Create Composite object
C = Composite()
C = Composite(nlabs)
C = Composite() creates a Composite object
on the client using workers from the parallel pool. The actual number
of workers referenced by this Composite object depends on the size
of the pool and any existing Composite objects. Generally, you should
construct Composite objects outside any spmd statement.
C = Composite(nlabs) creates a Composite
object on the parallel pool set that matches the specified constraint. nlabs must
be a vector of length 1 or 2, containing integers or Inf.
If nlabs is of length 1, it specifies the exact
number of workers to use. If nlabs is of size 2,
it specifies the minimum and maximum number of workers to use. The
actual number of workers used is the maximum number of workers compatible
with the size of the parallel pool, and with other existing Composite
objects. An error is thrown if the constraints on the number of workers
cannot be met.
A Composite object has one entry for each lab; initially each
entry contains no data. Use either indexing or an spmd block
to define values for the entries.
The following examples all use a local parallel pool of four workers, opened with the statement:
p = parpool('local',4);This example shows how to create a Composite object with no
defined elements, then assign values using a for-loop
in the client.
c = Composite(); % One element per worker in the pool for w = 1:length(c) c{w} = 0; % Value stored on each worker end
This example shows how to assign Composite elements in an spmd block.
c = Composite(); spmd c = 0; % Value stored on each worker end
This example shows how to assign the elements of a Composite with a value from each worker.
c = Composite(); spmd c = labindex; end c{:}
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4This example shows how to use a distributed array vector to set the values of a Composite.
d = distributed([3 1 4 2]); % One integer per worker spmd c = getLocalPart(d); % Unique value on each worker end c{:}
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2A Composite is created on the workers of the existing
parallel pool. If no pool exists, Composite starts
a new parallel pool, unless the automatic starting of pools is disabled
in your parallel preferences. If there is no parallel pool and Composite cannot
start one, the result is a 1-by-1 Composite in the client workspace.