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Re: array concatenation in 2-D [message #59622]

Fri, 04 April 2008 14:25

ben.bighair
Messages: 221
Registered: April 2007

Senior Member

On Apr 4, 3:31 pm, Jean H <jghas...@DELTHIS.ucalgary.ANDTHIS.ca>
wrote:
> elwood wrote:
>> I have a loop which calculates two variables x[i] and y[i]
>
>> At each iteration of the loop I calculate
>> x and y
>> And I'd like to concatenate x and y into a 2 column, unknown numbers
>> of rows
>> output array.
>> I'd like to dynamically grow the output array at each interation.
>
>> For example:
>> x=1 y=5 on first iteration
>> x=2, y=6 on 2nd iteration
>> I want an output array that looks like the below:
>
>> 1 5
>> 2 6
>
>> How do i achieve this without knowing the array size??
>
>> Tx!
>> -Elisha
>
> Elisha,
> You can concatenate the arrays, as you suggest:
>
> a = [[1,2],[3,4]]
> a = [[a],[5,6]]
> help,a
> ==>A INT = Array[2, 3]
>
> However, if you have many elements, this can be very resources
> consuming. Another option is to create a "big" 2*n array, to
> progressively fill it, to keep a counter on the number of entries, and
> finally to cut what you haven't used.... and similarly, if your array is
> not big enough, add a large number of rows and keep filling them (use
> the same concatenation method as above)
>

Hi,

As a second to the method jean suggests, you might want to consider
using Mike Galloy's collections objects which are efficient resizable
buckets for holding data. Check it out at ...

http://michaelgalloy.com/2006/04/24/collection-package-mgarr aylist.html

Cheers,
Ben

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[Message index]

		Re: array concatenation in 2-D By: ben.bighair on Fri, 04 April 2008 14:25
		Re: array concatenation in 2-D By: Jean H. on Fri, 04 April 2008 12:31
		Re: array concatenation in 2-D By: David Fanning on Fri, 04 April 2008 12:40
		Re: array concatenation in 2-D By: R.G. Stockwell on Fri, 04 April 2008 12:27
		Re: array concatenation in 2-D By: David Fanning on Fri, 04 April 2008 11:57
		Re: array concatenation in 2-D By: elwood on Tue, 08 April 2008 18:19

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