sliced variables

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

Answer 1

[Edric Ellis]

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.

[Facosoft]

Thanks

Answer 2

[Walter Roberson]

zeros(:,15) is not valid syntax to call the zeros() function.

[Facosoft]

Thanks