clear
x0 = 10;
s0 = 2;
N = 3;
Mrep = 1e4;

x = x0 + s0 * randn( N, Mrep );
s_MV = std( x, 1 );
s_cor = std( x );
%s_MV = zeros( Mrep, 1 );
%s_cor = zeros( Mrep, 1 );
%for qM = 1: Mrep
%%  for i = 1:N
%%    x(i) = x0 + s0 * randn;
%%  end
%  x = x0 + s0 * randn( N, 1 );
%  s_MV(qM) = std( x, 1 );
%  s_cor(qM) = std( x );
%end