There is no more efficient way.
As Walter mentioned already accessing the indices is faster, when you use integer types. But then you have to think twice, or better 8 times, if a saturation is possible. If you are in doubt, use at least UINT32 or stay at doubles. Example:
No advantage for integers:
x = rand(1, 1e4);
for i = 1:1e4
y = x(i);
end
for i = uint32(1):uint32(1e4)
y = x(i); % <- same speed as DOUBLE index
end
An integer loop index is faster, if it is used for indexing inside the loop:
x = rand(1, 1e4);
for i = 1:1e4
y = sum(x(1:i));
end
u1 = uint32(1);
for i = uint32(1):uint32(1e4)
y = sum(x(u1:i)); % <- faster than DOUBLE index vector
end
But the integer saturation does not cause an error message:
for i = uint8(1):uint8(1e4) % !!! uint8(1e4) is 255!
Creating the index vector explicitly is slower:
v = 1:1e4;
for i = v % Slower
y = x(i);
end
for i = 1:1e4 % Faster
y = x(i);
end
Using an explicit data vector can be nicer, but the speed depends on the details:
v = rand(1,1e4);
for av = v
y = av;
end
