Page 1 of 1

[]NULL

Posted: Fri Jan 18, 2013 2:11 pm
by giangiquario
Version: 13.0.16306.1 32 Classic
Created: Jan 14 2013 at 19:36:46
Build ID: c169c6f1

When dealing with scalar []NULL, I noticed that:

Code: Select all


]cpu '200 200⍴⎕null'

* Benchmarking "200 200⍴⎕null"
             Exp
 CPU (avg):    0
 Elapsed:      0

      ]cpu '200 200↑⎕null'

* Benchmarking "200 200↑⎕null"
               Exp
 CPU (avg):  15179
 Elapsed:    15179


Re: []NULL

Posted: Fri Jan 18, 2013 2:39 pm
by JohnS|Dyalog
Hi Gianluigi,
The overtake is creating new instances of the structure we use to represent ⎕NULL, whereas the reshape is just duplicating a pointer. I have logged an RFE (request for enhancement) ref [9126] to address this performance issue.
Thanks for taking the time to report it.
John.