What is the fastest way of appending an element to an array?

Question

This is a follow-up question to How to append an element to an array in MATLAB? That question addressed how to append an element to an array. Two approaches are dis

Answer 1

How about this?

function somescript

RStime = timeit(@RowSlow)
CStime = timeit(@ColSlow)
RFtime = timeit(@RowFast)
CFtime = timeit(@ColFast)

function RowSlow

rng(1)

A = zeros(1,2);
for i = 1:1e5
    A = [A rand(1,1)];
end

end

function ColSlow

rng(1)

A = zeros(2,1);
for i = 1:1e5
    A = [A; rand(1,1)];
end

end

function RowFast

rng(1)

A = zeros(1,2);
for i = 1:1e5
    A(end+1) = rand(1,1);
end

end

function ColFast

rng(1)

A = zeros(2,1);
for i = 1:1e5
    A(end+1) = rand(1,1);
end

end

end

For my machine, this yields the following timings:

RStime =

30.4064

CStime =

29.1075

RFtime =

0.3318

CFtime =

0.3351

The orientation of the vector does not seem to matter that much, but the second approach is about a factor 100 faster on my machine.