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Re: Modifying an array while conserving memory [message #30963 is a reply to message #30878]

Fri, 24 May 2002 08:38

Xiangyun Qiu
Messages: 6
Registered: November 2001

Junior Member

Randall Skelton wrote:
Hi there,

Provided TEMPORARY() function works as we expect, I think the following
steps can
use less memory:

a = findgen(1000)
b = randomu(seed,100)
a = shift(TEMPORARY(a), 500)
c = [TEMPORARY(b),TEMPORARY(a)]
c = Shift(TEMPORARY(c), 500) ; here happens to be 500 too, because
500 = 1000 - 500

This solely rely on TEMPORARY function, live or die with it.

Xiangyun

>
> Hi all,
>
> I have a large array and I would like to 'insert' some data into the
> middle of it. Imagine an array of 1000 points and having 100 points to
> insert beginning at index 500 (the resulting array will have 1100 points).
> Typically, I do not know the length of data I wish to insert until after
> 'a' is defined.
>
> a = findgen(1000)
> b = randomu(seed,100)
> c = fltarr(1100) ; seems wasteful to use more memory
> c[0:499] = a[0:499]
> c[500:599] = b
> c[600:1099] = a[500:999]
>
> In reality, 'a' is of order 2e7 so I would like to avoid making
> multiple copies of it. Does anyone have any suggestions regarding the
> most memory efficient way of doing this?
>
> Many thanks,
> Randall

--
Xiangyun

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[Message index]

		Modifying an array while conserving memory By: Randall Skelton on Thu, 23 May 2002 17:12
		Re: Modifying an array while conserving memory By: Xiangyun Qiu on Fri, 24 May 2002 10:06
		Re: Modifying an array while conserving memory By: Pavel A. Romashkin on Fri, 24 May 2002 09:11
		Re: Modifying an array while conserving memory By: Randall Skelton on Fri, 24 May 2002 08:43
		Re: Modifying an array while conserving memory By: Xiangyun Qiu on Fri, 24 May 2002 08:38
		Re: Modifying an array while conserving memory By: Randall Skelton on Fri, 24 May 2002 06:20

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