MATLAB: Sliced variables

MATLABsliced variable

I intend to write a value, say, 90, in many times, say 15 (actually want it in 1440 times) inside a parfor loop.
The first approach using for loop generated this error – 'valid indices for 'a' are restricted in PARFOR loop'
parfor n=1:35
  a=zeros(:,15); % the variable is indexed but not sliced

  for k=1:15
    a(:,k)= 100
  end
end
the second approach (vectorization)
parfor n = 1:35
  a=zeros(:,15); % the variable is indexed but not sliced
  a(:,1:15)=90; 
end
generated same error and so PARFOR loop cannot run due to the way variable 'a' is used.
I want to actually slice the variable 'a' not just indexed so as to avoid unnecessary communication overhead, please how do I go about this? Kindly assist.
Felix

Best Answer

To slice the variable 'a', you need to use a subscript list that contains:
  1. One instance of the loop variable
  2. Other subscripts which are either constant literal values or ':'
So, for example, in the following case, 'a' will be a sliced output:
parfor n = 1:35
  tmp = 90 * ones(1, 15);
  a(n, :) = tmp;
end
which creates 'a' as a 35x15 matrix with each element containing the value 90.
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