ARRY 
  »
»

Total time: 2.336 sec
Bytes: 132

Code:


«
  IDN AXL NOT AXL 
»

Total time: 96.751 sec
Bytes: 24

Code:


«
  → 
    N « 1 N FOR 'I' 1 N FOR 'J' I J ≠ 
      NEXT
    NEXT
    N N 2 →LIST →ARRY 
  »
»

Total time: 11.969 sec
Bytes: 112

And finally, I think the fastest implementation is Pier idea with 3298 improvements:

Code:


«
  2 OVER START
    0 1 ROT NDUPN 
  NEXT
  0 SWAP DUP 2 →LIST →ARRY 
»

Total time: 1.946 sec
Bytes: 64

Clearly, the advantage is in the element-by-element approach (EDIT: versus the full matrix ones, and "packed" elements using NDUPN is the winner approach).

EDIT: Added total bytes of each version in newRPL (for completeness only).