User`s guide

5 Math with Codistributed Arrays
5-4
Codistributed Arrays
With replicated and variant arrays, the full content of the array is stored in the
workspace of each worker. Codistributed arrays, on the other hand, are partitioned into
segments, with each segment residing in the workspace of a different worker. Each
worker has its own array segment to work with. Reducing the size of the array that
each worker has to store and process means a more efficient use of memory and faster
processing, especially for large data sets.
This example distributes a 3-by-10 replicated array A across four workers. The resulting
array D is also 3-by-10 in size, but only a segment of the full array resides on each
worker.
spmd
A = [11:20; 21:30; 31:40];
D = codistributed(A);
getLocalPart(D)
end
WORKER 1 WORKER 2 WORKER 3 WORKER 4
| | |
11 12 13 | 14 15 16 | 17 18 | 19 20
21 22 23 | 24 25 26 | 27 28 | 29 30
31 32 33 | 34 35 36 | 37 38 | 39 40
For more details on using codistributed arrays, see “Working with Codistributed Arrays”
on page 5-5.