comp.lang.idl-pvwave archive: archive

Home » Public Forums » archive » x*x versus x^2

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

x*x versus x^2 [message #61206]

Wed, 09 July 2008 09:32

Conor
Messages: 138
Registered: February 2007

Senior Member

So I've been looking at execution time for various algorithms, and I
found this interesting result:

bigarr = fltarr(1000,1000)

t1 = systime(/seconds)
t = bigarr^2.0
t2 = systime(/seconds)
t = bigarr*bigarr
t3 = systime(/seconds)

print,t2-t1
print,t3-t2

IDL prints:

0.024163008
0.010262012

Apparently multiplying an array by itself is twice as fast as using
the carat operator! Anyone know why this is? Is it a memory issue or
something?

Report message to a moderator

[Message index]

		x*x versus x^2 By: Conor on Wed, 09 July 2008 09:32
		Re: x*x versus x^2 By: Sven Geier on Sat, 12 July 2008 12:30

Previous Topic:	Re: IDL Adventure!?
Next Topic:	number problem

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Fri Nov 28 18:36:10 PST 2025

Total time taken to generate the page: 0.24279 seconds