matlab pointer doesn't help speed up

function main()
t = 0:0.03:100;
t_size = length(t);
data_y = randn(1,t_size);
p_t = libpointer('doublePtr',t);
p_data_y = libpointer('doublePtr',data_y);
tic
disp(p_data_y.Value(1));
disp(data_y(1));
toc

tic
changePtrValue(p_data_y);
disp(p_data_y.Value(1));
toc

tic
data_y1 = changeValue(data_y);
disp(data_y1(1));
toc

clear p_t
clear p_data_y
end

function changePtrValue(p_data)
p_data.Value(1) = 1;
for i = 1:numel(p_data.Value)
p_data.Value(i) = p_data.Value(i)+1;
end
end

function data_out = changeValue(data_in)
data_out = data_in;
data_out(1) = 2;
for i = 1:numel(data_out)
data_out(i) = data_out(i)+1;
end
end
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result
using ptr: 0.113141 sec
nomar way: 0.000728 sec

matlab already has good way. they don't need the pointer for speed up.