Re: How to make large array

[Martin Schultz <martin.schultz(at)dkrz.de>]

renjie wrote:
> 
> I tried to make large array, however, in Windows,
> the largest I can made is 256MB, and in Unix is 1 GB,
> it's supposed that the limitation is 2GB, do you have any
> idea about the largest array in IDL?

Hmmmm. First of all, I don't think it is necessary to create arrays
larger than a couple of MBs in memory. And they get really clumsy and
slow: you must be extremely careful about when do you pass something
by reference or by value and when IDL will make a temporary copy of
the array. Think hard whether you can come up with a solution where
most of the data resides in a file and is only accessed piecewise. 

Second, I recall that Erik Korpela
(http://albert.ssl.berkeley.edu/~korpela/mmap/) wrote some stuff to
allow memory mapping of IDL arrays. From his web page it seems like
this would solve your problems in a very nice way.

Good luck,

Martin


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