I’d expect it’s allocation and copying. And as you execute it in the repl, there’s no compiler involved. Rather, the JE “knows” it’s dealing with a single element only.
Am 25.10.20 um 11:52 schrieb pietdion: > Ok. Thanks. > What explains the huge time difference? > Does the compiler somehow “know” it’s only dealing with one element in the in > place assignment? > >> On 25 Oct 2020, at 7:25 pm, Lippu Esa <[email protected]> wrote: >> >> Hello >> >> It is not expensive if an in place assignment can be made: >> >> a=.i.1e7 >> ts '(_999+1000{a) 1000 }a' >> 0.07655064 134219392 >> ts 'a=.(_999+1000{a) 1000 }a' >> 0.00000177 1792 >> >> Esa >> >> -----Original Message----- >> From: Programming <[email protected]> On Behalf Of >> pietdion >> Sent: Sunday, October 25, 2020 9:58 AM >> To: Programming forum <[email protected]> >> Subject: [Jprogramming] Adding constant to a specified element of a vector >> >> What is the best way to add, say, scalar x to component i of vector y? >> >> One way is (x + i{y) i} y >> But this seems clumsy/expensive. >> Is there a cleaner/more efficient way? >> ---------------------------------------------------------------------- >> For information about J forums see >> https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.jsoftware.com%2Fforums.htm&data=04%7C01%7C%7C846dab3174224b01be8508d878bbba64%7C5090e269dbea4e98a9aa3e70be5890f7%7C0%7C0%7C637392094979944278%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=q2LAzVmaMgPTY86v0%2FpBEascSJSwOoSYOMbgwC%2FxQUQ%3D&reserved=0 >> >> Tämän viestin sisältö liitteineen on luottamuksellinen ja tarkoitettu vain >> sen vastaanottajalle. Jos et ole viestin tarkoitettu vastaanottaja, pyydämme >> sinua poistamaan viestin liitteineen ja sen jälkeen ilmoittamaan asiasta >> välittömästi viestin lähettäjälle. Viestin sisällön paljastaminen, >> kopioiminen tai muu käyttö on kielletty. >> >> The contents of this message and any attachments are confidential and meant >> solely for the intended recipient. If you are not the intended recipient, we >> kindly ask that you delete the message and its attachments, and immediately >> notify the sender of the email. Disclosing, copying or using the contents of >> the message is strictly prohibited. >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- ---------------------- mail written using NEO neo-layout.org ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
