You seem to be writing matlab code using C syntax. In matlab if conditions don't need to be enclosed in () brackets
if a(i) > 7
and more importantly the body of if must not be enclosed in {}
{ error('Value exceeds the Number of Struct Rows')
}
attempts to create a cell array containing the output of error and since error doesn't have any output, the actual error message produced by the above would be: Error using error. Too many output arguments.
So, that part should be:
if a(i) > 7
error('Value exceeds the Number of Struct Rows');
end
or more simply
assert(a(i) <= 7, 'Value exceeds the Number of Struct Rows')
Even better get rid of the loop:
a = input('Enter a vector of seven numbers using [1 2 3 4 5 6 7] syntax:');
assert(all(a <= 7), 'At least one value exceeds the number of rows');
In C and in matlab == is the comparison operator, not the assignment. Matlab doesn't know how to compare structure.
Once again, a loop is not needed:
out(a) = out; %reorders the elements of out.
Of course, since you never check that all the elements of a are different, you may well end up with duplicated elements in your reordered structure (and others missing).
