[Beowulf] array shape difference

Michael H. Frese Michael.Frese at NumerEx-LLC.com
Thu Nov 12 04:18:41 PST 2009


That's correct.  The executable size would reflect the extra 
operations required to compute the offset for the doubly dimensioned array.


Mike

At 03:40 PM 11/11/2009, Peter St. John wrote:
>The difference between:
>array1(1:60000)
>array2(1:2, 1:30000)
>
>would be reflected in the size of the executable, not the size of the data.
>Right?
>Peter
>
>
>On Wed, Nov 11, 2009 at 9:01 AM, Michael H. Frese 
><<mailto:Michael.Frese at numerex-llc.com>Michael.Frese at numerex-llc.com> wrote:
>At 06:43 PM 11/10/2009, Larry Stewart wrote:
>
>
>>On Tue, Nov 10, 2009 at 8:30 PM, amjad ali 
>><<mailto:amjad11 at gmail.com>amjad11 at gmail.com> wrote:
>>HI,
>>suppose we have four arrays with same number of elements say 
>>60000., but different dimensions like:
>>array1(1:60000)
>>array2(1:2, 1:30000)
>>array3(1:2, 1:300, 1:100)
>>array4(1:4, 1:15, 1:10,  1:100)
>>
>>Does each of these arrays in fortran will occupy same amount of memory?
>>For sending/receiving each of these, Does MPI has the same (or 
>>nearly same) overhead? or any significantly different overhead is 
>>involved in handling each of these arrays (by MPI)?
>>
>>They should take the same amount of space and have nearly identical 
>>transfer times with MPI.
>>(If you send the whole thing)
>>
>>-L
>
>Those four array descriptors can all apply to exactly the same 
>space, via an 'equivalence' statement.  They are all laid out in 
>memory just like array1.
>
>Thus, they can each be transmitted by exactly the same MPI send.
>
>
>Mike
>
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