For those interested to know what that loop produces:
s1 = 1; % minimum bin value
s2 = 1000; % maximum bin value we would like
m = 1.031; % scaling factor, each bin will be m*the last one in size
xi = s1; % starting point
while 1
xi(end+1) = xi(end)*m; % new bin is the last one*m
if xi(end)>s2 % when we exceed value s2, stop
break
end
end
display(xi)
Just for fun, without CUMPROD:
s1 * m.^(0:ceil(log(s2/s1)/log(m)))
