Global addition
S = gplus(X)
S = gplus(X,targetlab)
S = gplus(X) returns the addition of the
variant array X from each worker. The result S is
replicated on all workers.
S = gplus(X,targetlab) performs the addition,
and places the result into S only on the worker
indicated by targetlab. S is
set to [] on all other workers.
With four workers,
S = gplus(labindex)
calculates S = 1 + 2 + 3 + 4, and returns 10 on
all four workers.