comp.lang.idl-pvwave archive: archive » matrix multiplication

Home » Public Forums » archive » matrix multiplication

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

Re: matrix multiplication [message #63168 is a reply to message #63073]

Tue, 28 October 2008 14:32

russ[1]
Messages: 8
Registered: April 2008

Junior Member

On 28 Oct, 20:59, Chris <beaum...@ifa.hawaii.edu> wrote:
> On Oct 28, 8:42 am, David Fanning <n...@dfanning.com> wrote:
>
>
>
>> russ writes:
>>> Probably a stupid question but I haven't used idl for a while
>
>>> Is there a quicker way of doing this?
>
>>> a=fltarr(1000,20)
>>> b=fltarr(20)
>
>>> for i=0,999 do begin
>>> a(i,*)=a(i,*)*b
>>> endfor
>
>> It might be faster to realize the end result is going
>> to be an array of zeros than it would be to actually
>> write the code. :-)
>
>> But, I think you want this:
>
>> a = a * rebin(reform(b, 1, 20) ,1000, 20)
>
>> Cheers,
>
>> David
>> --
>> David Fanning, Ph.D.
>> Coyote's Guide to IDL Programming (www.dfanning.com)
>> Sepore ma de ni thui. ("Perhaps thou speakest truth.")
>
> I also like this shortcut for reform:
> a = a * rebin(1#b, 1000, 20)
>
> chris

many thanks to you both

Russ

Report message to a moderator

[Message index]

		matrix multiplication By: c1dje on Mon, 22 March 1993 14:51
		Re: Matrix multiplication By: Haje Korth on Fri, 14 November 2003 09:48
		Re: matrix multiplication By: Chris[6] on Tue, 28 October 2008 13:59
		Re: matrix multiplication By: russ[1] on Tue, 28 October 2008 14:32
		Re: matrix multiplication By: David Fanning on Tue, 28 October 2008 11:42
		Re: matrix multiplication By: Vince Hradil on Tue, 28 October 2008 19:17

Previous Topic:	Re: DLM unload
Next Topic:	DLM unload

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Sun Oct 12 07:01:30 PDT 2025

Total time taken to generate the page: 2.63937 seconds