User`s guide

11 Functions — Alphabetical List

11-44

To use a default dimension, specify codistributor1d.unsetDimension for

that argument; the distribution dimension is derived from gsize and is set to

the last non-singleton dimension. Similarly, to use a default partition, specify

codistributor1d.unsetPartition for that argument; the partition is then derived

from the default for that global size and distribution dimension.

The local part on worker labidx of a codistributed array using such a codistributor is of

size gsize in all dimensions except dim, where the size is part(labidx). The local part

has the same class and attributes as the overall codistributed array. Conceptually, the

overall global array could be reconstructed by concatenating the various local parts along

dimension dim.

Examples

Use a codistributor1d object to create an N-by-N matrix of ones, distributed by rows.

N = 1000;

spmd

codistr = codistributor1d(1); % 1st dimension (rows)

C = ones(N,codistr);

end

Use a fully specified codistributor1d object to create a trivial N-by-N codistributed matrix

from its local parts. Then visualize which elements are stored on worker 2.

N = 1000;

spmd

codistr = codistributor1d( ...

codistributor1d.unsetDimension, ...

codistributor1d.unsetPartition, ...

[N,N]);

myLocalSize = [N,N]; % start with full size on each lab

% then set myLocalSize to default part of whole array:

myLocalSize(codistr.Dimension) = codistr.Partition(labindex);

myLocalPart = labindex*ones(myLocalSize); % arbitrary values

D = codistributed.build(myLocalPart,codistr);

end

spy(D==2);