comp.lang.idl-pvwave archive: archive » Re: Unpacking algorithm

Home » Public Forums » archive » Re: Unpacking algorithm

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

Re: Unpacking algorithm [message #39322 is a reply to message #39317]

Sun, 16 May 2004 21:37

MKatz843
Messages: 98
Registered: March 2002

Member

You could also use where() to find the indices of the "zero" elements,
or their complement, that is the indices of the non-zero elements.

v0=[0 x1 x2 x3 0 x4 x5 x1 0 x2 x3 x4 0 x5 x1 x2 0 x3 x4 x5]
w2 = where(v0 NE 0, complement=w1) ;--- returns an array of indices
v2 = v0(w2)
v1 = v0(w1)

There are also very handy keywords: count and ncomplement that return
the number of indices of each kind that are found. Note that where()
returns -1 when there are no matches. If you try to use v0(w1) and w1
is -1 you'll get an error. That's where the count variables come in. I
usually do something like "if count GT 0 then (do something)" to avoid
the error.

M. Katz

"Tmorri" <torrimorri@yahoo.com> wrote in message news:<52e0072063f360e0705e8ac96f274e52@localhost.talkaboutprogramming.com>...
> one second thought,
>
> Does any one have an algorithm to unpack this vector
>
>
> v0=[0 x1 x2 x3 0 x4 x5 x1 0 x2 x3 x4 0 x5 x1 x2 0 x3 x4 x5]
>
> in the following way:
>
> v1=[0 0 0 0 0]
>
> v2=[x1 x2 x3 x4 x5 x1 x2 x3 x4 x5 x1 x2 x3 x4 x5]
>
> x1,x2,x3,x4,x5 are variables that can take any value, even zero, (0).
>
> I just want to get rid othe zeroes (every fourth element)shown in vector
> v0
>
>
> Thanks,
>
> Tmorri

Report message to a moderator

[Message index]

		Re: Unpacking algorithm By: Timm Weitkamp on Mon, 17 May 2004 06:41
		Re: Unpacking algorithm By: MKatz843 on Sun, 16 May 2004 21:37
		Re: Unpacking algorithm By: Christopher Lee on Sun, 16 May 2004 08:19
		Re: Unpacking algorithm By: Tmorri on Sat, 15 May 2004 16:00

Previous Topic:	Re: allocate heap? yes or no?
Next Topic:	Re: Unpacking algoritmn

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Fri Oct 10 10:19:42 PDT 2025

Total time taken to generate the page: 1.39417 seconds