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Re: Help [message #15543 is a reply to message #5724]

Fri, 21 May 1999 00:00

Martin Schultz
Messages: 515
Registered: August 1997

Senior Member

Tri VU KHAC wrote:
>
> Hi folks,
>
> I'm looking for an efficient way to produce the matrix of type (I woulk
> like to be able to avoid the FOR statement)
>
> 0 1 0 1 0 1 0 1
> 1 0 1 0 1 0 1 0
> 0 1 0 1 0 1 0 1
> 1 0 1 0 1 0 1 0
>
> OR
>
> 1 0 0 1 0 0 1
> 0 1 0 0 1 0 0
> 0 0 1 0 0 1 0
> 1 0 0 1 0 0 1
>
> ETC.
>
> Best regards,
> Tri.

Isn't that coincidence? Take a look at the recent discussion on "AN
array slicing function". I posted a routine ARREX that will do the
opposite of what you are looking for, i.e. you could extract all the 1's
from your matrix with it (probably need several calls though). Now you
can go ahead and use the function arrex_ComputeInd (included in
arrex.pro) to come up with a function arrexi that returns the indices
rather than the values, and then you would write

A = intarr(8,4)
A[arrexi(A,[1,0],-1,[2,2]) = 1
A[arrexi(A,[0,1],-1,[2,2]) = 1

(or similar) ... If you wait a little, I'll hack arrexi for you as soon
as soem other folks have confirmed that arrex works.

Regards,
Martin.

--

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Martin Schultz, DEAS, Harvard University, 29 Oxford St., Pierce 109,
Cambridge, MA 02138 phone (617) 496 8318 fax (617) 495 4551
e-mail mgs@io.harvard.edu web http://www-as/people/staff/mgs/

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[Message index]

		Help By: psumartoira on Fri, 02 February 1996 00:00
		Re: Help By: Vapuser on Wed, 26 May 1999 00:00
		Re: Help By: R.Bauer on Tue, 25 May 1999 00:00
		Re: Help By: Pavel Romashkin on Fri, 21 May 1999 00:00
		Re: Help By: Martin Schultz on Fri, 21 May 1999 00:00
		Reading ASCII files as structure: Help By: limiqt on Wed, 30 September 2015 19:15
		Re: Reading ASCII files as structure: Help By: penteado on Thu, 01 October 2015 19:25

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