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Re: Insufficient capacity

• To: mathgroup at smc.vnet.net
• Subject: [mg86226] Re: Insufficient capacity
• From: David Bailey <dave at Remove_Thisdbailey.co.uk>
• Date: Thu, 6 Mar 2008 03:00:13 -0500 (EST)
• References: <fqlmme$jc0$1@smc.vnet.net>

Tugrul Temel wrote:
> Dear All,
> 
> I transfer large amount of data from Excel to Mathematica v.6 and try to
> do some matrix operations. The size of the matrces are (3500, 3500) with
> 10 digit numbers. However, Mathematica quits when I make the matrix
> operation.
> 
> How can I make it possible to do the matrix operations of large sizes? Is
> Grid Math an option in this respect? If so, I like to know how large data
> sets Grid Math can handle?
> 
> Thanks for the tips in advance.
> 
> Regards,
> Tugrul Temel
> 
> 
> 
> 
If the array is filled with real numbers it will occupy 98 MB of 
storage, so manipulating it should not be a problem. If however the 
array contains mixed integer and real numbers, it will not pack and will 
occupy 245 MB!

This may be part of your problem - use the ByteCount function on the 
array to determine its size. Of course, you don't specify what 
operations you are doing on your array.

If the array is help in variable arr (say) then you can clean it up with:

arr = Developer`ToPackedArray[N[arr]];

The fact that arrays are automatically packed where possible is only 
really visible when memory becomes tight or performance is an issue.

Grid Math lets you do a lot of operations in parallel - it will not help 
here, however if you post some code - perhaps with a link to a smaller 
version of your spreadsheet - someone will probably be able to help.

David Bailey
http://www.dbaileyconsultancy.co.uk