Process Control: Modeling, Design, and Simulation

M1.7. For Loops

A for loop in MATLAB is similar to a DO Loop in FORTRAN. The main difference is that the FORTRAN DO loop must have an integer index variable; for does not have this restriction. An example of a for loop that is virtually identical to a DO loop is

» for k = 1:5001;
  t(k) = (k-1)*0.01;
  y(k) = sin(t(k));
end

Another way of implementing the same loop is to increment t from 0 to 50 in intervals of 0.01:

» k = 0
» for t = 0:0.01:50;
  k = k + 1;
  y(k) = sin(t);
end

The developers of MATLAB highly recommend that you use the vectorized version of the above for loops:

t = 0:0.01:50;
y = sin(t);

since the computation time for this method is over 200 times faster than the nonvectorized methods.